Day 1 is a full body circuit, and it teaches you how the whole program works in one card. Five moves: 10 squats, 10 punches, 10 lunges, 10 shoulder taps in a plank and a 10-count plank hold. Do all five in that order without stopping and that is one set. Then rest for up to 2 minutes and go again. The card gives three options for how many sets to do: Level I is 3 sets, Level II is 5 and Level III is 7. Pick whichever you can finish today with good form; you can move up a level on any day you feel ready.

The circuit runs from big to small. Squats and lunges load the legs and hips, the biggest muscles you have, so the heart rate climbs early. Punches keep it up while giving the legs a breather, then the plank work turns the effort inward: shoulder taps ask the arms and shoulders to carry you one hand at a time, and the hold at the end asks everything to stay still under load. Reps are totals throughout, so 10 lunges means 5 per leg, alternating, and 10 shoulder taps means 5 per hand. A count is a slow steady one, roughly one per second.

Squat by pushing your hips back and down, chest up, heels flat, until your thighs are close to parallel with the floor. Punch from a boxer stance with the fists up, one arm at a time, turning the shoulder into each one. Step into the lunge and lower the back knee until it hovers just above the floor. In the plank, hands under the shoulders, body in one line from head to heels: tap the opposite shoulder without letting the hips swing, then hold that line for the count.

Ninety days start with one honest circuit, and this is it.

Make it Harder: Hold the plank for a 20-count instead of 10 at the end of every set.

Make it Easier: Take the plank hold and shoulder taps from your knees and with the reps unchanged.

Day 2 is a cardio circuit built from two moves that trade places. Read the list top to bottom: 10 high knees, 4 climbers, 10 high knees, 4 climbers, and so on for five rounds of each. That whole list is one set. Rest up to 2 minutes, then repeat for 3, 5 or 7 sets depending on your level. There is no pause between the high knees and the climbers; the point is to keep moving from standing to the floor and back without letting the pace fall.

High knees are the engine here: a running motion on the spot with each knee driven up to hip height, 10 reps meaning 5 per leg. Climbers put you in a plank and pull one knee toward the chest at a time, 4 reps being 2 per leg. The constant change of level, up on your feet and then down on your hands, is what makes a short list feel like a long run. By the third round the transitions are doing as much work as the exercises.

On high knees, stay light on the balls of your feet and pump the arms as if you were sprinting; height beats speed at first. In the climbers, keep the hands under the shoulders and the hips level with the back, and bring the knee in far enough that the thigh comes close to the chest. Get up and down cleanly rather than collapsing into the plank.

Two exercises, one rule: never let the floor slow you down.

Make it Harder: Double the climbers to 8 per round and keep the high knees at 10.

Make it Easier: Turn the high knees into march steps at the same count and take the climbers slowly.

Day 3 takes it to the floor for abs. The circuit is 5 sit-ups, 10 sitting twists, 10 flutter kicks, 10 scissors and 5 leg raises, done in order for one set, with up to 2 minutes rest and 3, 5 or 7 sets by level. Everything happens on your back or sitting up, and nothing is rushed: this card is about tension, not tempo.

The five moves split the work between the upper and lower abs. Sit-ups curl the whole torso up off the floor with the knees bent and the arms reaching forward. Sitting twists lean the trunk back with the feet lifted and turn the hands from side to side, 10 reps meaning 5 per side. Flutter kicks and scissors both keep the legs hovering and moving, one up and down and the other crossing side to side, and both count every kick, so 10 is 5 per leg. Leg raises finish by lifting both straight legs together from just above the floor to vertical and lowering them again.

Roll up through the sit-up rather than yanking with the neck, and control the way back down. In the twists, keep the chest tall and turn from the waist. For every lying leg exercise, press the lower back into the floor and keep it there; if the back starts to arch, raise the legs a little higher until it settles. The legs never rest on the floor mid-set.

Slow legs, quiet back, five moves: that is how the abs get introduced here.

Make it Harder: Keep both hands off the floor during the sitting twists and touch the floor on each side with your fingertips.

Make it Easier: Bend the knees for the flutter kicks and scissors and take the leg raises one leg at a time.

Day 4 works the upper body with no weights at all. The circuit is 10 arm raises, 10 arm circles, a 10-count hold with the arms out to the sides, 10 arm scissors, 10 scissor chops and a 10-count hold with the arms straight out in front. One set is the full run through, rest is up to 2 minutes, and the level choice is 3, 5 or 7 sets as on every circuit card.

With nothing to lift, time is the resistance. The arms come up to shoulder height in the raises and stay there for the circles, 10 in total, so 5 in each direction, then simply stay up for the first hold. Arm scissors cross and uncross the arms in front of the chest and scissor chops sweep them wide and back together, both keeping the arms level the whole time, before the second hold parks them straight ahead. Six moves in a row with the arms never dropping below shoulder height is a lot more shoulder than it looks on paper.

Keep the arms straight and the shoulders down away from the ears on every move; the moment the shoulders creep up, the neck takes over. Make the circles small and controlled rather than big and loose. In the scissors and chops, alternate which arm crosses on top. In both holds, the arms stay perfectly level for the whole count, palms down, with the fingers reaching away from you.

No dumbbells needed; your own arms will weigh plenty by the sixth move.

Make it Harder: Hold the arms out for a 20-count at both holds instead of 10.

Make it Easier: Shake the arms out for a few seconds between exercises and keep the counts as printed.

Day 5 is a stretching sequence, and it is the first lighter day of the program. Six positions, each held for a slow 10-count. Move through all six on one side, then repeat the entire sequence on the other side, so every stretch gets both sides before you are done. No sets, no rest timer: one unhurried pass through each side.

The card follows the legs from top to bottom. Position 1 is a kneeling lunge with both arms reaching overhead, opening the front of the back hip. Position 2 is a standing quad stretch, one foot held behind you and the opposite arm reaching up for balance. Position 3 is a wide stance with the hands reaching down toward one foot, lengthening the back of that leg. Position 4 is a low lunge with both hands on the floor beside the front foot. Position 5 is a side lunge with one leg straight and the other bent, and position 6 is seated with one leg straight out in front while you fold toward it.

Ease into each position on the exhale and stop where the stretch is clear but not sharp. In the kneeling lunge, push the hips forward rather than arching the lower back. In the quad stretch, keep the knees together and stand tall. In the seated fold, hinge from the hips and keep the back long instead of rounding to reach the foot. Count slowly and breathe through every hold.

Four days of work, one day of letting the muscles catch their breath.

Make it Harder: A stretching day is not where you push; if it feels too easy, hold each position for a 20-count and keep the sequence as it is.

Make it Easier: Shorten every stance and rest a hand on something solid in the standing positions.

Day 6 is the first challenge day: side leg raises, and only side leg raises. The card sets a total for the day by level, 50 reps for Level I, 60 for Level II and 70 for Level III, and tells you to split it into manageable sets. There is no rest timer and no set count. Do however many you can with good form, rest as long as you need, and keep going until the total is done. Reps are totals, so 50 means 25 per leg.

Challenge days are the program's way of building volume in one movement without a circuit around it. A standing side leg raise lifts one straight leg out to the side while the other keeps you upright, and it works two things at once: the hip of the leg that moves and the balance of the leg that does not. Fifty of them in a row is not the idea; ten sets of five is just as valid as five sets of ten. What matters is that every rep is a full one.

Stand tall with the hands up in a loose guard, as drawn, and lift the leg directly out to the side with the toes pointing forward, not up. Go as high as the hip allows without leaning away from the leg. Lower it under control and change legs every rep, or do a block on one leg and then match it on the other; either way the totals stay even.

One movement, a big number and as many sets as it takes.

Make it Harder: Pause for a 2-count at the top of every raise before lowering the leg.

Make it Easier: Steady yourself against a wall with one hand and work in sets of five.

Day 7 is the program's first high intensity interval session, and the timing is different from every card so far. Three moves, 20 seconds each, done back to back: 20 seconds of march steps, 20 seconds of high knees and 20 seconds of butt kicks. That 60 seconds of work is one set. Rest for exactly 60 seconds, not the usual 2 minutes, and repeat for 3, 5 or 7 sets by level. Use the timer on the page rather than counting reps.

The three intervals climb in pace. March steps lift the knees high at a walking rhythm with the arms driving, high knees turn the same movement into a run on the spot, and butt kicks flip it around so the heels flick up toward the glutes. Because there are no rep targets, the only measure is how much you fit into each 20 seconds, and that is exactly what makes interval training work: the effort is meant to be high for a short time, then you recover, then you do it again.

Keep the arms working on all three; they set the tempo for the legs. Land softly on the balls of the feet and keep the chest up rather than leaning back on the high knees. On butt kicks, the knees stay pointing down while the heels come up. Go as fast as you can hold for the full 20 seconds, not as fast as you can hold for 5.

Sixty seconds on, sixty off: the first week ends at a sprint.

Make it Harder: Cut the rest to 30 seconds between sets.

Make it Easier: Swap the high knees for a second round of march steps and keep every interval at 20 seconds.

Day 8 is the second abs day, with a different set of five: 10 air bike crunches, 10 long arm crunches, 10 flutter kicks, 5 leg circles and 5 reverse crunches. Circuit format as always, up to 2 minutes rest, 3, 5 or 7 sets. Only the flutter kicks carry over from Day 3, so most of this card is new.

Air bike crunches twist the elbow toward the opposite knee while the other leg extends, cycling side to side, 10 reps being 5 per side. Long arm crunches keep the arms straight overhead and lift the shoulders off the floor with the arms following, which lengthens the lever and makes a small crunch cost more. Leg circles trace a circle in the air with both straight legs held together; do all 5 in one direction and reverse the direction on your next set. Reverse crunches bring the knees toward the chest and lift the hips off the floor, working the lower abs from the other end.

Keep the lower back pressed down on every lying move. In the air bike, rotate the shoulder toward the knee rather than just the elbow. In the long arm crunch, the arms stay beside the ears and the chin stays off the chest. Make the leg circles small enough that the back never lifts, and in the reverse crunch, lift the hips with the abs, not by rocking.

Four new moves and one old friend, all aimed squarely at the middle.

Make it Harder: Make the leg circles bigger and slower, taking a full 4-count for each one.

Make it Easier: Bend the knees during the leg circles and put a hand under each hip for support.

Day 9 is a six-move full body circuit that runs the same pattern twice with a different ending: 10 jumping jacks, 10 shoulder taps, 4 plank jacks, then 10 jumping jacks, 10 shoulder taps and 4 plank jump-ins. All six in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. You go from standing to plank and back up twice per set.

The repeated pair keeps the heart rate high while the plank work keeps the shoulders busy, and the two finishers add a jump to the plank each time. A plank jack keeps the hands planted while the feet jump apart and back together; a plank jump-in keeps the hands planted while both feet jump forward toward the hands and back out. Only 4 of each, but they land at the end of a stretch of plank work, which is when the shoulders are already asking questions.

Jumping jacks are full range: hands touch overhead, feet land wider than the shoulders. Shoulder taps stay strict, hips level, 5 taps per hand. In plank jacks, keep the hips low and the feet landing softly. In plank jump-ins, bring the feet as close to the hands as your hips allow and jump straight back to a clean plank rather than a sagging one.

Up, down, up, down, and every trip to the floor costs a little more.

Make it Harder: Take the plank jacks and plank jump-ins to 8 each.

Make it Easier: Step the feet out and in for the plank jacks, and step the feet forward one at a time for the jump-ins.

Day 10 is a balance and coordination sequence, the second lighter day of the program. Six positions flow into each other, and the instruction is to move from one to the next quickly, then repeat the whole sequence 10 times in total, which is 5 rounds leading with each leg. No sets, no rest timer, just one smooth pass through the ten rounds.

The card starts low and finishes high. Position 1 is a kneeling lunge with both arms reaching overhead. Position 2 folds forward from that lunge with the hands reaching down to the floor. Position 3 rises into a wide stance with the hands on the floor. Position 4 stands up and lifts one knee, holding the foot with the hand. Position 5 hugs that knee to the chest with both hands. Position 6 sends the same leg straight back behind you, standing on the other leg. Every position after the third is done on one foot, so the balance work is in the second half.

Move with control rather than rushing; quickly means no dawdling between positions, not sloppy transitions. In the kneeling lunge, keep the front knee over the ankle. In the standing positions, find a fixed point at eye level and keep your gaze there. When the leg goes back in position 6, keep the hips level and the standing knee soft. Alternate the leading leg every round.

Ten smooth rounds and the body learns something no set of reps can teach.

Make it Harder: Balance is not built by force, so instead of adding load, slow each single-leg position to a 3-count before moving on.

Make it Easier: Touch something solid with your fingertips during positions 4, 5 and 6 and keep the rounds at 10.

Day 11 is a cardio circuit in list form: 10 jumping jacks, 1 plank jack, and that pair repeated five times over is one set. Rest up to 2 minutes and repeat for 3, 5 or 7 sets by level. The single plank jack is not a typo. It is there to make you get down to the floor and back up five times in a row.

Ten jumping jacks take about 10 seconds; the plank jack takes about the same once you count the trip down, the jump of the feet out and in, and the trip back up. That is the design. Jumping jacks keep the pulse up, and the trip to the floor keeps you from settling into a rhythm. By the fourth round the transition itself is the hardest part, which is the same idea Day 2 used with climbers, now with a jump instead of a knee drive.

Full jumping jacks: hands overhead, feet wide, landing soft. For the plank jack, place the hands under the shoulders, step or jump back into a straight plank, jump the feet apart and together once, and come back up to standing in the same controlled way. Do not skip the plank in the hurry to get back up.

Fifty jacks and five floor trips per set; the floor is where the work hides.

Make it Harder: Do 2 plank jacks each round instead of 1.

Make it Easier: Step the feet apart and together in the plank instead of jumping.

Day 12 is the first abs and core card, which means plank work joins the floor work. The circuit is 10 plank arm raises, 10 plank leg raises, 6 reverse crunches, 10 flutter kicks and 6 heel taps. One set is all five, up to 2 minutes rest, 3, 5 or 7 sets by level.

The two plank moves are the new element. A plank arm raise lifts one straight arm forward to shoulder height while the other supports you; a plank leg raise lifts one straight leg behind you while the other stays planted. Both are done in a full plank on the hands, both alternate sides every rep, and both are 10 in total, so 5 per side. They train the core to resist rotation, which is different from the crunching and kicking that follows. Reverse crunches and flutter kicks return, and heel taps finish with a small side-to-side crunch, reaching each hand toward the heel on the same side, 6 in total.

In both plank raises, the hips must not tilt; imagine keeping a tray level on your lower back. Lift the arm or leg only as high as you can without the rest of the body moving. In the heel taps, keep the shoulders off the floor throughout and reach with the ribs, not just the arm. Flutter kicks stay small and fast with the back pressed down.

Planks that move and crunches that reach, and the middle has to hold all of it together.

Make it Harder: Bring the feet together for both plank raises so the hips have a narrower base to balance on.

Make it Easier: Do the plank arm raises and plank leg raises from your knees and keep the floor work as printed.

Day 13 is a full body circuit that stays close to Day 1 and adds two twists. The circuit is 10 squats, 10 punches, 10 squat hold punches, 10 shoulder taps and 10 thigh taps. Circuit format, up to 2 minutes rest, 3, 5 or 7 sets by level. Two of the five are new.

Squat hold punches combine the first two exercises: sink into a squat, stay there, and throw 10 punches without standing up. The legs hold while the arms work, and the heart rate goes up because both halves of the body are busy at once. Thigh taps take the plank shoulder tap idea and send the hand the other way: in a plank, one hand reaches back to tap the top of the same-side thigh, then returns to the floor. It is a longer reach than a shoulder tap, so the plank has to be steadier to allow it. Both new moves are 10 in total, alternating, 5 per side.

On squat hold punches, keep the thighs near parallel and the weight in the heels; if the squat rises as the punches speed up, slow the punches. Punch with a turn of the shoulder rather than a flick of the arm. In thigh taps, keep the feet a little wider than usual and rotate as little as possible; the hips stay square to the floor while the hand travels.

Same squats, same punches, new combinations: the program is starting to stack.

Make it Harder: Add a 10-count squat hold before the squat hold punches in every set.

Make it Easier: Reach for the hip instead of the thigh on the thigh taps and keep the squat hold punches shallow.

Day 14 is a challenge day again, and this time the leg goes backward. Back leg raises: 50 reps for Level I, 60 for Level II, 70 for Level III, split into manageable sets. No rest timer, no set count. Reps are totals, so 50 is 25 per leg, and you can alternate legs every rep or work one leg for a block and then the other.

Where Day 6 lifted the leg out to the side, today lifts it straight back, and that changes the muscle doing the work. A standing back leg raise is a glute exercise first and a lower back exercise second, with the standing leg doing quiet balance work underneath. It looks small because the range is small: a straight leg only goes so far behind you before the back starts to arch, and the arch is the thing to avoid. Fifty clean short ones beat fifty big sloppy ones.

Stand tall, arms relaxed at your sides as drawn, and lift the leg straight back with the toes pointing down. Squeeze the glute at the top and stop the moment the lower back wants to take over. Keep the torso upright; the body should not tip forward as the leg goes back. Lower under control and repeat.

Two weeks in, and the second challenge finds the muscles you sit on.

Make it Harder: Add a pulse at the top of every raise: lift, lower an inch, lift again, then bring the leg down.

Make it Easier: Hold a chair or wall with one hand and split the total into sets of ten.

Day 15 is a tendon strength sequence, done lying on your side, and it is a lighter day with a specific rule: the top leg stays off the floor for the entire sequence. Five moves in order, one leg: a 10-count hold, 10 side leg raises, 10 leg swings, 10 fast kicks and 10 slow kicks. Then change sides and do the whole sequence again with the other leg. Because the card says to change legs and repeat, these reps are per leg, not totals.

Tendon work is about time under low load rather than big effort. The hold starts with the leg lifted and still. Side leg raises take it higher and back down without ever touching the bottom leg. Leg swings move it forward and back along the floor line. Fast kicks and slow kicks both extend the leg out from a bent knee, first at speed and then at a crawl. Fifty movements plus a hold with the leg never resting is what builds the small stabilising muscles around the hip that circuits do not reach.

Lie on your side propped on the forearm, hips stacked, the bottom leg straight or slightly bent for support. Keep the toes of the working leg pointing forward, not up, on the raises and swings. Kick from the knee with the thigh staying still. If the leg starts to shake, that is the tendon work happening; slow down rather than putting the foot down.

One leg, five moves, no touching down; the work is in the not resting.

Make it Harder: Tendon days are built on light effort held for time, so leave the reps alone and hold the 10-count at the top of every side leg raise for an extra count instead.

Make it Easier: Lower the working leg to hover just above the bottom leg between exercises without resting it, and shorten the hold to a 5-count.

Day 16 is interval training with the Day 7 timing: three 20-second intervals back to back for a 60-second set, 60 seconds rest, 3, 5 or 7 sets by level. The moves are 20 seconds of high knees, 20 seconds of climbers and 20 seconds of jumping jacks. The middle interval is on the floor, so this session adds two level changes to every set.

Day 7 kept you standing the whole time; this one does not. High knees push the pulse up, then the climbers take you down into a plank for 20 seconds of knee drives, and the jumping jacks bring you straight back up to finish. The transition from climbers to jacks is the honest part of the set: the legs have just been working from a plank and now have to jump. It is a small preview of how the program will keep mixing floor work into cardio.

High knees at a pace you can hold for the whole interval, arms driving. In the climbers, get the knee well in toward the chest and keep the hips down; fast is fine, high hips are not. On the jacks, land softly with the feet wide and the hands meeting overhead. Do not walk the transitions; move.

The intervals just learned to use the floor, and the floor does not give it back for free.

Make it Harder: Extend every interval to 30 seconds and keep the 60-second rest.

Make it Easier: Do the climbers with the hands on a raised surface such as a step or low chair.

Day 17 is the Day 3 abs card again, exercise for exercise: 5 sit-ups, 10 sitting twists, 10 flutter kicks, 10 scissors and 5 leg raises, circuit format, up to 2 minutes rest, 3, 5 or 7 sets by level. Two weeks later the card is identical; you are not.

Repeating a card is one of the ways this program measures you without a test. On Day 3 the five moves were new and the goal was to get through them. Today the goal is to do the same thing better: a sit-up with the feet staying down, twists with the chest taller, flutter kicks and scissors with the legs lower, leg raises that lower all the way without the back lifting. If Day 3 was Level I, this is a good day to try Level II; if the sets were hard before, notice how they feel now.

Curl up through the sit-up one segment at a time and lower the same way. In the sitting twists, lean back far enough that the abs have to hold you there, then turn the shoulders rather than swinging the hands. Keep the flutter kicks and scissors low and controlled with the lower back pressed into the floor. Leg raises: straight legs, slow descent, stop before the heels touch.

Same five moves as two weeks ago; the difference is the person doing them.

Make it Harder: Add a 10-count hold with the legs raised straight after the leg raises in every set.

Make it Easier: Cross the arms over the chest for the sit-ups and bend the knees on the scissors.

Day 18 is a full body circuit with the legs in the lead: 10 reverse lunges, 6 side-to-side lunges, 10 calf raises, 10 punches and 10 shoulder taps. All five is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Three lower body moves, one for the arms, one for the plank.

Reverse lunges step back instead of forward, which keeps the front knee steady while the back leg does the lowering; 10 total means 5 per leg. Side-to-side lunges are drawn as a deep lunge to one side with the other leg straight, then a shift across to the other side without standing up in between, 6 reps being 3 per side. Calf raises rise onto the balls of the feet and lower, hands behind the back as drawn. Punches let the legs recover while the pulse stays up, and shoulder taps in a plank close the set.

In the reverse lunge, take a long step back and lower the back knee toward the floor while the front shin stays vertical. In the side-to-side lunge, keep the feet flat and shift the hips across at the same low height. Calf raises go all the way up and all the way down with control. Shoulder taps as ever: hips still, 5 per hand.

Backward, sideways, up onto the toes: the legs get worked in three directions before the arms get a say.

Make it Harder: Hold the bottom of every reverse lunge for a 2-count before stepping back up.

Make it Easier: Do the side-to-side lunges standing up between sides and cut the reverse lunges to 6.

Day 19 is an endurance day and it does not use sets or reps at all. Four holds, 2 minutes each: a squat hold, a raised arms hold, an elbow plank hold and a superman stretch hold. The card says to split into manageable sets if and when necessary, which means each 2 minutes can be broken into pieces if you need it, but the goal is 2 minutes per position and 8 minutes of holding in total.

Two minutes is a long time to stay still. The squat hold sits you at near-parallel with the arms out in front and leaves the legs there. The raised arms hold stands tall with both arms straight forward at shoulder height. The elbow plank puts you on the forearms and toes in one straight line. The superman stretch hold lies you face down with the arms reaching forward and the legs lifted off the floor. Each one loads a different region, legs, shoulders, front of the trunk, back of the trunk, and none of them let you cheat with momentum.

Set a timer rather than counting. In the squat hold, weight in the heels and chest up; if the legs shake, that is normal, if the knees cave inward, stand up and reset. Keep the raised arms level with the shoulders, not the eyes. In the plank, the hips neither sag nor pile up. In the superman, lift the arms and legs together and keep the neck long, looking at the floor. When a hold has to break, rest briefly and restart the clock from where you stopped.

Eight minutes of not moving is harder than most circuits, and now you know that for yourself.

Make it Harder: Do all four holds unbroken with no more than 30 seconds between them.

Make it Easier: Split every hold into four 30-second pieces with a short rest between each.

Day 20 is a stretching day for the upper body, and the format has changed slightly from Day 5: hold each stretch for a slow 10-count on each side, then move on to the next one. Six positions, one pass, no sets. Where a position has no side, hold it once for the count.

Position 1 clasps the hands behind the back with the arms straight, opening the chest, and the inset on the card shows the grip. Position 2 is a shoulder shrug, the shoulders drawn up toward the ears and held. Position 3 reaches one arm overhead and bends it behind the head, the other hand guiding the elbow, for the triceps. Position 4 clasps the hands and reaches straight up overhead. Position 5 folds forward from the hips and lets the arms hang. Position 6 clasps the hands straight out in front and rounds the upper back away from them.

In the chest opener, lift the clasped hands slightly away from the body without leaning forward. Hold the shrug tall, then let the shoulders sink fully when the count ends. In the triceps stretch, walk the hand down the spine and keep the ribs from flaring. In the forward fold, keep the knees soft and let the head be heavy. In position 6, push the hands away as you round the back, feeling it between the shoulder blades.

Three weeks of punches and planks; the shoulders have earned ten counts of nothing.

Make it Harder: This is the day the shoulders rest, so no; if you want more from it, go through the six positions a second time.

Make it Easier: Hold each position for a slow 5-count and skip the forward fold if your back prefers it.

Day 21 is abs and core with a lot of plank traffic: 5 plank walk-outs, 10 plank rotations, 10 flutter kicks, 10 high crunches and 10 sitting twists. All five in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Two of the five start from standing, which is unusual for a floor card.

A plank walk-out begins on your feet: fold forward, put the hands on the floor, walk them out until you are in a full plank, then walk them back and stand up; that is one rep, and 5 of them is a surprising amount of shoulder. Plank rotations start in a full plank and rotate the whole body to one side, the top arm reaching to the ceiling, then return and rotate to the other; 10 total, 5 per side. After that you lie down: flutter kicks, then high crunches with the legs raised and bent while the hands reach up toward the feet, then sitting twists to finish.

Walk the hands out slowly and keep the hips from sagging when you reach the full plank. In the rotation, stack the feet or stagger them, keep the supporting arm straight and turn the hips with the shoulders, not after them. High crunches lift the shoulders, not the chin, and the reach is toward the feet, not past them. Sitting twists stay tall and turn from the waist.

From standing to plank and back, five times, before the floor even gets a turn.

Make it Harder: Hold the full plank for a 3-count at the end of every walk-out before walking the hands back.

Make it Easier: Bend the knees on the walk-outs and do the plank rotations from a knee-down plank.

Day 22 is a cardio circuit in the list format: 10 high knees, 4 knee-to-elbow, repeated five times through for one set. Up to 2 minutes rest, 3, 5 or 7 sets by level. It stays standing the whole way; today the second exercise adds a twist rather than a trip to the floor.

High knees are the same running-on-the-spot drive as on Day 2. Knee-to-elbow is done standing with the hands behind the head: one knee comes up and across while the opposite elbow comes down and across to meet it, then the other side. Four reps is two per side. Because the legs never get to stop, the twist lands on top of an elevated pulse, which turns a simple standing crunch into cardio for the obliques.

Drive the knees to hip height and keep the arms pumping. On knee-to-elbow, keep the elbows wide and bring the knee up to meet the elbow rather than dragging the elbow down to the knee; the twist comes from the trunk. Keep the standing leg soft and the pace continuous from one exercise to the next.

No floor today; the twist alone is enough to keep the middle interested.

Make it Harder: Take the knee-to-elbow to 8 per round and keep the high knees at 10.

Make it Easier: Slow the high knees to march steps and take the knee-to-elbow one careful rep at a time.

Day 23 is the upper body circuit, with three new moves and three from Day 4: 10 shoulder taps, 10 side shoulder taps, 10 bicep extensions, 10 arm scissors, 10 scissor chops and 10 arm circles. Six moves, one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Note that the shoulder taps here are the standing version, not the plank one.

Standing shoulder taps touch the fingertips to the shoulders and then press both arms straight up overhead; side shoulder taps do the same but send the arms out to the sides at shoulder height. Bicep extensions curl the fists up to the shoulders and extend the arms forward with the muscles tensed, using your own resistance in place of a weight. Then the arm scissors, scissor chops and arm circles from Day 4 keep the arms at shoulder height until the end. Every one of the six is 10 in total; the taps and extensions count both arms moving together as one rep.

Reach fully on both kinds of shoulder tap, all the way up or all the way out, then return to the shoulders each time. On bicep extensions, tense the arms as if squeezing a heavy band, both on the way out and on the way back. In the scissors and chops, keep the arms level and alternate which arm crosses on top. Arm circles: 5 forward, 5 back, small and controlled.

Sixty arm movements and not one of them below shoulder height; that is the upper body day.

Make it Harder: Squeeze every rep as if pushing through water, both arms working against imaginary resistance.

Make it Easier: Cut every exercise to 6 reps and keep all six moves in the circuit.

Day 24 is a full body circuit with the Day 9 structure, repeated pairs with a different ending: 10 split jacks, 10 shoulder taps, 6 climbers, then 10 split jacks, 10 shoulder taps and 6 plank rotations. Six moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level.

Split jacks are the new cardio piece: a jumping jack done front to back instead of side to side, one foot forward and one back with the opposite arm reaching up, switching in the air each rep. Ten means 5 with each leg in front. Between the two blocks of split jacks, plank shoulder taps and climbers keep the shoulders and hips working on the floor, and the second block finishes with plank rotations instead, 6 in total, 3 per side, so the set ends on a rotation rather than a run.

Land the split jacks softly with the front knee over the ankle and the back heel lifted; keep the switch quick and the hips low enough that the legs are doing real work. Shoulder taps and climbers with the hips level. In the rotations, turn the whole body as one piece with the supporting arm straight and the top hand reaching for the ceiling.

Front to back instead of side to side, and the plank keeps asking for one more thing.

Make it Harder: Add a 10-count full plank hold after the plank rotations in every set.

Make it Easier: Step the split jacks instead of jumping them and do the rotations from a knee-down plank.

Day 25 is tendon strength again, and this time it is seated. Sit on the floor leaning back on your hands, one knee bent with the foot flat, the other leg straight and lifted off the floor. Then run the sequence with that leg: a 10-count hold, 10 leg raises, 10 high leg raises, 10 moves side-to-side and 10 circles. Change legs and repeat the whole thing. As on Day 15, the working leg stays off the floor throughout and the reps are per leg.

Everything happens in the hip flexor and the front of the thigh, the muscles that lift a straight leg against gravity. The hold sets the baseline. Leg raises lift the leg from hover to about knee height and back; high leg raises take it as far toward vertical as you can. The side-to-side move sweeps the straight leg across and back, and the circles finish by drawing 10 rings in the air, 5 in each direction. Low effort, no rest, lots of time under load: the recipe for tendons.

Keep the chest open and the shoulders down while leaning back on the hands; do not collapse into the lower back. The working leg stays straight with the foot flexed, and the heel never touches the floor between exercises. Make the side-to-side sweeps and the circles small if the hip starts to grip; small and continuous beats big and broken.

Sitting down was never this much work for one leg at a time.

Make it Harder: The tendon day works best light, so keep the reps and simply take every raise at a 3-count up and a 3-count down.

Make it Easier: Bend the working knee slightly through the sequence and shorten the hold to a 5-count.

Day 26 is a challenge day for the shoulders: plank shoulder taps, 60 reps for Level I, 80 for Level II, 100 for Level III, split into manageable sets. No rest timer, no set count, and reps are totals, so 60 is 30 taps per hand. You have done shoulder taps in almost every full body circuit so far; today they get the whole card.

A shoulder tap looks like a shoulder exercise and behaves like a whole body one. Each time a hand leaves the floor, the other arm carries all the weight and the trunk has to stop the hips from tipping toward the free side. One hundred of those is a hundred small balance corrections, and the arms are the least of it. Split them however works: sets of 10 with a short rest, or 20s if the plank holds up. The set structure is yours; the total is not.

Hands under the shoulders, feet a little wider than hip width to give the hips a base, body straight from head to heels. Tap the opposite shoulder and place the hand back where it was. If the hips start swinging with each tap, widen the feet or shorten the set. Rest by standing or kneeling, not by sinking into a saggy plank.

A hundred taps, give or take by level, and the plank finally gets its own day.

Make it Harder: Lift the opposite foot a little off the floor as each hand taps, so the plank balances on two points.

Make it Easier: Widen the feet for a steadier base and take the total in sets of ten.

Day 27 is an abs and core card built almost entirely from holds: a 10-count plank hold, a 10-count raised leg plank hold, 5 circles, a 10-count raised legs hold and 5 more circles. That is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Look at the drawings: both plank holds today are on the forearms, and the circles are done with both legs straight and lifted.

The card runs the front of the body through two kinds of stillness. The elbow plank asks for a straight line from head to heels; the raised leg version takes one foot off the floor for the count and asks the trunk to keep that line anyway. Then you turn over: 5 leg circles with both legs together, a 10-count hold with the legs raised straight and hovering, then 5 more circles. Do the first block of circles in one direction and the second block in the other. Twenty seconds of plank and a ten-second hover do not sound like much until the circles land on either side of them.

Elbows under the shoulders, hands in loose fists or flat, hips level. In the raised leg plank, lift the leg only as high as the hips allow without tilting, and swap the raised leg from set to set. In the circles and the hover, press the lower back into the floor; if it lifts, raise the legs higher. Keep the circles small and the count slow.

Mostly holding still, and the abs will disagree that holding still counts as rest.

Make it Harder: Take every 10-count hold to a 20-count and keep the circles at 5.

Make it Easier: Skip the leg lift in the raised leg plank hold and bend the knees for the circles and the hover.

Day 28 is a full body circuit with one new move up front: 10 hero squats, 10 calf raises, 10 punches, 10 squat hold punches and 10 shoulder taps. All five is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Four of the five you already know; the hero squat is the introduction.

A hero squat, as drawn, starts standing tall with the feet wide and both arms reaching straight overhead, then folds down into a deep squat with the hands reaching toward the floor between the feet, and comes back up with the arms rising to the top again. It is a squat and a full reach in one movement, so the shoulders and back work with the legs. Calf raises follow, hands behind the back, then punches, then squat hold punches to combine the two, then plank shoulder taps to close.

Reach as high as you can at the top of the hero squat and let the arms come down as the hips go back; the chest stays up on the way down and the heels stay flat. Calf raises at full range, up and down under control. In the squat hold punches, keep the squat where it is and do not let the punches lift you out of it. Shoulder taps: hips still, 5 per hand.

Four weeks done, and the squats have learned to reach for the ceiling.

Make it Harder: Add a small jump at the top of every hero squat, landing softly back into the wide stance.

Make it Easier: Reach for the knees instead of the floor on the hero squats and cut the squat hold punches to 6.

Day 29 is high intensity interval training with three kinds of jack: 20 seconds of jumping jacks, 20 seconds of side jacks and 20 seconds of squat jacks, back to back for a 60-second set. Rest 60 seconds, then 3, 5 or 7 sets by level. All three are jumping; none of them go to the floor.

The three jacks step up in cost. Jumping jacks are the standard: feet apart, arms overhead. Side jacks keep the feet jumping apart and together while the arms reach up and over to one side, then the other, adding a bend through the waist to every rep. Squat jacks jump the feet wide into a squat with the arms overhead, then jump them back together into standing with the arms down, so every rep is a squat. Twenty seconds of that last one is where the set is decided.

Soft landings on the balls of the feet throughout; the knees absorb, not the joints. On side jacks, reach up and over with a straight arm and keep the hips facing forward. On squat jacks, land wide with the knees tracking over the toes and sink into a real squat before jumping back; a shallow squat jack is just a slow jumping jack.

Jack, jack, jack: three ways to leave the ground and one minute to do it in.

Make it Harder: Keep the arms overhead for all 20 seconds of squat jacks, even between reps.

Make it Easier: Keep the 20-second intervals and step every jack instead of jumping it.

Day 30 closes the first month with a stretching day done entirely on the floor, and the count has doubled: hold each stretch for a slow 20-count, then move on to the next one. Six positions, one pass, no sides to repeat because every position stretches both sides at once.

Position 1 sits with the soles of the feet together and folds forward over them, opening the hips. Position 2 lies on the back and hugs both knees to the chest. Position 3 is a bridge, lying with the knees bent and the hips lifted, a hold rather than a rep. Position 4 is a superman, face down with the arms and legs lifted. Position 5 presses the hands into the floor and lifts the chest with the hips staying down, arching the front of the body open. Position 6 is a kneeling fold with the arms stretched forward and the forehead toward the floor.

Twenty counts is enough time for a muscle to stop resisting, so breathe slowly and let each exhale take you a little further. In the seated fold, hinge from the hips and keep the back long. In the bridge, squeeze the glutes rather than arching the lower back. In the chest lift, keep the shoulders down and the elbows soft. Finish in the kneeling fold and stay there for the full count.

Thirty days done; the floor gets the last word, and it is a gentle one.

Make it Harder: Today is for lengthening, not loading, so if there is anything left in the tank, walk through the six positions twice and keep every count at 20.

Make it Easier: Cut every count to 10 and keep the knees bent in the seated fold.

Day 31 opens the second month, and the numbers on the card have moved: the base count is now 12 instead of 10. The full body circuit is 12 reverse lunges, 6 side-to-side lunges, 6 kneeling squats, 6 plank walk-outs and 12 shoulder taps. All five in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. One new exercise in the middle.

Kneeling squats are the new arrival: kneel upright with the arms reaching overhead, sit the hips back onto the heels, then rise back to tall kneeling by squeezing the glutes. It is a squat pattern with the shins doing the standing, which takes the knees out of the picture and puts the hips and glutes in charge. Around it, reverse lunges and side-to-side lunges cover the legs in two planes, plank walk-outs return from Day 21 with one more rep, and plank shoulder taps go to 12, so 6 per hand.

In the kneeling squat, keep the torso upright on the way down and drive the hips forward on the way up; the arms stay reaching the whole time. Reverse lunges with the back knee to a hover, 6 per leg. Side-to-side lunges stay low as you shift. Walk the hands out slowly and keep the plank straight before walking back.

A new month, two more reps on everything, and a squat that never stands up.

Make it Harder: Rise from every kneeling squat as slowly as you can, taking a full 3-count to get back to tall kneeling.

Make it Easier: Cut the shoulder taps to 8 and put the hands on the thighs for the kneeling squats.

Day 32 is abs and core with one new move at the top: 6 up and down planks, 6 sit-ups, 12 sitting twists and 12 flutter kicks. Four moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. The three floor moves are old friends at the new count; the plank is the lesson.

An up and down plank moves between the two planks you already know. Start in a full plank on the hands, lower one forearm to the floor, then the other, so you are in an elbow plank, then press one hand back up, then the other, back to the full plank. That whole trip down and up is one rep, 6 in total. It works the shoulders and arms like a slow push-up and works the core because the hips want to swing every time a hand leaves the floor. Sit-ups, twists and flutter kicks follow, all at the second-month numbers.

Alternate which arm leads the way down and which leads the way up from rep to rep. Keep the feet a little wider than usual and the hips as still as you can while the arms move. Sit-ups roll up and roll down. Sitting twists stay tall and lean back. Flutter kicks with the lower back pressed into the floor and the legs low.

Down onto the elbows, up onto the hands, and the plank turns into a moving exercise.

Make it Harder: Take the up and down planks to 10 and leave the rest of the card as it is.

Make it Easier: Do the up and down planks from your knees and cut the sitting twists to 8.

Day 33 is a challenge day, and it is the biggest total so far: climbers, 80 reps for Level I, 100 for Level II, 120 for Level III, split into manageable sets. No rest timer, no set count. Reps are totals, so 80 is 40 per leg, alternating.

Climbers are a cardio exercise done in a plank, which is why the total is high: each rep is one knee driven toward the chest and back, a fraction of a second on a fast day. But a hundred of them is a hundred seconds of plank with the hips moving, so the shoulders and core are working the whole way through, not just the legs. Break the number into sets that keep the pace up: 20 at a time, rest, 20 more. Fast and clean beats slow and staggered on a challenge like this.

Hands under the shoulders, hips level with the back, and the knee coming in far enough that the thigh nears the chest. Do not let the hips rise into a peak as you tire; if they do, the set is over, rest and reset. Keep the head neutral, looking at the floor just ahead of the hands.

The plank gets a cardio workout, one knee at a time, until the number is done.

Make it Harder: Do the total in as few sets as possible, with no set under 30.

Make it Easier: Put the hands on a step or low chair and rest whenever the hips start to rise.

Day 34 is a six-move full body circuit at the second-month count: 12 squats, 12 squat hold punches, 12 calf raises, 12 punches, 12 shoulder taps and 12 plank leg raises. All six is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Nothing new on the card, just more of it, arranged so the legs never get to rest.

Squats go straight into squat hold punches, so the legs go from moving to holding without a break. Calf raises then stand on the same tired legs, and punches, which usually give the legs a rest, come after all that. The plank pair at the end shifts the load to the shoulders and core: shoulder taps, then plank leg raises where one straight leg lifts behind you at a time, 6 per side. The card shares four moves with Day 13, adds two reps to each of them and puts calf raises and plank leg raises on top.

Hips back and chest up in the squats, then stay down for the 12 punches with the thighs near parallel. Calf raises to full height and back down slowly. In the plank leg raises, lift the leg only as high as the hips allow without tilting; the movement is a few inches, not a kick. Shoulder taps with the hips still.

Seventy-two reps a set and the legs get most of them; the second month means it.

Make it Harder: Hold the squat hold punches position for a 10-count after the twelfth punch before standing.

Make it Easier: Run 8 reps on the squats, squat hold punches and plank leg raises and leave the other three at 12.

Day 35 is a lighter day built around five old movements known as the five rites. The instruction is simple: repeat each exercise 5 times, then move on to the next one. Five exercises, one pass, 25 reps in all. No timer, no levels.

The first rite is a 360-degree turn: stand with the arms out to the sides and spin slowly clockwise, 5 full turns. The second is a 90-degree leg raise: lying on the back, lift both straight legs to vertical while lifting the head, then lower. The third is a back stretch: kneel upright, hands on the backs of the thighs, and arch the chest up and back, looking at the ceiling, then return. The fourth is a table stretch: sit with the legs straight and the hands beside the hips, then lift the hips until the body is flat like a table, and lower. The fifth moves between upward dog, chest lifted with the hips low, and downward dog, hips high with the body in a V.

Turn slowly and pick a spot to look at if the room starts to spin; 5 turns is enough to feel it. Keep the lower back pressed down on the leg raises. In the back stretch, lead with the chest rather than the head. Press through the heels to lift into the table and keep the arms straight. Move smoothly between the two dogs, breathing out as you push back into the V.

Five rites, five reps each, and a body that gets moved in directions the circuits never use.

Make it Harder: Not on a rites day; the point is the pattern, not the load, so if 5 is easy, take each rep slower and hold the top of every one for a breath.

Make it Easier: Do 3 reps of each and skip the turns if they make you dizzy.

Day 36 is the upper body circuit at 12 reps: 12 shoulder taps, 12 elbow clicks, 12 bicep extensions, 12 side shoulder taps, 12 chest expansions and 12 arm circles. Six moves, one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Two of the six are new, and both live in front of the face.

Elbow clicks start with the arms bent and the fists up, elbows out wide, then bring the elbows together in front of the face until they touch, and open again. It works the chest on the way in and the upper back on the way out. Chest expansions start with the arms straight out to the sides and sweep them forward until they cross in front of the chest, then open wide again, squeezing the shoulder blades together at the back. Around them, standing shoulder taps and side shoulder taps reach up and out, bicep extensions curl and extend under tension, and arm circles close the card, 6 each way.

On elbow clicks, keep the forearms vertical and get the elbows to actually meet; the last few inches are the work. On chest expansions, alternate which arm crosses on top and make the squeeze at the back count. Keep the shoulders down away from the ears throughout, and keep the arms straight on the taps and circles.

Elbows together, arms wide open, and the chest gets its turn in an equipment-free program.

Make it Harder: Take a 3-count in each direction on every rep, keeping the arms tensed throughout.

Make it Easier: Lower the arms and shake them out for a few seconds between exercises, keeping the reps at 12.

Day 37 is high intensity interval training: 20 seconds of split jacks, 20 seconds of knee-ups and 20 seconds of high knees, back to back for one 60-second set. Rest 60 seconds, then 3, 5 or 7 sets by level. All three are standing; the new one is in the middle.

Knee-ups are drawn with the arms reaching straight up overhead, then one knee driving up as both arms pull down to meet it, and back up. It is a high knee with the whole upper body joining in, so the abs and shoulders work as hard as the leg. Split jacks before it get the legs switching front and back, and high knees after it turn the knee drive into a run. The three intervals share one idea, knees up, and change the arms around it.

Land the split jacks softly with the switch happening in the air. On knee-ups, reach fully at the top and pull the arms down with force, alternating knees; keep the chest up rather than crunching forward. High knees with the arms pumping and the feet light. Aim for a pace you can keep for the full 20 seconds of each interval.

Three intervals, three ways to lift a knee, one minute to get through them.

Make it Harder: Add a fourth 20-second interval of split jacks to every set before the rest.

Make it Easier: Keep the feet on the floor for the split jacks and march the high knees at the same tempo.

Day 38 is abs and core with three new moves: 12 side bridges, 6 body saw, 12 hundreds, 12 air bike crunches and 12 high crunches. Five moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. The first two are on the side and on the forearms; the last three are on the back.

Side bridges lie on one side propped on the forearm, then lift the hips off the floor and lower them, 12 in total, so 6 per side. They work the obliques and the side of the hip in a way nothing on the earlier cards did. Body saw is an elbow plank that rocks backward from the shoulders, pushing the body toward the feet, and pulls forward again; 6 reps, each one a small shift that makes the whole plank harder. Hundreds lie on the back with the knees bent at a right angle and the shoulders lifted, pumping both straight arms up and down beside the hips, 12 pumps. Air bike crunches and high crunches finish.

In the side bridge, keep the body in a straight line from head to feet and lift with the hip, not by pushing off the elbow. In the body saw, keep the plank rigid and let the shoulders do the sliding, a few inches back and forward. On hundreds, keep the shoulders off the floor and the pumps small and quick, breathing steadily. Air bike with the shoulder turning toward the knee; high crunches lifting the shoulders toward the raised feet.

Sideways, backward and pumping: three new angles on the middle in one card.

Make it Harder: Take the body saw to 12 and lift the top leg off the bottom one during the side bridges.

Make it Easier: Do the side bridges from the knees and cut the hundreds to 6 pumps.

Day 39 is a full body circuit with the legs moving sideways: 12 reverse lunges, 12 tap side lunges, 6 side-to-side lunges, 6 plank rotations and 12 shoulder taps. Five moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Tap side lunges are new.

A tap side lunge starts in a wide stance, then sits the hips back and to one side, bending that knee while the other leg stays straight, and reaches down to tap the floor with the opposite hand before standing back up. Twelve total, 6 per side, alternating. It is a shallower, quicker cousin of the side-to-side lunge that follows, which stays low and shifts across. Reverse lunges lead, then the two side moves, then plank rotations and shoulder taps take the work upstairs.

In the tap side lunge, keep both feet flat and the chest up as you reach down; the tap is a hip hinge with a bend in one knee, not a collapse. In the side-to-side lunge, stay at the same low height as you shift. Plank rotations turn the whole body together with the top arm reaching high, 3 per side. Shoulder taps with the hips level.

Down, across, tap, up: the legs get a new direction and the plank keeps its old job.

Make it Harder: Sink into every side-to-side lunge and hold each side for a 2-count before shifting.

Make it Easier: Cut the tap side lunges to 6 and do the plank rotations from a knee-down plank.

Day 40 is a stretching day, mostly standing, with the count to 10 on each side for every position before moving on. Six stretches, one pass, no sets. Where a stretch has no side, hold it once.

Position 1 is a standing quad stretch, one foot held behind you. Position 2 is the overhead triceps stretch, one elbow bent behind the head with the other hand guiding it. Position 3 pulls one arm across the body at chest height with the other hand, for the back of the shoulder. Position 4 is a standing forward fold with the hands reaching toward the feet. Position 5 is a deep squat, feet wide, hands together between the knees with the elbows pressing the knees out. Position 6 is a wide straddle stance, hands on the thighs, shifting the weight toward one side to stretch the inside of the other leg.

Stand tall and keep the knees together in the quad stretch. Guide the elbow gently in the triceps stretch and keep the shoulder down in the cross-body stretch. Let the head hang in the fold. Sit as low as your hips allow in the deep squat with the heels flat, and in the straddle keep the feet turned slightly out and the chest up as you shift. Slow counts, easy breathing.

Forty days in, and the body gets ten quiet counts in six directions.

Make it Harder: There is no harder version of a stretch, only a longer one; take every count to 20 if you want more.

Make it Easier: Keep a hand on a wall for the quad stretch and skip the deep squat if the knees prefer it.

Day 41 is a full body circuit with the arms throwing in two directions: 12 hero squats, 12 overhead punches, 12 punches, 12 squat hold punches and 12 side leg raises. All five is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Overhead punches are new, and the side leg raises are the standing version from the Day 6 challenge.

Overhead punches are thrown from a boxer stance straight up rather than straight ahead, one fist reaching for the ceiling at a time with the other guarding the chin, 12 in total, 6 per arm. They work the shoulders from a different angle than regular punches, which come next, and the squat hold punches after that combine legs and arms again. Hero squats open the card with the full reach and fold, and standing side leg raises close it with 6 per leg, alternating, the hip lifting a straight leg out to the side.

Reach high and sink low on the hero squats. Punch upward with a full extension of the arm and a turn of the shoulder, keeping the other fist up. Regular punches with the same rotation. In the squat hold punches, the squat stays put. Side leg raises with the toes forward and the body upright, not leaning away from the leg.

Punches up, punches out, and the legs holding their ground underneath all of it.

Make it Harder: Sit in a 10-count squat hold before the squat hold punches every set.

Make it Easier: Cut the hero squats and squat hold punches to 8 and keep the punches at 12.

Day 42 is an abs day with punches in it: 6 sit-up punches, 12 sitting punches, 12 flutter kicks, 12 scissors and 12 flutter kicks again. Five moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Two of the five are new, and both borrow from the boxing days.

A sit-up punch is a sit-up that finishes with a punch: lie back with the knees bent, sit all the way up and throw one punch across the body at the top, then lower; 6 reps, alternating the punching arm. Sitting punches keep you at the top of that position, leaning back with the feet lifted, and throw punches without lowering, 12 in total, 6 per arm. Then flutter kicks, scissors and flutter kicks again, the same double dose of leg work that makes the second half of the card longer than it looks.

Sit all the way up before punching and rotate the shoulder into it; the punch is a twist, not a wave. In sitting punches, keep the chest tall and the feet off the floor for the whole 12. On all the leg work, press the lower back into the floor and keep the legs low. Twelve flutter kicks is 6 per leg, each time.

The boxing gloves came to the floor today and the abs do not get to sit this one out.

Make it Harder: Keep the feet off the floor during the sit-up punches as well as the sitting punches.

Make it Easier: Cut the second block of flutter kicks and take the sit-up punches with the feet held under something stable.

Day 43 is a challenge day for the back of the shoulders: reverse angels, 60 reps for Level I, 80 for Level II, 100 for Level III, split into manageable sets. No timer, no set count. Reps are totals, and each rep is one full sweep of both arms.

A reverse angel is done lying face down. Start with the arms stretched straight overhead and hovering off the floor, then sweep them out and back in a wide arc until the hands reach the hips, keeping them lifted the whole way, then sweep back overhead. Every inch of that arc is worked by the rear shoulders and upper back, the muscles that hold the shoulders back against everything else the program has been doing with them. The count is high because each rep is light; the fatigue is in keeping the arms off the floor for the whole set.

Keep the forehead resting or the neck long and the gaze at the floor; do not crane the head up. The arms stay straight and hover a few inches up throughout. Lead the sweep from between the shoulder blades and squeeze them together as the hands pass the shoulders. Rest with the arms down whenever the hover fails, then continue.

Sixty to a hundred sweeps, face down, and the shoulders find out what was behind them all along.

Make it Harder: Sweep the arms at a 3-count each way with the hands hovering a little higher than feels natural.

Make it Easier: Bend the elbows slightly to shorten the arc and split the total into sets of ten.

Day 44 is a cardio circuit in the list format with the second-month count: 12 high knees, 1 plank jump-in, repeated five times for one set. Up to 2 minutes rest, 3, 5 or 7 sets by level. Day 11 sent you to the floor for a plank jack; today the floor trip ends in a jump.

Twelve high knees keep the pace, then you put the hands down, jump or step the feet back into a plank, jump both feet forward toward the hands, jump them back out to plank, and stand up. That whole trip is 1 plank jump-in. It is the same up-and-down structure as the earlier cardio cards with the jump-in doing what the climber and plank jack did before: adding a burst of power and a change of level to every round.

High knees at running pace with the arms working. On the jump-in, land the feet as close to the hands as your hips allow with the knees bent, then jump straight back to a clean plank, not a sagging one, before standing. Move from one exercise to the next without pausing.

Sixty high knees and five jumps into a plank per set; the floor still charges admission.

Make it Harder: Do 3 plank jump-ins each round instead of 1.

Make it Easier: Step the feet in and out one at a time for the jump-ins and cut the high knees to 8.

Day 45 is tendon strength on all fours, the third version of the sequence and the third position. Start on the hands and knees with one leg extended straight back and lifted off the floor. Then, with that leg: a 10-count hold, 10 knee-ins, 10 up and down swings, 10 leg extensions and 10 side leg extensions. Change legs and repeat. The leg stays off the floor for the entire sequence, and as on the earlier tendon days, the reps are per leg.

This version loads the glutes and the back of the hip, where the side-lying and seated versions worked the outside and the front. The hold sets the leg at hip height. Knee-ins pull the knee under the body toward the chest and extend it back out. Up and down swings lift and lower the straight leg. Leg extensions bend the knee with the foot kicking toward the ceiling and straighten it back out. Side leg extensions bend the knee and open the leg out to the side, then return. Fifty movements on one hip with no rest is what builds the tendons around it.

Keep the hands under the shoulders and the hips square to the floor; the temptation is to tilt the hips to lift the leg higher, and the point is not to. In the knee-ins, round the back slightly as the knee comes in and lengthen as it goes out. In the swings, the leg stays straight and the range is modest. On the side extensions, the knee opens to the side, not the whole hip.

Third tendon day, third angle, same rule: the foot does not touch down until the sequence is done.

Make it Harder: Tendon work is light by design, so keep the reps and instead take every movement at half speed, up and down alike.

Make it Easier: Rest the knee down for a breath between exercises and shorten the hold to a 5-count.

Day 46 is 2 minutes of shadowboxing with a rule attached: every 30 seconds, do a double squat, meaning two squats in a row, then straight back to boxing. Each 2-minute round is one set. Rest 2 minutes between sets, and the levels are 3, 4 or 5 sets, not 3, 5 or 7. Use a timer; the round is the measure, not a rep count.

Shadowboxing is free work: move on your toes in a boxer stance and throw combinations at an imaginary opponent, jabs, crosses, hooks, whatever comes, with the feet shifting and the guard up between punches. It is cardio, coordination and shoulder work at once, and because there is no list to follow, the effort is entirely yours to set. The double squat at 30, 60, 90 and 120 seconds sends the legs into four pairs of squats per round, which keeps the lower body honest while the arms do the talking.

Keep the fists up and the elbows in between punches, and turn the shoulder and hip into every one. Stay light on the feet, moving in small steps rather than standing flat. On the squats, hips back, chest up, thighs to parallel, two clean ones, then straight back into the stance. A 2-minute rest is generous; use all of it if the rounds are hard.

Two minutes against nobody, four double squats, and the imaginary opponent never gets tired.

Make it Harder: Make every double squat a pair of jump squats.

Make it Easier: Do a single squat at each 30-second mark and shorten the rounds to 90 seconds.

Day 47 is abs and core with a hold to finish: 6 up and down planks, 12 flutter kicks, 12 scissors and a 10-count hold with the legs raised straight. Four moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Nothing new; the hold at the end is what makes it a card.

Up and down planks open, moving from the hands to the forearms and back, 6 trips, alternating the leading arm. Flutter kicks and scissors follow on the back, 12 of each, meaning 6 per leg. Then the hold: lie back with both straight legs lifted to about knee height and the arms at the sides, and stay there for a slow 10-count. It arrives after 24 kicks on legs that have been hovering already, which is the whole point of putting it last.

Keep the hips still on the up and down planks and the feet a little wide. On the kicks and scissors, press the lower back down and keep the movements small and quick. In the hold, the legs stay together and straight, the lower back stays on the floor and the breathing stays even; if the back lifts, raise the legs higher until it settles.

Twenty-four kicks and then a hold on the same tired legs: the order on the card is the exercise.

Make it Harder: Hover the legs lower for the hold, just above the floor, with the count staying at 10.

Make it Easier: Keep the knees bent for the kicks, the scissors and the hold, and take the up and down planks at a slow, deliberate pace.

Day 48 is a full body circuit with the Day 9 shape and two plank taps you have not met together: 12 jumping jacks, 12 shoulder taps, 6 climber taps, then 12 jumping jacks, 12 shoulder taps and 6 thigh taps. Six moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level.

A climber tap is a climber with a hand involved: in a plank, bring one knee in toward the chest and tap it with the opposite hand, then return both and switch sides, 6 total, 3 per side. It asks the plank to balance on one hand and one foot for a moment, which is harder than either the climber or the shoulder tap alone. Thigh taps at the end reach a hand back to the same-side thigh, the move from Day 13. Between the two blocks, jumping jacks and plank shoulder taps keep the rhythm.

Full range jumping jacks. Shoulder taps with the hips level, 6 per hand. In the climber tap, get the knee well in before the hand meets it and keep the hips down; the tap is a touch, not a grab. Thigh taps with the feet a little wide and the hips square to the floor.

Tap the shoulder, tap the knee, tap the thigh: three planks, three targets, one set.

Make it Harder: Take the climber taps and thigh taps to 12 each.

Make it Easier: Cut the jumping jacks to 8 and take the two tap moves to 3 each.

Day 49 is a challenge day measured in minutes rather than reps: punches, 3 minutes for Level I, 4 minutes for Level II, 5 minutes for Level III, split into manageable sets. Use the timer, throw punches until it runs out, and rest whenever you need to; the clock stops when you do.

Three to five minutes of continuous punching is a long time for the shoulders and a longer time for the lungs. From a boxer stance, alternate straight punches, turning the shoulder into each one and bringing the fist back to the chin. There is no rep target, so the challenge is pace: a steady rhythm you can keep for the full time beats a flurry that burns out at 90 seconds. Split it into rounds if that helps, a minute on and a short breather, until the total is done.

Keep the fists up between punches and the elbows tucked. Punch with a full extension of the arm and a turn of the hip, not just the shoulder. Stay on the balls of the feet with a slight bounce; standing flat makes the minutes drag. Breathe out on the punch, in on the return.

Five minutes of punching at the top level and the shoulders learn the word endurance.

Make it Harder: Do the full time in one unbroken round.

Make it Easier: Split the time into 30-second rounds with 15 seconds between them.

Day 50 is a stretching day for the hips and legs, with a 10-count on each side for every position before moving on. Six positions, one pass, no sets. Half of the card is standing or kneeling and half is lying on the back.

Position 1 is a kneeling lunge with the hands resting on the front knee, opening the front of the back hip. Position 2 is a low lunge with the hands on the floor inside the front foot, sinking the hips toward the floor. Position 3 sits with one leg straight and folds toward the foot, the other leg tucked. Position 4 lies on the back and hugs one knee to the chest with the other leg straight on the floor. Position 5 hugs both knees to the chest. Position 6 crosses one ankle over the other knee and pulls the bottom leg in, the figure-four for the outside of the hip.

Push the hips forward gently in the kneeling lunge without arching the back. Let the hips sink in the low lunge and keep the front knee over the ankle. Hinge from the hips in the seated fold. On the lying positions, keep the head and shoulders relaxed on the floor and pull with the arms, not the neck. Slow counts and long exhales on all six.

Fifty days down, and the hips get a quiet ten counts in every direction they have worked.

Make it Harder: Stretching gets deeper, not harder: let each exhale take you a little further into the same six positions.

Make it Easier: Hold each stretch for a 5-count and skip the low lunge if the hips are not ready for it.

Day 51 is high intensity interval training with the arms doing the jacks: 20 seconds of seal jacks, 20 seconds of step seal jacks and 20 seconds of squat jacks, back to back for one 60-second set. Rest 60 seconds, then 3, 5 or 7 sets by level. Two new moves and one from Day 29.

Seal jacks jump the feet apart and together as usual, but the arms open wide to the sides and clap together in front of the chest instead of going overhead. Step seal jacks are the same arm motion with one foot stepping out to the side and back in place of the jump, alternating sides, a lower-impact version at the same tempo. Squat jacks then take the legs wide into a squat with the arms overhead and back together. The chest and shoulders get 40 seconds of clapping before the legs take the last 20.

Clap with the arms straight and open them fully, feeling the squeeze between the shoulder blades on the way out. Keep the seal jacks light and quick. On the step version, step wide and keep the tempo up even though the feet stay closer to the floor. Squat jacks land wide with the knees over the toes and sink into a real squat every rep.

Clap, step, squat: a minute of jacks that starts in the chest and ends in the legs.

Make it Harder: Replace the step seal jacks with a second 20 seconds of seal jacks.

Make it Easier: Do all three intervals as step versions, stepping the feet out and in without leaving the floor.

Day 52 is abs and core, and every exercise on the card is a plank of some kind: a 10-count plank hold, a 10-count elbow plank hold, 12 plank leg raises, 12 plank arm raises and 6 body saw. Five in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Look at the drawings before you start: the first hold is on the hands, and everything after it is on the forearms.

The two holds set the positions. Then the leg raises and arm raises are done from the elbow plank, not the hand plank you used on Day 12, which changes them: with the forearms down, the base is lower and the shoulders are less involved, so the trunk does more of the work of keeping the hips level while a limb moves. Twelve of each is 6 per side, alternating. Body saw closes on the same forearms, rocking the plank back and forward 6 times. A whole set of plank without ever fully standing up.

Full plank first, hands under the shoulders, then lower to the elbows with the elbows under the shoulders. In both raise variations, the hips do not tilt and the range is small. In the body saw, push back from the shoulders so the body slides toward the feet, then pull forward again, keeping the plank rigid throughout. Breathe; planks are not a breath hold.

Five planks, one set, and the forearms carry most of it.

Make it Harder: Add a 10-count raised leg elbow plank after the elbow plank hold, swapping the leg each set.

Make it Easier: Keep the holds at 10 and cut the leg raises and arm raises to 6 per set.

Day 53 is called a power circuit, and it is written as a list: 2 squats, 12 shoulder taps, repeated five times for one set. Up to 2 minutes rest, 3, 5 or 7 sets by level. Two exercises, ten blocks, and the floor between every one of them.

The numbers look upside down: only 2 squats but 12 shoulder taps each time. The reason is the transition. Two squats take a few seconds, then you go down into a plank for 12 taps, then back up for 2 more squats, and so on. Five trips to the floor and back per set, ten squats and sixty taps in total, with the getting up and down doing the rest. It is the plank shoulder tap treated as the main event, with the squats serving as the reset between blocks.

Full squats, hips back and thighs to parallel, both of them. Then hands to the floor, feet back, and a strict plank for the taps: hips level, 6 taps per hand. Stand up cleanly rather than crawling up. Keep the flow going; the card has no pauses written into it.

Two squats, twelve taps, five times over: a circuit where the walk to the floor is half the work.

Make it Harder: Make the 2 squats jump squats every time.

Make it Easier: Take 6 shoulder taps per block and go through the transitions slowly.

Day 54 is a full body circuit with the legs moving in three directions and the arms punching in two: 12 tap side lunges, 6 side-to-side lunges, 12 lunge step-ups, 12 punches and 12 overhead punches. Five moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Lunge step-ups are new.

A lunge step-up starts with a reverse lunge, back knee toward the floor, then drives up out of it and lifts that back knee high in front of you, standing on the front leg, before stepping back into the next lunge. Twelve total, 6 per leg. It turns the lunge into a balance exercise at the top and a power exercise on the way up. Before it, tap side lunges and side-to-side lunges work the legs across, and after it the two kinds of punches give the legs a rest while the shoulders finish.

Tap side lunges: sit into one hip, tap the floor with the opposite hand, stand. Side-to-side lunges stay low as they shift. In the lunge step-up, push through the front heel and bring the knee up to hip height with the chest tall, pausing for a moment on one leg before stepping back. Punches with the shoulder turning in; overhead punches reaching for the ceiling.

Sideways, backward, then up onto one leg: the lunge learns a new trick before the punches arrive.

Make it Harder: Add a small hop on the standing leg at the top of every lunge step-up.

Make it Easier: Cut the lunge step-ups to 6 and skip the knee drive, doing plain reverse lunges instead.

Day 55 is a balance and coordination day drawn as a star. Balance on one leg and tap the other foot to the five points of the star in order, 1 to 5, and keep going around: 3 minutes on the right leg moving clockwise, then 3 minutes on the left leg moving counterclockwise, 6 minutes in total. Use the timer; there is no rep count.

The five points are drawn around you, in front, to the sides and behind, so the tapping foot has to reach in every direction while the standing leg holds you up. Three minutes on one foot is a long time, and the corrections the standing ankle and hip make with every reach are the exercise. Changing the direction of travel on the second leg means both sides get the same pattern mirrored. Treat it as a lighter day: the pace is steady, not fast.

Keep the standing knee soft and the hips level; the reaching foot taps lightly and comes back to the middle each time without taking weight. Keep the arms loose for balance and the eyes on a fixed point. If you lose balance, put the foot down, reset and continue the clock. Small, accurate taps beat big lunges toward the points.

Six minutes on one foot at a time, and every wobble is the work getting done.

Make it Harder: Balance days do not add load; if the star feels easy, close your eyes for the last 30 seconds of each leg instead.

Make it Easier: Keep one hand on something solid and do 2 minutes on each leg.

Day 56 is a cardio circuit in the list format with nothing on the floor: 12 high knees, 6 butt kicks, repeated five times for one set. Up to 2 minutes rest, 3, 5 or 7 sets by level. The two moves are both running on the spot; one lifts the knees, the other lifts the heels.

High knees drive each knee to hip height, 12 meaning 6 per leg. Butt kicks flick each heel up toward the glutes, 6 meaning 3 per leg. Neither takes you off your feet or onto the floor, so this card is pure pace: sixty high knees and thirty butt kicks per set with no transition to hide in. The change from knees to heels every few seconds keeps the hamstrings and hip flexors trading the load.

Stay on the balls of the feet and pump the arms on both. On high knees, keep the chest up rather than leaning back. On butt kicks, the knees point down while the heels come up; the thigh does not swing forward. Keep the rhythm constant from one block to the next.

Knees up, heels up, ninety reps a set, and not a single reason to stop moving.

Make it Harder: Take the butt kicks to 12 per round to match the high knees.

Make it Easier: March the high knees and keep the butt kicks at 6.

Day 57 is an abs card with two holds among the reps: 12 flutter kicks, a 10-count high crunch hold, 6 sit-ups, 12 sitting twists and a 10-count hollow hold. Five in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Both holds are new to the program.

The high crunch hold lies on the back with the knees bent and the feet on the floor, then lifts the shoulders and reaches both arms straight up toward the ceiling, and stays there for the count. The hollow hold lies flat with the arms reaching overhead and the legs straight, then lifts both ends off the floor, hands and feet hovering, with the lower back pressed down, and holds. One works the upper abs in a short crunch, the other works the whole front of the body as one long line. Flutter kicks, sit-ups and sitting twists fill in between.

In the high crunch hold, lift the shoulder blades, not the chin, and keep the reach vertical. In the hollow hold, the lower back must stay in contact with the floor; if it lifts, raise the legs or bring the arms forward until it does. Kicks low, sit-ups rolled, twists tall. Ten slow counts on each hold.

Two holds, one short and one long, and the middle finds out which one it prefers.

Make it Harder: Double both holds to a 20-count.

Make it Easier: Bend the knees in the hollow hold and cut the sitting twists to 8.

Day 58 is a challenge day for the calves: calf raises, 80 reps for Level I, 100 for Level II, 120 for Level III, split into manageable sets. No timer, no set count. Both feet together, hands behind the back as drawn, so each rep counts both calves at once.

Calves recover fast and get used to high numbers, which is why the total is big. A calf raise rises onto the balls of the feet as high as the ankles allow and lowers all the way down; the top and the bottom are both part of the rep. The muscles are small, so the challenge is less about strength than about not cutting the range as the reps pile up. Sets of 20 or 25 with a short shake-out in between will get through the number without the form fading.

Stand tall, weight spread across the balls of both feet, and rise straight up rather than rolling onto the outside of the foot. Pause for a moment at the top, then lower under control until the heels touch. Keep the knees straight but not locked. Hold a wall for balance if you need it, but do not lean on it.

The smallest muscles on the card get the biggest number, and they can take it.

Make it Harder: Do the total one leg at a time, half the reps on each.

Make it Easier: Split the total into sets of ten and rest as long as you like between them.

Day 59 is the upper body circuit at 12, and four of the six moves have appeared before somewhere: 12 bicep extensions, 12 W-extensions, 12 elbow clicks, 12 arm extensions, 12 arm scissors and 12 scissor chops. Six moves, one set, up to 2 minutes rest, 3, 5 or 7 sets by level. W-extensions and arm extensions are the two to learn.

W-extensions start with both arms straight up overhead, then pull the elbows down and back until the arms form a W with the fists at shoulder height and the shoulder blades squeezed together, then press back up. Arm extensions start with the arms straight out to the sides at shoulder height and bring them forward until they point straight ahead, then open them wide again. Both keep the arms at or above shoulder height and both count one rep for both arms moving together. Bicep extensions, elbow clicks, arm scissors and scissor chops fill out the rest.

On W-extensions, drive the elbows down hard and feel the squeeze between the shoulder blades at the bottom. On arm extensions, keep the arms straight and level as they swing forward and open. Elbow clicks with the forearms vertical and the elbows meeting. Scissors and chops level, alternating the top arm. Tense the arms throughout; you are your own resistance.

Seventy-two arm reps, six directions, and every one of them costs a little more than the last.

Make it Harder: Run every rep at a 3-count out and a 3-count back with the fists clenched.

Make it Easier: Cut all six exercises to 8 reps and let the arms hang for a few seconds between them.

Day 60 closes the second month with a lower back sequence, a lighter day done once through. Five moves in order: 12 knee rolls, 12 bridges, a 10-count stretch and hold, 12 reverse flutter kicks and a 10-count stretch hold to finish. No sets, no rest timer, one pass.

Knee rolls lie on the back with the knees bent and the arms out wide, then lower both knees together to one side and roll them across to the other, 12 in total, 6 per side. Bridges lift the hips off the floor with the feet flat and lower them. The first hold lies face down with the hands beside the head and lifts the chest off the floor, a back extension held rather than repped. Reverse flutter kicks stay face down and lift the straight legs alternately, 12 total, 6 per leg. The last hold is a kneeling fold with the arms stretched forward and the forehead toward the floor. Mobility, then strength, then stretch: the lower back gets all three.

Roll the knees slowly and keep both shoulders on the floor. Squeeze the glutes at the top of every bridge rather than arching the lower back. In the extension hold, lift with the back muscles and keep the neck long, looking at the floor. Reverse flutter kicks are small and controlled, the hips staying down. Sink into the kneeling fold and breathe for the full count.

Sixty days of squats, planks and jumps; today the lower back gets thanked for all of it.

Make it Harder: A back day is not one to load; if you want more from it, go through the five moves a second time at the same easy pace.

Make it Easier: Do 6 of each rep exercise and hold each stretch for a 5-count.

Day 61 opens the final month, and the count steps up again: the base number is now 14. The full body circuit is 14 hero squats, 14 overhead punches, 14 punches, 14 squat hold punches, 14 shoulder taps and a 10-count plank hold. Six moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. It is the Day 41 card with two more reps on everything, plank shoulder taps in place of the side leg raises and a plank hold added at the end.

Every exercise here has been on a card before, which is the point: the third month is not about learning, it is about doing more of what you know. Hero squats reach and fold, 14 times. The two kinds of punches and the squat hold punches run the arms through 42 punches while the legs work underneath. Plank shoulder taps, 7 per hand, lead into a 10-count full plank hold so the set ends on the shoulders staying still after all that moving.

Full reach at the top and heels flat at the bottom of every hero squat. Overhead punches straight up, regular punches straight out, both with the shoulder turning in. Keep the squat where it is during the squat hold punches. Shoulder taps with the hips level, then hold the plank in one line for the count without letting the hips sink.

Month three starts where month two left off, plus two reps and a plank hold, and that is how progress looks here.

Make it Harder: Stretch the plank hold at the end to a 30-count.

Make it Easier: Run 10 reps on everything and keep the 10-count plank hold.

Day 62 is a cardio circuit in the list format: 14 jumping jacks, 1 plank walk-out, repeated five times for one set. Up to 2 minutes rest, 3, 5 or 7 sets by level. The floor trip this month is a walk-out rather than a jump, which is slower and, for the shoulders, harder.

Fourteen jumping jacks, then fold forward, put the hands on the floor, walk them out to a full plank, walk them back and stand up. That is 1 plank walk-out, and it takes longer than a plank jack or a jump-in because there is no jumping to shorten it. Seventy jumping jacks per set keep the pulse high; five walk-outs put the shoulders under load at the moment the arms would rather rest. The pairing works because the two halves cost different things.

Full jumping jacks with the hands meeting overhead. Walk the hands out with control and pause for a moment in a straight plank before walking back; do not rush the plank away. Keep the knees soft in the fold and stand up tall each time. Move straight into the next block of jacks.

Seventy jacks and five slow walks to the floor and back: the pace is in the jacks, the price is in the walk.

Make it Harder: Do 2 walk-outs each round instead of 1.

Make it Easier: Take the walk-outs to a knee-down plank and cut the jacks to 10 per block.

Day 63 is an abs day at the third-month count: 8 sit-up punches, 14 sitting punches, 14 scissors, 8 circles and 14 scissors again. Five in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. It is the Day 42 card with the numbers raised and the leg work reshuffled: scissors on either side of a block of leg circles.

Sit-up punches roll all the way up and throw one punch at the top, 8 total, alternating arms. Sitting punches stay at the top with the feet lifted and throw 14. Then scissors, 14 meaning 7 per leg, then 8 leg circles with both straight legs together, 4 in each direction, then 14 more scissors. The double block of scissors around the circles is the design: the legs never get to rest, so the circles land on a middle that is already working.

Sit fully up before the punch and rotate through the shoulder. Keep the chest tall and the feet off the floor for all 14 sitting punches. Scissors low and quick with the lower back pressed down. Make the circles small enough that the back stays on the floor; if it lifts, the circle is too big.

Punch, scissor, circle, scissor: the abs get the boxing card at the third-month numbers.

Make it Harder: Slow the leg circles to a 4-count each and keep the scissors at 14.

Make it Easier: Skip the second block of scissors and bend the knees for the circles.

Day 64 is the second endurance day, and a fifth hold has joined the four from Day 19: 2 minutes each of a squat hold, a calf raise hold, a raised arms hold, an elbow plank hold and a superman stretch hold. That is 10 minutes of holding in total. As before, split into manageable sets if and when necessary, meaning each 2 minutes can be broken up if it must be, but the total per position is the target.

The calf raise hold is the new one: rise onto the balls of both feet, hands behind the back as drawn, and stay up there for 2 minutes. The calves are used to reps, not stillness, and two minutes on the toes is a different kind of tired. Around it, the squat hold parks the legs at parallel, the raised arms hold keeps both arms straight out in front, the elbow plank holds the trunk in one line and the superman lifts the arms and legs off the floor face down. Ten minutes, five regions, no repetitions.

Set a timer for each hold. Weight in the heels and chest up in the squat. Rise fully on the calf raise hold and keep the ankles steady; a wall touch for balance is fine. Arms level with the shoulders, not the eyes. Plank hips neither high nor low. Superman with the neck long and the gaze at the floor. When a hold breaks, rest briefly and restart the timer from where you stopped.

Ten minutes of holding, and the calves find out that not moving is also an exercise.

Make it Harder: Do all five holds unbroken with no more than 30 seconds between them.

Make it Easier: Break each hold into four 30-second pieces and rest between them.

Day 65 is a lighter day called an energy boost: five standing moves, 14 reps each, one pass through. Arm raises, chest expansions, half jacks, side bends and forward bends. No sets, no rest timer, 70 reps in total, all done standing and none of them hard.

This is a wake-up sequence rather than a workout. Arm raises lift both straight arms from the sides to overhead and lower them. Chest expansions sweep the arms from wide to crossed in front of the chest and back, squeezing the shoulder blades on the way out. Half jacks jump the feet apart and together with the arms staying down, a jumping jack without the arms. Side bends reach one arm down the side of the leg and back up, 14 total, 7 per side. Forward bends fold from the hips with the hands behind the head and stand back up. Shoulders, chest, legs, waist, back: five directions in five minutes.

Keep the arms straight on the raises and the shoulders down. Alternate which arm crosses on top in the chest expansions. Land the half jacks softly. Bend directly sideways on the side bends without twisting or leaning forward. In the forward bend, hinge from the hips with the back flat and the knees soft, and rise by squeezing the glutes.

Easy on purpose: seventy reps to switch the body on, and that is the whole job.

Make it Harder: Not today; this card is fuel, not load, and if it feels like too little, run the five moves through a second time at the same easy pace.

Make it Easier: Do 8 reps of each and step the half jacks instead of jumping.

Day 66 is a challenge day with the biggest total in the program so far: bridges, 100 reps for Level I, 120 for Level II, 140 for Level III, split into manageable sets. No timer, no set count. Lie on the back with the knees bent, feet flat and arms overhead on the floor as drawn, lift the hips, lower them, repeat until the number is done.

A bridge is a small movement for a big muscle, which is why a hundred is reasonable and a hundred and forty is possible. The glutes lift the hips until the body is straight from the knees to the shoulders, then lower them, and each rep takes a second or two. The challenge is in the accumulation: by the eightieth, the glutes have been working for minutes, and the temptation is to lift with the lower back instead. Sets of 20 to 25 with a short rest will get you there with the glutes still doing the lifting.

Drive through the heels and squeeze the glutes at the top; the hips come up until the thighs and torso form one line, no higher. Lower under control without bouncing off the floor. Keep the arms relaxed overhead and the neck long. If the hamstrings cramp, walk the feet a little closer to the hips and continue.

A hundred and forty bridges at the top level, and the glutes finally get a whole day to themselves.

Make it Harder: Do the second half of the total one leg at a time, alternating legs every 10 reps.

Make it Easier: Work in sets of ten and keep the feet a little wider for stability.

Day 67 is a full body circuit with the Day 31 leg work at the new count, and plank rotations and punches in place of the walk-outs: 14 reverse lunges, 8 side-to-side lunges, 8 kneeling squats, 14 shoulder taps, 8 plank rotations and 14 punches. Six moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level.

Three leg moves, two plank moves, then punches to finish. Reverse lunges at 14 means 7 per leg. Side-to-side lunges shift low across 8 times, 4 per side. Kneeling squats sit back to the heels and rise, 8 times, arms reaching. Then the plank: shoulder taps, 7 per hand, and rotations, 4 per side, turning the whole body toward the ceiling and back. Punches close the set with 14, the only exercise on the card that lets the legs and shoulders both rest a little.

Reverse lunges with the back knee to a hover and the front shin upright. Side-to-side lunges staying low as they shift. Kneeling squats with the hips driving forward on the way up. Shoulder taps hips still; rotations with the supporting arm straight and the top hand reaching high. Punches with the shoulder turning in, fists back to the chin.

Legs, plank, fists: the third-month version of a full body day, and every part gets its turn.

Make it Harder: Pause at the top of every plank rotation for a 2-count with the arm fully extended.

Make it Easier: Cut the reverse lunges and shoulder taps to 8 and leave the rest as printed.

Day 68 is a 2-minute plank, done as six 20-second pieces without rest: 20 seconds of full plank, 20 seconds of elbow plank, 20 seconds of raised leg plank with 10 seconds on each leg, 20 seconds of side plank with 10 seconds on each side, then 20 seconds of full plank and 20 seconds of elbow plank again. One pass, 2 minutes, done. Use the timer on the page; it is set for six intervals.

Two minutes in one plank would be a test of stubbornness. Two minutes across six positions is a test of control, because every change asks the body to find a new line without the hips sagging in between. The full plank is on the hands; the elbow plank on the forearms; the raised leg plank is an elbow plank with one foot lifted; the side plank rests on one forearm with the hips lifted and the top hand on the hip. Then the first two come back to finish. The changes are where the work is.

Move between positions without standing up or resting the knees. Keep the hips level in the raised leg plank and swap legs at 10 seconds. In the side plank, stack the feet or stagger them and lift the hips into a straight line, swapping sides at 10 seconds. Breathe throughout; two minutes is too long to hold your breath.

Six planks, two minutes, zero rest, and the transitions are the exercise.

Make it Harder: Run the full 2-minute sequence twice with 60 seconds rest between.

Make it Easier: Do the raised leg plank and side plank from the knees and keep the timing as printed.

Day 69 is high intensity interval training with punches in the middle: 20 seconds of high knees, 20 seconds of punches and 20 seconds of jumping jacks, back to back for one 60-second set. Rest 60 seconds, then 3, 5 or 7 sets by level. All standing, no floor.

Punches are the interval that looks like a rest and is not one. Twenty seconds of alternating straight punches at speed keeps the shoulders working and the heart rate up while the legs get a moment, and then the jumping jacks take everything back up together. High knees open at running pace. It is a simpler set than the jack-heavy ones, and the temptation is to coast through the punches; do not.

High knees with the knees to hip height and the arms driving. Punch fast and full, turning the shoulder into each one and bringing the fist back to the chin, bouncing lightly on the feet. Jumping jacks at full range with soft landings. Keep every interval at a pace you can hold for its whole 20 seconds.

Run, punch, jump, rest, repeat: the intervals do not care that it is Day 69.

Make it Harder: Shorten the rest to 30 seconds and keep the intervals at 20.

Make it Easier: Keep every interval at 20 seconds but march instead of run and step instead of jump.

Day 70 is a tendons and core card with its own structure, printed on every exercise: 14 side bridges x 2 sets, 14 side leg raises x 2 sets, 14 leg raises x 2 sets and 14 bridges x 2 sets. For the first three, the two sets are one per side with no rest between them, so 14 side bridges on the left straight into 14 on the right, and so on. The bridges are 2 sets of 14 with 20 seconds rest between them. Work through each exercise completely before moving to the next.

Because the sides are split into sets, the 14 here is per side, not a total, which is different from every circuit card. Side bridges lift the hips from a side-lying position on the forearm. Side leg raises lie on the side and lift the top straight leg, the Day 15 move without the rest of the sequence around it. Leg raises sit back on the hands with one leg straight and lift it, the Day 25 move, 14 per leg. Bridges finish with both feet on the floor and the hips driving up. Forty-two reps per side and 28 bridges, and the only rest anywhere is 20 seconds in the middle of the last exercise.

Side bridges in a straight line from head to feet, lifting with the hip. Side leg raises with the toes forward and the body still. Seated leg raises with the chest open and the working leg straight, the foot never touching down within a set. Bridges with the glutes doing the lifting and the ribs down. Switch sides quickly; the absence of rest is the tendon work.

Four exercises, two sets each, sides done one at a time: a quiet card that adds up to a lot of hip.

Make it Harder: Add a 10-count side bridge hold at the end of each side bridge set.

Make it Easier: Do 8 per side each set and take a short breather when changing sides.

Day 71 is a full body circuit in the repeated-pair shape: 14 jumping jacks, 14 climbers, 4 plank leg raises, then 14 jumping jacks, 14 shoulder taps and 4 plank arm raises. Six moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Both halves start standing and end in a plank.

The two blocks share the jacks and differ in the plank. The first pairs climbers, 7 per leg, with 4 plank leg raises, 2 per leg, so the hips go from moving fast to lifting slowly. The second pairs shoulder taps, 7 per hand, with 4 plank arm raises, 2 per arm, so the shoulders do the same thing. Only 4 of each raise, but they come at the end of 14 reps of plank work, which is when the hips least want to stay level. The numbers are small; the position they land in is not.

Full jumping jacks. Climbers with the hips down and the knee driving in. Plank leg raises lift a straight leg a few inches without tilting the hips. Shoulder taps strict. Plank arm raises reach a straight arm forward to shoulder height with the body square to the floor. All the plank work in a straight line from head to heels.

Jacks into planks, twice, and four slow raises at the end of each block to keep the hips honest.

Make it Harder: Take both kinds of plank raise to 8 and hold the top of each for a 2-count.

Make it Easier: Cut the climbers to 8 and take the plank raises at half the range.

Day 72 is a full body circuit that ends face down: 14 squats, 14 punches, 14 lunges, 14 shoulder taps, 14 W-extensions and 14 prone reverse fly. Six moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. The first four are the Day 1 card at the new count; the last two are on the floor and both are new in this position.

W-extensions here are done lying face down: arms stretched overhead and lifted off the floor, then pulled down and back into a W shape with the elbows bent, then extended again, 14 times with the hands never touching down. Prone reverse fly stays face down with the arms straight out to the sides, lifting them off the floor and lowering, 14 times. Both work the upper back and the rear of the shoulders, the muscles that punches and planks leave behind, and putting them after four standing and plank moves means the shoulders finish the set from the opposite direction.

Squats to parallel, punches with the shoulder turning, lunges with the back knee to a hover, 7 per leg. Shoulder taps with the hips still. In both prone moves, keep the neck long and the forehead pointing at the floor, lift the arms with the muscles between the shoulder blades, and keep the hands hovering for the whole set.

The Day 1 card, grown up, with a pair of floor moves to balance out ten weeks of punching.

Make it Harder: Hold the arms at the top of every W-extension and reverse fly for a 2-count before lowering.

Make it Easier: Cut the two prone moves to 8 and rest the hands on the floor between reps.

Day 73 is an abs day with the third-month numbers: 8 leg raises, 14 sitting twists, 14 flutter kicks, 8 heel taps and 14 hundreds. Five in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Nothing new; the card mixes moves from four earlier abs days into one.

Leg raises lift both straight legs to vertical and lower them, 8 times. Sitting twists lean back with the feet lifted and turn side to side, 7 per side. Flutter kicks 7 per leg. Heel taps reach each hand toward the same-side heel with the shoulders lifted, 4 per side. Hundreds finish with the knees at a right angle, shoulders off the floor and both arms pumping, 14 pumps. Lower abs, obliques, lower abs again, obliques again, then the whole front of the body at once.

Lower the legs slowly on the raises and stop before the heels touch. Turn from the waist on the twists with the chest tall. Flutter kicks low with the back pressed down. Heel taps with the shoulder blades off the floor throughout. Hundreds with quick small pumps and steady breathing, the head and shoulders held up for all 14.

Five moves, three months of practice behind them, and no excuses left for a sagging lower back.

Make it Harder: Take the leg raises to 14 to match the rest of the card.

Make it Easier: Cut the hundreds to 8 pumps and bend the knees for the leg raises and flutter kicks.

Day 74 is a cardio circuit without the list format: six moves in a row, all at 14. Jumping jacks, high knees, knee-to-elbow, jumping jacks, high knees and twists. All six is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Everything is standing and the sixth move is new.

Twists stand with the hands on the hips and turn the upper body from side to side, 14 total, 7 per side, a fast rotation of the trunk over fixed hips. It is the only exercise on the card that is not a jump or a run, and it arrives last so that the twist happens on a pulse that is already up. Before it, the pattern runs jacks, high knees, knee-to-elbow, jacks, high knees: 84 reps a set with no floor and no rest inside the set.

Full jumping jacks, high knees to hip height with the arms pumping, knee-to-elbow with the elbows wide and the knee coming up to meet them, 7 per side. On the twists, keep the feet planted and the hips facing forward while the shoulders turn; the movement is quick and the range is moderate. Flow from one block to the next.

Eighty-four reps a set, all standing, and the twist at the end finds the middle when it is tired.

Make it Harder: Take the knee-to-elbow and twists to 20 each.

Make it Easier: Cut both blocks of jumping jacks to 8 and take the twists slowly.

Day 75 is a neck mobility day, and it is the lightest card in the program. Five movements, each repeated 14 times in total, which is 7 each side: back and forth tilts, side-to-side tilts, neck rotations, side-to-side head turns and shrugs. One pass, no sets, no timer. Standing or sitting, both work.

Back and forth tilts look up toward the ceiling and down toward the chest. Side-to-side tilts take the ear toward each shoulder. Neck rotations roll the head slowly in a circle, 7 in each direction. Side-to-side head turns look over each shoulder. Shrugs lift both shoulders toward the ears and lower them, 14 times. Ten weeks of planks, punches and crunches load the neck in ways that never show up on a card, and this is the day that undoes it.

Move slowly and stop at the end of comfortable range; nothing here is pushed. Keep the shoulders down and still during the tilts, turns and rotations so the movement comes from the neck alone. Roll the rotations smoothly rather than in jerks. Let the shrugs fully release at the bottom of every rep.

A part of the body the circuits ignore gets a few quiet minutes, seventy small movements at a time.

Make it Harder: The neck is not somewhere to add load; if you want more, slow each movement to a 3-count in each direction.

Make it Easier: Do 8 of each and skip the rotations if they make you dizzy.

Day 76 is a full body circuit with three kinds of lunge: 14 reverse lunges, 14 split lunges, 8 side-to-side lunges, 14 calf raises, 14 punches and 14 shoulder taps. Six moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Split lunges are new.

A split lunge stands in a lunge stance, one foot forward and one back, and lowers the back knee toward the floor and rises again without moving the feet. Because the feet stay put, do 7 with one leg in front, then switch and do 7 with the other. Reverse lunges before it step the foot back each rep, 7 per leg; side-to-side lunges after it shift low across, 4 per side. Calf raises at 14, then punches and plank shoulder taps to finish. Thirty-six lunges a set is the story of the card.

Reverse lunges with the front shin vertical. Split lunges straight down and straight up, the front knee tracking over the ankle and the torso upright; the front heel stays flat. Side-to-side lunges at the same low height as they shift. Calf raises to full height. Punches with the shoulder turning; shoulder taps with the hips still.

Thirty-six lunges a set, backward, in place and sideways, and the calf raises are the rest.

Make it Harder: Jump to switch legs at the top of the last 4 split lunges on each side.

Make it Easier: Cut the split lunges to 8 and hold a wall for balance during them.

Day 77 is an abs day with one new move up front: 8 knee crunches, 14 flutter kicks, 8 leg raises, 8 circles and 14 scissors. Five in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level.

A knee crunch lies on the back with the arms stretched overhead, then folds in the middle: the knees pull in toward the chest while the shoulders lift and the hands reach toward the shins, then everything extends back out to hovering. Eight of them. It is a sit-up and a reverse crunch at once, working both ends of the abs toward the middle. Flutter kicks, leg raises, circles, 4 each way, and scissors then keep the legs hovering for the rest of the set.

In the knee crunch, bring the knees and shoulders toward each other at the same time and extend back out without letting the heels or the hands touch the floor. Flutter kicks and scissors low and quick. Leg raises slow on the way down. Circles small enough that the back stays flat. The lower back stays pressed into the floor for all five.

Fold in, reach out, and then the legs hover for 44 more reps: the abs day with no floor time for the heels.

Make it Harder: Hold the folded position of every knee crunch for a 2-count before extending.

Make it Easier: Let the feet rest on the floor between knee crunches and bend the knees for the circles.

Day 78 is a cardio circuit in the list format with a hop: 14 high knees, 2 side-to-side hops, repeated five times for one set. Up to 2 minutes rest, 3, 5 or 7 sets by level. All standing, and the hops are done on one leg.

Side-to-side hops stand on one leg with the other knee lifted and the arms out for balance, then hop sideways and back, one hop each way. That is the 2 on the card. It sounds like nothing after 14 high knees, but landing a sideways hop on one foot with the pulse up is a coordination test as much as a cardio one. Alternate the hopping leg from round to round, and keep the high knees at running pace in between.

High knees with the knees driving to hip height. For the hops, land softly on the ball of the foot with the knee bent, stick the landing for a moment, then hop back. Keep the arms out and the eyes forward. Do not let the lifted knee touch down until the pair of hops is done.

Seventy high knees and ten one-legged hops per set, and the hops are where the balance gets tested.

Make it Harder: Do 4 hops per round, two each way, and stay on the same leg for the full set.

Make it Easier: Step sideways and back instead of hopping and cut the high knees to 10.

Day 79 is the upper body circuit at 14, and it is the Day 4 card with the first two moves swapped out: 14 bicep extensions, 14 side shoulder taps, a 10-count hold with the arms out to the sides, 14 arm scissors, 14 scissor chops and a 10-count hold with the arms straight out in front. Six moves, one set, up to 2 minutes rest, 3, 5 or 7 sets by level.

Bicep extensions curl and extend under your own tension. Side shoulder taps touch the shoulders and reach out to the sides at shoulder height, and then the first hold keeps the arms out there for the count. Arm scissors and scissor chops cross and sweep, then the second hold parks the arms straight ahead. Fifty-six reps and two holds with the arms never going below the shoulders, four more reps on each move than the week-one version, and no more rest for the shoulders than there was then.

Tense the arms through both directions of the bicep extension. Reach fully on the side shoulder taps. In the first hold, arms level and palms down, fingers reaching away. Scissors and chops with the arms straight and alternating on top. In the second hold, arms parallel and level with the shoulders, no sinking as the count runs.

The Day 4 shape at third-month numbers, and the shoulders remember every rep of the first version.

Make it Harder: Take both holds to a 20-count with the fists clenched.

Make it Easier: Cut the four rep exercises to 8 and keep both holds at 10.

Day 80 is a stretching day, standing and kneeling, with a 10-count on each side for every position before moving on. Six positions, one pass, no sets. Where a stretch has no side, hold it once.

Position 1 is a standing quad stretch, one foot held behind you. Position 2 clasps the hands behind the back with the arms straight, opening the chest. Position 3 keeps the hands clasped behind and lets the head fall forward, adding the back of the neck to the stretch. Position 4 is a kneeling lunge with the hands on the front knee. Position 5 is a side lunge with one leg straight, the hands together in front. Position 6 is a wide straddle stance with the hands on the thighs, shifting the weight to one side.

Knees together and standing tall in the quad stretch. Lift the clasped hands slightly in the chest opener and keep the shoulders back; when the head hangs, let its weight do the work rather than pulling. Hips forward gently in the kneeling lunge. Sit into the side lunge with the straight leg's foot flat. Chest up and feet turned slightly out in the straddle. Slow counts throughout.

Eighty days in, and the front of the hips and the back of the neck get their ten counts each.

Make it Harder: Stretching is the one place the program says no to harder; take every count to 20 and call that more.

Make it Easier: Shorten every hold to a 5-count and keep a hand on a wall for the standing stretches.

Day 81 is a full body circuit that alternates two moves with two others: 14 jumping jacks, 4 split jacks, 14 jumping jacks, then 14 shoulder taps, 4 plank jump-ins and 14 shoulder taps. Six moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. The first half is standing, the second half is in a plank.

The structure is a sandwich twice over: jacks around split jacks, then shoulder taps around plank jump-ins. The 4 split jacks, 2 per leg, and the 4 plank jump-ins are short bursts of a harder movement inside longer blocks of an easier one, so the pulse and the shoulders never get a real break. Twenty-eight jumping jacks and 28 shoulder taps per set, with eight harder reps tucked in between them.

Full jumping jacks, soft landings. Split jacks with the switch in the air and the front knee over the ankle. Shoulder taps with the hips level, 7 per hand each block. Plank jump-ins landing the feet close to the hands and jumping straight back to a clean plank. Go straight from the second block of jacks to the floor and stay there for the rest of the set.

Two easy moves wrapped around two hard ones, twice, and the set never gives you a moment to settle.

Make it Harder: Take the split jacks and plank jump-ins to 8 each.

Make it Easier: Run each block at 8 and step the jump-ins one foot at a time.

Day 82 is called Bouncer, and the whole card is built on a boxer's bounce: 14 bounces, 8 bounce plus squat, 14 bounce plus punch, 14 bounces, 8 bounce plus squat and 14 bounce plus overhead punch. Six moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Everything is done from a fighting stance.

A bounce is the light hop on the balls of the feet a boxer keeps going between punches; 14 of them is 14 hops, guard up. Bounce plus squat sinks into a full squat on every bounce and springs back up, 8 times. Bounce plus punch throws a straight punch on each bounce, 14 total, alternating arms. Then the pattern repeats with overhead punches in place of straight ones. The bounce never stops within the set, so the calves and ankles are working the whole time while the squats and punches change what sits on top of them.

Stay on the balls of the feet with the knees soft and the fists up. On bounce plus squat, sink to parallel and use the bounce to spring out of it. On the punches, land the bounce and throw in one motion, turning the shoulder into every one. Overhead punches reach straight up. Keep the rhythm steady through all six blocks.

Seventy-two bounces a set with squats and punches riding on top, and the feet never go quiet.

Make it Harder: Make every bounce a full jump with both feet clearing the floor.

Make it Easier: Turn the bounces into a light rock from foot to foot and cut both squat blocks to 4.

Day 83 is abs and core with four plank moves and nothing on the back: 8 up and down planks, 8 body saw, 14 plank arm raises and 14 side bridges. Four in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level.

Up and down planks move between the hands and the forearms, 8 trips, alternating the leading arm. Body saw rocks the elbow plank back and forward 8 times. Plank arm raises are done from the elbow plank, 7 per arm, reaching one arm forward with the hips level. Side bridges finish, 7 per side, lifting the hips from the forearm. Three of the four are on the forearms in a row, which is the reason the card has only four exercises; there is no rest in it for the shoulders until the set ends.

Hips still on the up and down planks with the feet a little wide. Body saw from the shoulders, plank rigid. In the arm raises, the hips do not tilt; reach only as far as they allow. Side bridges in one straight line, lifting with the hip and pausing at the top before lowering.

Four planks in a row, three of them on the forearms, and the middle holds the whole thing up.

Make it Harder: Run the body saw at 14 and the up and down planks at 10.

Make it Easier: Cut the plank arm raises and side bridges to 8 and take the up and down planks from your knees.

Day 84 is the last interval session of the program: 20 seconds of half jacks, 20 seconds of jumping jacks and 20 seconds of squat jacks, back to back for one 60-second set. Rest 60 seconds, then 3, 5 or 7 sets by level. Three jacks that step up in cost from one interval to the next.

Half jacks jump the feet apart and together with the arms staying down, the legs-only version from the energy boost day. Jumping jacks add the arms overhead. Squat jacks add the squat: feet wide into a squat with the arms up, feet together standing with the arms down. Each interval asks for a little more than the last, so the set is built to finish hard. Seven HIIT days into the program, the 60-second rest is the same as it was on Day 7; what has changed is what you fit into the 60 seconds before it.

Half jacks quick and light. Jumping jacks at full range with the hands meeting overhead. Squat jacks landing wide with the knees over the toes and sinking to a real squat every rep. Keep the pace up for the whole 20 seconds of each interval rather than sprinting the first 10.

Half, full, squat: the last set of intervals climbs all the way up, and then it is done.

Make it Harder: Rest 30 seconds instead of 60 and keep the intervals at 20 seconds.

Make it Easier: Step the half jacks and jumping jacks, and turn the squat jacks into plain squats.

Day 85 is a spine stability card with its own set structure, printed under every exercise: 5 sets of 14 with 30 seconds rest, for each of four moves. This is not a circuit. Do all 5 sets of leg swings, then all 5 sets of alternating arm and leg raises, then all 5 sets of deadbugs, then all 5 sets of bridges, resting 30 seconds after each set. Use the timer for the rests.

Leg swings are done on all fours: one straight leg extended behind you, swinging up and lowering, 7 per leg within a set. Alternating arm and leg raises stay on all fours and reach the opposite arm and leg out at the same time, then switch, 7 per side. Deadbugs lie on the back with the arms and knees up, then lower one arm overhead and the opposite leg toward the floor, return, and switch, 7 per side. Bridges lift the hips from the floor, 14 times. Every one of the four asks the spine to stay still while the limbs move, which is what stability means, and 5 sets of each makes 280 reps of it.

On all fours, hands under the shoulders and knees under the hips, back flat. Swing the leg without letting the hips tilt. In the arm and leg raises, reach long in both directions and keep the trunk level. In the deadbug, press the lower back into the floor and lower the limbs only as far as it stays there. Bridges with the glutes, not the lower back.

Twenty sets, 280 reps and the spine never moves; that is the whole idea, and it is harder than it sounds.

Make it Harder: Slow the deadbugs to a 3-count each way and leave the other three as printed.

Make it Easier: Do 3 sets of each exercise and take 45 seconds rest.

Day 86 is the last upper body circuit of the program, at 14: 14 shoulder taps, 14 side shoulder taps, 14 arm circles, 14 chest expansions, 14 arm extensions and 14 scissors. Six moves, one set, up to 2 minutes rest, 3, 5 or 7 sets by level. All six have appeared before; the scissors here are the arm version.

Standing shoulder taps reach up, side shoulder taps reach out, arm circles turn 7 each way with the arms held level, chest expansions sweep wide and cross, arm extensions swing from the sides to the front and back, and arm scissors cross and uncross in front of the chest. Eighty-four arm reps a set with the hands never below shoulder height, the same idea as Day 4 with 40 percent more of it. No new movements; the third month is about volume.

Reach fully on both kinds of tap. Small controlled circles. Chest expansions with a squeeze between the shoulder blades on the way out. Arm extensions straight and level. Scissors alternating the top arm. Shoulders down away from the ears for the whole set, and the arms tensed as if resisting something.

Eighty-four reps at shoulder height and the arms find out what twelve weeks of holding them up has built.

Make it Harder: Slow to a 3-count in each direction and keep both arms hard the whole set.

Make it Easier: Halve every exercise to 7 and let the arms hang for a breath between them.

Day 87 is a full body circuit that alternates jacks with planks three times: 14 jumping jacks, 14 shoulder taps, 14 jumping jacks, 14 plank rotations, 14 jumping jacks and 14 plank arm raises. Six moves in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. Three trips to the floor per set.

Forty-two jumping jacks a set keep the pulse high, and each block of 14 is followed by a different plank move: shoulder taps, 7 per hand; plank rotations, 7 per side, turning the whole body to the ceiling; plank arm raises, 7 per arm, from a full plank on the hands. The planks get harder in order, from a tap to a rotation to a reach, and each one arrives straight after a block of jumping.

Full jumping jacks with soft landings. Shoulder taps with the hips level. Rotations with the supporting arm straight and the feet stacked or staggered, the top hand reaching high. Arm raises with the body square to the floor and the hips still. Get down to and up from the plank cleanly each time.

Jacks, plank, jacks, plank, jacks, plank: the full body card that never lets the floor get far away.

Make it Harder: Hold a 10-count full plank after every plank move before standing for the next jacks.

Make it Easier: Cut every block to 8 and swap the plank rotations for shoulder taps.

Day 88 is the last abs day: 8 knee-to-elbow, 14 high crunches, 14 leg raises, a 10-count hold with the legs raised and 14 circles. Five in order is one set, up to 2 minutes rest, 3, 5 or 7 sets by level. The knee-to-elbow here is a seated version.

Seated knee-to-elbow leans back with the hands behind the head and the feet lifted, then brings one knee up while the opposite elbow comes across to meet it, alternating, 8 total, 4 per side. High crunches lift the shoulders toward raised, bent legs, 14 times. Leg raises lift both straight legs to vertical and lower, 14 times, then the hold keeps them hovering at about knee height for a 10-count, then 14 circles, 7 each way, with the legs still up. Forty-two reps and a hold with the legs never resting is the last thing the abs are asked for on the circuit cards.

Sit tall in the knee-to-elbow and twist from the trunk. High crunches lifting the shoulder blades, not the chin. Leg raises slow on the way down and stopped before the heels touch. Hold with the lower back pressed into the floor. Circles small and steady in both directions.

The last abs card lifts the legs and does not put them down until the circles are finished.

Make it Harder: Add a second 10-count hold after the circles with the legs still up.

Make it Easier: Soften the knees through the leg raises, the hold and the circles, and cut the circles to 8.

Day 89 is the last cardio circuit, in the list format: 14 high knees, 4 split jacks, repeated five times for one set. Up to 2 minutes rest, 3, 5 or 7 sets by level. All standing, both moves familiar, and a fitting last run before the final challenge.

High knees at running pace, 7 per leg, then 4 split jacks, 2 with each leg in front, then straight back to high knees. Seventy high knees and 20 split jacks per set. The split jacks are the interruption: they switch the legs front to back at the moment the high knees have them going up and down, which keeps the coordination working alongside the lungs. It is the same shape as Day 2, eighty-seven days later, with different numbers and a jump in place of a climber.

Knees to hip height and arms driving on the high knees. Split jacks with the switch in the air, soft landings and the front knee over the ankle. Move from one to the other without pausing; the whole list is one continuous set.

The last cardio circuit runs on the spot and jumps front to back, and then there is one card left.

Make it Harder: Double the split jacks to 8 per round.

Make it Easier: Turn the split jacks into step-throughs and keep the high knees at 14.

Day 90 is a challenge, and it is squats: 100 reps for Level I, 120 for Level II, 140 for Level III, split into manageable sets. No timer, no set count. The first exercise on Day 1 was 10 squats; the last exercise of the program is more than a hundred of them.

Squats are the most basic movement on any of these cards and the one that has shown up most often, in circuits, in holds with punches, in jacks and in reaches. Today they stand alone. Sets of 20 with a minute between them will get to 100 in 5 sets; sets of 25 or 30 will get to 140 in about the same number. The temptation on a last day is to race. Do not: a hundred and forty deep squats is a lot of squats, and the last ten should look the same as the first ten.

Feet about shoulder width, hips back and down, thighs to parallel or lower, chest up and heels flat. Arms reaching forward as drawn for balance. Drive up through the heels and stand tall at the top of every rep. Rest as long as you need between sets and keep the depth honest all the way to the end.

Ninety days ago the first card asked for 10 squats; this one asks for a hundred and more, and you can do them.

Make it Harder: Finish in sets of 50 with as little rest as you can manage.

Make it Easier: Sets of ten, with as much rest as you like between them.