Alternative Arm/Leg Raises challenge your core and help you develop better balance and stability. Breathe out as you extend opposite arm, opposite leg and breathe in as you relax. Keep your head up and looking forward to also work your neck and upper shoulder muscles. 

Works: abs and core, shoulders and calves.

Make it harder:

- Hold the post at full extension for a slow count of two each time. This locks the muscles into position and further depletes their stored fuel reserves forcing your body to work really hard.

- Try this exercise with wrist and ankle weights. It will hyperload your tendons and the muscle groups that are involved in this and force your core to work even harder.