When you're being chased you need to run. Your body requires strong muscles, powerful tendons, a cardiovascular system that will really get your heart pumping and your blood flowing to all the right muscle groups, plus you need your aerobic performance, your VO2 Max volume to be as near as optimal as possible. Chase does all of that, plus, since the difference between chasing and being chased is separated by a hair's breadth, it really prepares you for the times when you will need to be the one doing the chasing.
Extra Credit: 30 seconds rest between sets.
