If you are engage in a heavy exercise program you will need to stretch your muscles and improve your overall balance. As our muscles grow they get tight and loosing them helps in overall flexibility, balance and general performance. The last thing you want to do is be so tight you start to rip muscles even when doing basic movements. One sign of total fitness not only includes muscle tone but also the ability to use those muscles at different flexible ranges.
This program has some stretching and balance that can be helpful.