Stretching is a powerful part of any exercise program. Most aerobic and strength training programs inherently cause your muscles to contract and tighten.
Stretching after you exercise may help improve the range of motion about your joints and boost circulation.
As a general rule, stretch your major muscle groups after you exercise. In some studies, pre-athletic event stretching has been shown to decrease athletic performance.
Overall, however, stretching after exercise can help you to optimize your joint range of motion. If you don't exercise regularly, you may want to stretch a few times a week after a brief warm-up to maintain flexibility.
When you're stretching, keep it gentle. Breathe freely as you hold each stretch for around 30 seconds. Try not to hold your breath. Don't bounce or hold a painful stretch. Expect to feel tension while you're stretching. If you feel pain, you've gone too far.
Moving in sport- or activity-specific motion planes in gradually progressive speed (dynamic stretching) may be a helpful complement to static stretching and may help improve athletic performance