Potential benefits of a regular stretching program include an improved range of motion in your joints, improved flexibility, relief of stress-related muscle tension and increases in your blood circulation that can improve your rate of healing if you injure a muscle.
Since almost all aerobic and strength-training exercises involve flexion and contraction of your muscles, performance of a stretching routine before and after these exercises can help your body prepare for activity and might lower your risks for exercise-related injuries.