The interval of stretching after exercise depends on the athlete's heart rate. If the heart rate is too fast, it is recommended to relax for about 5 minutes before starting stretching. If the heart rate is relatively stable and there is no excessive fluctuation, you can start stretching exercise directly after exercise.

Stretching after exercise is mainly to prevent muscle congestion and stiffness under the stimulation of fitness training, which can promote muscle recovery, promote faster recovery of the body and improve the fitness effect.

Stretching after exercise can soften the coordination between muscle ligaments and joints, reduce the possibility of joint and muscle injuries and reduce the possibility of back problems. The stretching time is too short and the effect is not good. Stretching time is too long, and it is not good. Therefore, the stretching time should be controlled.

When stretching all parts, the stretching time should be 30-60 seconds. For the muscles in the back of thigh, it is generally considered that it is enough to keep stretching 15 seconds. For children and adolescents, 7- 10 seconds is generally appropriate. Under passive stretching, each group is usually 2-5 times, and the interval between groups is 15-30 seconds.