Do warm-up exercises before exercise, and then stretch muscles and joints to prevent muscles and joints from being injured when doing heavy movements.

Second, warm up after exercise, that is, there is no stretching of muscles and joints before doing a lot of exercise. There are two kinds of such situations. First, if the amount of exercise is small, such as just running and practicing abdominal muscles, it will generally not hurt muscles and joints. Secondly, if you do heavy movements as soon as you enter the gym, you should practice large muscle groups, such as bench press, hard pull, squat, barbell rowing and so on. If you are heavy, you'd better run and sweat first, and then stretch your joints and muscles, otherwise you will be easily injured.

Finally, warm-up before exercise, whether it is a large amount of exercise or a small amount of exercise, will reduce the damage to muscles and joints.

Warm up after exercise, this feeling is only suitable for a small amount of exercise.