Stretching can increase the flexibility of the body. Some people think that flexibility is only needed by gymnasts. In fact, people with stiff bodies and ligaments are easily injured in sports and daily life. Stretching can make the coordination between muscle ligaments and joints softer, reduce the possibility of joint and muscle injuries and reduce the possibility of back problems. In daily life, it often happens that when you are tired one day, you are particularly prone to backache the next day. This is because your body does not stretch in time. If people spend about 20 minutes stretching before doing a lot of exercise, they can relieve muscle soreness and keep their joints healthy. Stretching can actually be regarded as a kind of strength exercise, the most basic one. Its main purpose is to make the body feel soft and powerful. Stretching is not part of warm-up. Suitable for warm-up, because the muscles and body joints are already in a state of "itching". At this time, the stretching effect is the best and the possibility of injury is minimized. The most effective time for stretching should be after exercise, but it is best to stretch before and after exercise. You can divide 30 minutes or 20 minutes into two 10 minutes, so the exercise effect will be better. Basically, people who seldom exercise need to stretch about three times a week to keep their bodies flexible. It takes 30 minutes at a time. People who do a lot of exercise should stretch 7 days a week, 2-3 times a day, so that they don't need to repeat all kinds of stretching exercises for so long until their bodies feel flexible again. In addition, I believe that people who exercise regularly know that if you overstretch, it will bring some disadvantages to your body, that is, it is easy to get sore muscles, especially knees, and muscles are easy to strain. If you overstretch, the result is that you are more likely to get hurt. So don't overdo it. After mastering the stretching scale, supplemented by the correct exercise method, it will be beneficial to the body.