Many people just practice when they pick up dumbbells. After 20 lifts, they feel sore muscles, which makes it impossible for you to continue, but you can practice again, as long as you have a rest, and the pain will disappear. This happens to people who haven't run for a long time. I haven't run for a long time. They think the muscles in their legs are so sore that you don't want to run anymore. After a short rest, you will recover immediately. This situation is because lactic acid metabolized by temporary muscle ischemia during anaerobic exercise cannot be decomposed in time. Usually muscle activity stops, lactic acid is gradually decomposed and eliminated in the body, and this feeling of soreness disappears. The pain that can be felt immediately during this exercise is called acute muscle soreness. This kind of soreness is caused by the accumulation of chemicals in muscles, which can be quickly relieved by general massage, flapping and relaxing muscles.

This kind of acute muscle pain is not terrible, but delayed pain is the real pain, which will make you want to move. Delayed soreness usually appears after 8 hours, and it often takes 3 ~ 4 days or even 6 ~ 7 days to fully recover. This kind of pain is a stumbling block for beginners, making them so miserable that they don't even want to do exercise.

In fact, the cause of this soreness has not been completely solved. At present, the theory of muscle ultrastructure injury is relatively recognized. Theoretically speaking, many small muscle fibers are broken and injured during centrifugal contraction of muscles, and calcium ions gushed out from muscles cause inflammation and so on, leading to soreness.

But it is more likely that people who rarely participate in sports or participate in physical exercise for the first time will suddenly increase their exercise, which will easily lead to this kind of muscle pain. During exercise, muscle contraction needs energy. Generally, the energy of aerobic exercise comes from intracellular aerobic glucose metabolism, and the energy of anaerobic exercise comes from anaerobic glycolysis.

During aerobic exercise, glucose metabolism will generate water and carbon dioxide, which can be easily excreted through breathing and is harmless to human body. During anaerobic exercise, glycolysis will produce a large number of intermediate metabolites such as lactic acid, which can not be excreted through respiration, but can only be transported to the liver through blood and converted into glycogen. However, when too much lactic acid is produced, some lactic acid cannot be converted in time, forming lactic acid accumulation, which leads to muscle soreness.

For this kind of people, it is suggested to control the amount of exercise from small to large, and at the same time do warm-up exercises before exercise and stretching exercises after exercise. At the same time, it is not necessary to practice only one part for a long time, and various exercises should be carried out alternately.

I hope I can help you and adopt it.