Moderate exercise is good for health. It can reduce weight and reduce people's risk of various diseases, such as Alzheimer's disease. However, if you exercise excessively, it will lead to changes in heart rate, musculoskeletal changes, immune system changes, hormone changes and sleep changes, so a healthy body should exercise moderately.

First, the heart rate changes.

Athletes' hearts will change in molecular types, which will lead them to suffer from heart-related health problems. Sports physiology research has found that athletes who are engaged in endurance events for life have a high probability of myocardial fibrosis, especially the hardening of heart cells.

This sclerosis will lead to cardiac arrest, leading to arrhythmia. Runners who run more than 25 miles (about 40 kilometers) a week have the same risk of death as those who don't exercise.

Second, musculoskeletal changes.

During exercise, muscles and bones will inevitably be damaged, and it takes 24-48 hours of rest to fully recover. If the muscle fatigue exceeds 48 hours, it means that the physiological function of the exerciser has been excessively challenged, and it also means that his muscle and energy storage have not been effectively restored.

Researchers at Johns Hopkins University School of Medicine believe that chronic fatigue after exercise indicates that athletes overtraining.

Third, changes in the immune system.

Excessive exercise impairs the function of the immune system, because the body needs to fight fatigue and insufficient muscle recovery. Research shows that high-intensity endurance exercise for more than 90 minutes makes athletes prone to get sick within 72 hours after exercise, because strenuous exercise temporarily reduces the function of immune system.

Fourth, hormonal changes.

Overtraining will affect the secretion function of hormones. Athletes will experience an increase in the secretion of cortisol and adrenaline (also known as stress hormones), which will increase blood pressure and cholesterol levels, thus inhibiting the function of the immune system.

Overtraining can also suppress appetite by increasing the secretion of two hormones-adrenaline and norepinephrine. Insufficient calorie intake will slow down the recovery speed and make the discomfort of overtraining more serious.

Verb (abbreviation for verb) sleep change

Excessive exercise brings stress to the body, leading to an increase in cortisol content. The increase of hormones such as cortisol will affect sleep habits. The role of cortisol determines the sleep mode, so if the cortisol content rises excessively before going to bed, it will hinder the quality of sleep.

People's Daily Online-There are five forms of physical injury caused by excessive exercise.