During and after exercise, the exercise fatigue we feel mainly comes from two aspects: on the one hand, the "fatigue" directly felt by the body, on the other hand, the mental fatigue, and the two are intertwined.
In fact, all kinds of theories about sports fatigue mainly focus on these two aspects. Below, we each choose some representative theories to discuss sports fatigue.
How does physical exercise fatigue come about? "Exhaustion Hypothesis" holds that the main reason of exercise fatigue is that a large amount of energy substances in the human body are consumed during exercise, so it will cause fatigue. This is consistent with the direct physical feeling of the exerciser and is more acceptable. For example, high-intensity exercise in a short period of time will obviously reduce the content of ATP (adenosine triphosphate, the most direct energy source in organisms), and long-term exercise will easily lead to hypoglycemia.
Another "blocking theory" holds that the cause of exercise fatigue is the accumulation of metabolites produced by exercise in muscle tissue, such as lactic acid accumulation. But now some people think that muscle soreness caused by exercise is not necessarily related to lactic acid, but is caused by micro-level "inflammation" caused by exercise.
The more popular theory is the "free radical hypothesis". According to this theory, the increase of oxygen consumption, the increase of energy metabolism and the decrease of antioxidant enzyme activity during exercise will all lead to the increase of free radicals in human body. Free radicals can destroy human cells, and lipid peroxides can spontaneously decompose to form more free radicals, which makes the fatigue situation more serious.
In fact, the free radical hypothesis is not only applicable to "exercise fatigue", but also one of the representative theories about human aging.
How does mental exercise fatigue come about? The representative is the "protection inhibition hypothesis". According to this theory, during long-term and high-intensity exercise, the cerebral cortex will be in a state of continuous high excitement. But this state cannot be maintained forever, and brain cells will reduce work efficiency over time. At the same time, in order to prevent the excessive loss of brain cells under high-intensity work, the excitement of the cerebral cortex will be automatically suppressed, thus playing a protective role.
Sports scientists also found that in strength training, the effective time for the trainer to concentrate is usually about 45 minutes. The training time is too long, and the concentration drops, which affects the training quality and efficiency.
It can be seen that sports fatigue is not only physical fatigue, but also mental fatigue.
How to promote physical recovery after exercise? Athletes can mainly relieve and eliminate sports fatigue through three measures:
(1) Relaxation and finishing activities after exercise can't be omitted. Completing relaxation activities can effectively relieve delayed muscle soreness and promote the subsequent recovery speed of the body.
(2) Pay attention to nutritional supplements. Since exercise consumes a lot of energy substances, it is necessary to supplement various nutrients in time, among which protein, fat and carbohydrate are the most important macro nutrients.
(3) Other recovery methods. Among them, stretching and sleep are more important, and a small amount of aerobic exercise can also quickly relieve muscle soreness.