The first type: the body does not adapt to the performance of fitness training. Because you seldom exercise, or have never trained with such intensity, it is definitely unacceptable for your body to suddenly give such high-intensity training. This kind of training will destroy the internal environment of the body, increase some acidic substances in the body and reduce the exercise ability of the body. After training, the body needs to restore the internal environment to stability, and it will show various maladjustments in the process of recovery. The essence of fitness is to constantly give the body new excitement, so that the body can never adapt to its own fitness rhythm, and the physical quality can become stronger. Muscle pain after fitness, is this normal?

The second one: during fitness training, some muscle fibers, tendons and ligaments were damaged, torn and convulsed. In resistance training, especially in training with relatively large range of activities and heavy weight, muscles are fully contracted and fully stretched, which will cause damage to muscles. When exercising, the muscles will press the nerves, and the nerves will go into a state of numbness. When you rest the next day, it will return to normal, and when your muscles are damaged, it will turn into pain. So this kind of pain is a good sign that your fitness training is effective.