1, the principle of gradual progress. At the beginning of exercise, there is a certain limit to the intensity of exercise that the human body can bear. It takes time for the body to get used to it and then gradually increase its strength. Sudden overload, which exceeds the adaptability of human body, will cause excessive fatigue and even sports injury.

2. The principle varies from person to person. Everyone's physical condition is different, and the sports and intensity are also different. According to the actual situation, we should choose the most suitable training scheme to achieve the best training effect.

3. The principle of perseverance. Fitness is not achieved overnight, and it needs a lot of repeated exercise for a long time. Once you give up halfway, the fitness effect will gradually disappear and fall short. It is necessary to strengthen the awareness of fitness, take fitness as the content of daily life, and gradually form a habit to stick to it.