Muscles will gradually become familiar with external stimuli. For example, an otaku is suddenly called to run for 5,000 yuan, and his body must be overwhelmed. If he starts to practice slowly from 1000 yuan, he won't feel tired after getting used to it. Your strength is not enough now, so your muscle reaction is not very great. With a good rest and adequate nutrition, he naturally won't feel too tired. It is suggested to gradually increase the quantity and time on the original basis.