Colds are mainly caused by the upper respiratory tract being susceptible to viral invasion and infection when the body’s immunity drops due to cold. As the cold just when the body’s immunity may not have been fully restored, and fitness needs to consume a lot of energy, resulting in the body in a more exhausted state, and the immune system recovery also needs energy. Therefore, working out after catching a cold may affect the recovery of immune function, and may even lead to low immunity, which may lead to diseases caused by bacteria or viruses again. It is usually recommended that people who have just caught a cold should rest for 3-5 days until their immune system has fully recovered before working out. During this period, people should pay more attention to keep warm, drink more hot water and rest more.