Normally, you don't. Pay attention to swimming at least one hour after practicing the equipment, so that your body can fully recover and avoid swimming danger. Precautions for swimming: 1. Don't go swimming alone, especially children can only go into the water under the supervision of adults. 2, swimming before meals, you will feel physically exhausted, easy to collapse. Swimming with a full stomach after a meal is easy to cause vomiting. Anyway, swimming before and after meals will cause physical discomfort, so it is best to go swimming 2 hours after meals. 3. For friends who are not good at swimming in deep water, please remember to bring swimming ring AIDS. 4, swimming time should not be too long, I don't know if you have such an experience, that is, soaking in the water for too long, I feel very uncomfortable, and I have had it. So the swimming time should not be too long, preferably within 2 hours. 5, do not swim during menstruation, for women, menstrual body resistance is poor, swimming, will make bacteria enter the body, causing infection. Therefore, female friends should not swim during menstruation. 6. Don't swim in unfamiliar waters, such as wild reservoirs, lakes and unfamiliar rivers. In unfamiliar waters, you don't know the depth of water, the distribution of underwater stones, weeds and so on. Inadvertently entering the water will increase the probability of drowning accidents. 7. Pay attention to water hygiene when swimming, and don't swim in unclean rivers, lakes and swimming pools to reduce the possibility of infectious diseases and various diseases.