Because swimming is a whole-body physical exercise, not an aerobic exercise. When doing aerobic exercise, the whole body will be tired. Only in this way can we achieve the effect of fitness. As long as you persist, you won't be tired in the future, and exercising physical endurance is also a good fitness exercise.

People who have just learned to swim and haven't swam for a long time haven't adapted their muscles to heavy exercise. Coupled with hypoxia, suffocation, water pressure, dehydration and other factors, swimmers will feel particularly tired and feel very tired. However, athletes who often swim get into the water and become energetic. They will feel tired when swimming, but they won't feel very tired.

Extended data

Matters needing attention

1. You must swim under the guidance of your parents (guardians). Swimming alone is the most prone to problems. If your companion is not a parent (adult), it is difficult to guarantee that you can get proper help when you are in danger. (taboo for children)

People who are sick should not go swimming. Patients with chronic diseases such as otitis media, heart disease, dermatosis, liver and kidney diseases, hypertension, epilepsy and pinkeye, as well as those with colds, fever, mental fatigue and physical weakness, should not go swimming, because these patients are not only prone to aggravate their illness, but also prone to cramps, accidental coma and life-threatening.

3. After taking part in strong physical labor or strenuous exercise, you can't jump into the water to swim immediately, especially when you are sweating or fever. Otherwise, it is easy to cause cramps and colds.