If you exercise excessively and sweat, it is best to take a bath about 30 minutes after exercise. After strenuous exercise, in order to keep the body temperature constant, blood vessels on the skin surface expand, sweat pores increase and sweat increases, which is beneficial to heat dissipation. At this time, if you take a cold bath, the blood vessels will contract immediately due to sudden stimulation, the blood circulation resistance will increase, the burden on the heart will increase, and the body's resistance will decrease, and people will easily get sick. If you take a hot bath, the blood flow to the skin will continue to increase, and too much blood will flow into the muscles and skin, resulting in insufficient blood supply to the heart and brain, dizziness in the light, collapse and shock in the heavy, and other chronic diseases will be easily induced. So after strenuous exercise, you must rest before taking a bath.