According to the research of sports medicine experts, when people exercise, the blood flowing to muscles increases and the heart rate accelerates. When exercise stops, blood flow and heart rate will be relieved, but it will last for a long time. If you take a bath immediately, it will increase the blood flow to your skin and muscles. In this way, the remaining blood is not enough to supply other important organs, such as the heart and brain, which leads to heart disease.
Some people take a hot bath after exercise, and then often feel dizzy and weak, which is the reason mentioned above. Especially the elderly or obese, you can't take a hot bath immediately after exercise.