First, when exercising, the skin pores become larger. When you blow the air conditioner, the pores are closed and you can't sweat.
The second exercise makes the muscle bigger, the muscle capillary fiber breaks and the blood flows in, which will make people excited and improve the exercise effect. Muscle cooling, people are not in a state of exercise,
Third, joints are not easily injured only at high temperatures. If the air conditioner is blown, the joint tendons will tighten, which will easily increase the chance of injury. Look at all the athletes. They all packed up before going out ... it's the same thing to wear a hooded cloak and a weight-lifting leather blanket in boxing!