1. It is definitely not possible to wear ordinary underwear, because ordinary underwear is generally pure cotton for comfort and hygiene. And this is just fatal for long-distance running.

2. The pure cotton material will stick to the skin after being soaked by sweat, and the coefficient of friction with the skin will increase. Therefore, it is reasonable to wear underwear to prevent friction when running, and it is a sports bra with excellent performance.

3. Generally speaking, most of sports bra will use polyester fiber, which has good elasticity and is generally tight in cutting. The advantage is that it will be better wrapped.