Generally, tights are worn in long-term endurance sports, the main purpose is to improve sports performance and promote recovery after sports. In addition, it also has the functions of stabilizing muscles, preventing thigh friction, promoting perspiration or heat preservation, sun protection and preventing venous thrombosis of lower limbs during long-term travel.

The pressure generated by the compression of underwear helps to accelerate the blood flow to the heart and reduce the heart rate (some experiments show that it can be reduced by about 0.8bpm, source: landing page), just like a person soaking in a swimming pool, the pressure of water on the body will reduce the heart rate. Therefore, everything related to accelerating blood return to the heart has become the advertised benefits of compression clothing, such as improving the oxygen supply rate of blood to muscles, accelerating the decomposition of lactic acid, reducing swelling, accelerating recovery and so on.

But the actual effect is not clear, mainly depending on personal subjective feelings. The most obvious thing is that in an endurance race, players with or without clothes have no obvious advantage.