At ordinary times, only 30~270 capillaries are opened per square millimeter of muscle cross section of human body, and as many as 2,000-3,000 capillaries can be opened during fitness exercise, and the amount of capillaries opened by people who exercise regularly will be greatly increased even at ordinary times. Nicotine in tobacco can promote capillary contraction and hardening, which greatly reduces the exercise effect. At the same time, it will also consume the reserves of vitamin C in the human body. "Absolutely quit smoking" is the knowledge of all bodybuilding coaches.