One of the signs of bodybuilding is the degree of muscle development. There are four keys for muscle to become strong and stout: first, strong contraction makes muscle fibers thicker and bigger; Second, the connective tissue that supports and transmits strength is strengthened and thickened; Third, after receiving high-intensity stimulation, muscles will be over-supplemented, which will increase the total protein of muscles; Fourthly, increase the capillary openings for supplying oxygen and nutrients through exercise.

Smoking will have adverse effects on the above four aspects, especially on capillaries. At ordinary times, only 30-270 capillaries are opened per square millimeter of muscle cross-section, and as many as 2,000-3,000 capillaries can be opened during body-building exercise. People who exercise regularly will greatly increase the capillary opening 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 consume the reserves of vitamin C in the human body and completely destroy human health. "Absolutely quit smoking" is the knowledge of all bodybuilding coaches.