0 1 Long-term aerobic exercise will reduce body fat and consume excess muscle, so long-distance runners are very thin. At the same time, endurance exercise pays more attention to the efficiency of respiratory system and blood oxygen intake, and excessive muscle will lead to increased oxygen consumption. Therefore, when choosing a long-distance runner, in addition to choosing a good endurance, you must choose a slim figure.

There are few fat athletes in track events, because running is aerobic exercise, so it needs a lot of energy. The preferred consumer goods for human body are protein sugar, followed by fat. After professional training, muscle endurance and liver metabolism have reached a high level. Running for a long time often consumes a lot of protein in the body, and the most important substance for synthesizing muscle fiber is protein. When the intake of protein can't meet the needs, it will consume muscle tissue and make people thin.

Horizontal muscles of the same size contain more protein, higher muscle density, stronger flexibility and denser blood vessels. The liver transports energy faster and the body is more durable. Generally speaking, muscle refinement is a good natural law. You will find that the thighs and legs of long-distance running are well developed, and the muscle lines of the legs are actually not small.

Long-distance running will not increase muscle mass, but will increase muscle toughness. And a strong runner will be better than losing weight. Therefore, when choosing athletes at the beginning, we will not choose those big, long-distance runners.