Promote the development of cardiopulmonary function: 14-year-old boys can exercise in the gym for 20 days, which can increase the cardiac output of teenagers and is very beneficial to prevent adult diseases such as atherosclerosis, hypertension and coronary heart disease.

Promote physical development: Teenagers are in the period of growth. Teenagers who often participate in physical exercise and fitness have obviously enhanced their metabolism, physical consumption and heat production ability.