胸围是测量青少年生长发育和青春发育的重要指标之一。胸围表示胸廓的容积及胸部骨骼、肌肉和脂肪层的发育情况,它在一定程度上说明身体的形态及呼吸器官的发育情况,间接地反映肺活量的大小和体育锻炼的效果。儿童时期胸廓狭小,胸廓处于逐年发育扩大阶段,呼吸肌较弱,肺内的容量相对地较小,每次的呼吸量远远低于成人,可是他们代谢却非常旺盛,对氧气的需要 Bust is to measure one of the important indicators of adolescent growth and development. Bust represents the volume of the thorax and the development of the bones, muscles and fat layer of the chest. To a certain extent, it shows the body shape and the development of respiratory organs, and indirectly reflects the size of vital capacity and the effect of physical exercise. Small chest in childhood, the thorax in the growing phase of the development and expansion of each year, the weaker respiratory muscles, lung capacity is relatively small, each breath is much lower than adults, but their metabolism is very strong, the need for oxygen