游泳是夏天最受人喜爱的运动,但是有些人游泳时会发生腿抽筋的现象。如果在江河湖海等天然水域中发生抽筋是很危险的。抽筋,医学上叫作肌肉痉挛,此时肌肉处于强烈的收缩状态,痉挛的部位无法运动,并且伴有剧烈的疼痛。那么为什么会出现肌肉痉挛呢?一般来说原因有两个;第一,下水前没做准备活动,而是突然跳到水里,过冷的刺激使肌肉反射性收缩;第二,在水中运动时间过长,体内代谢产物 Swimming is the summer’s favorite sport, but some people have leg cramps when swimming. It is dangerous to cramp in natural waters such as rivers, lakes and seas. Cramps, medically known as muscle spasms, when the muscles in a strong contraction of the spasm of the site can not exercise, and accompanied by severe pain. Then why there is muscle spasms? Generally speaking, there are two reasons: first, did not prepare before the launch activities, but suddenly jump into the water, cold stimulation of muscle reflex contraction; second, exercise in the water Over time, the body metabolites