概述：

缺鐵分為三個(gè)階段：第一也即最常見(jiàn)的階段，是鐵質(zhì)儲(chǔ)量不足。。。

Hints:

無(wú)

PS:1秒左右有連字符，45秒左右有破折號(hào)

Athletes in high-impact sports such as running may also lose iron through a phenomenon where small blood vessels in the feet leak blood. There are three stages of iron deficiency. The first and most common is having low iron reserves, a condition that typically has no symptoms. Fatigue and poor performance may begin to appear in the second stage of deficiency, when not enough iron is present to form the molecules of blood protein that transport oxygen to the working muscles. In the third and final stage, people often feel weak, tired, and out of breath - and exercise performance is severely compromised.
運(yùn)動(dòng)員從事跑步之類(lèi)高強(qiáng)度劇烈運(yùn)動(dòng)，也可能會(huì)因?yàn)樽悴垦苁а默F(xiàn)象而使鐵質(zhì)流失。 缺鐵分為三個(gè)階段：第一也即最常見(jiàn)的階段，是鐵質(zhì)儲(chǔ)量不足。這一階段一般沒(méi)有癥狀。到了缺鐵的第二階段，就會(huì)出現(xiàn)疲倦和力不從心，此時(shí)體內(nèi)已沒(méi)有足夠的鐵來(lái)形成血蛋白分子，將氧輸至運(yùn)動(dòng)肌肉。在第三即最后階段，人常常感到虛弱、疲乏無(wú)力、喘不過(guò)氣，運(yùn)動(dòng)成績(jī)大打折扣。