運動後的肌肉痠痛和被冤枉的乳酸
After rigorous exercise, muscle pain is more acute a day or two later rather than immediately. Why?
劇烈運動之後的第二天或第三天，肌肉會比運動剛結束時更加痠痛。爲什麼會出現這種情況呢？
Welcome to the equivocal effects of delayed onset muscle soreness, the scientific term for aches that accumulate and intensify a day or two after a strenuous workout. Usually, D.O.M.S. involves not just pain but also “loss of strength and range of motion in the affected area,” said Scott Sailor, a professor of kinesiology at Fresno State University in Fresno, Calif., and the president of the National Athletic Trainers’ Association.
其背後原因是讓人感覺莫名其妙的延時發作肌肉痠痛（delayed onset muscle soreness，簡稱DOMS），這一科學用語用來定義高強度鍛鍊結束一兩天後積累和加劇的肌肉痠痛。通常，DOMS不僅僅是痛，“受到影響的身體部位還會感到無力和活動困難，”位於加州弗雷斯諾市的加州州立大學弗雷斯諾分校的運動機能學教授、美國運動傷害防護協會(National Athletic Trainers’ Association)主席斯科特·賽勒(Scott Sailor)說。
D.O.M.S. commonly occurs after exercise that involves lengthening muscles while they contract, Dr. Sailor said, such as running downhill. But it can develop after any exertion that is more intense or prolonged than is normal for you.
賽勒博士表示，在肌肉處於收縮狀態時進行拉伸，比如下坡奔跑，通常會引起DOMS。但是，任何強度或時長超過自身正常接受範圍的運動，都有可能導致DOMS。
Such strenuous workouts can cause multiple slight tears to the muscle tissue, after which a variety of cells and substances migrate to these muscles to help them start healing.
劇烈運動會導致肌肉組織出現很多輕微撕裂，之後各種細胞和物質會移動到這些肌肉組織中，幫助它們開始癒合。
Interestingly, these substances are not necessarily the same as those that arrive after a more severe muscle injury. Molecules that promote inflammation and swelling, for instance, tend to predominate in tissues affected by a serious injury, but can be absent in tissue affected by D.O.M.S., recent studies show.
有趣的是，這些物質與經過更嚴重的肌肉拉傷後出現的物質不一定相同。比如，最近的一些研究顯示，會促發炎症和腫脹的分子，比較多出現在嚴重拉傷後的肌肉組織中，而在有DOMS症狀的輕微受損組織中卻不存在。
Similarly, “there was a time when we attributed the muscle soreness to lactic acid,” Dr. Sailor said. “We have now learned that lactic acid leaves the muscle so quickly” that it cannot be involved in causing D.O.M.S.
同樣有意思的是，“我們一度把肌肉痠痛歸因於乳酸的存在，”賽勒博士說。“現在我們知道，乳酸很快會從肌肉中消失”，所以它不會引起DOMS。
In essence, researchers remain puzzled about what cellular reactions cause D.O.M.S. There is also controversy about how to treat it.
實際上，研究人員還沒弄清楚，到底是什麼細胞反應引起了DOMS。對於如何治療它，也存在爭議。
“Various treatments have been attempted over the years,” said Dr. Sailor, including massage, icing and anti-inflammatory painkillers. “At best, they have decreased the perception of pain,” he said, but only temporarily.
“過去多年，我們嘗試過各種治療方法，”賽勒博士說，包括按摩、冰敷和服用消炎止痛藥物。“這些辦法至多能減輕一些疼痛感，”他說，而且其作用也是暫時的。
So if you do develop D.O.M.S., accept that, for the next five to seven days, you are going to be sore. Refrain from strenuous exercise during this time, Dr. Sailor said, although gentle walking is fine. And, if it is any consolation, your muscles should be stronger after they recover.
所以如果你出現了DOMS症狀，只能忍着，接下來的五到七天裏，它會一直都會疼下去。賽勒博士表示，這段時間裏，不宜進行劇烈運動，可以徐緩地散散步。要說有什麼能讓你感到安慰，那就是在恢復之後你的肌肉應該會變得更強壯。
In your future workouts, Dr. Sailor said, increasing the duration or intensity gradually should increase strength and fitness to limit the potential of experiencing the effects of D.O.M.S.
賽勒博士表示，在以後的運動中，逐步增加運動時長和強度，應該可以增強肌肉力量和適應性，進而減少出現DOMS的情況。
