健康生活:你的運動超量了嗎大綱

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Over the last few months, during the endurance-athletics offseason, something extraordinary happened: The line began to blur between the health effects of running marathons and eating cheeseburgers.

過去幾個月耐力賽事的淡季中，發生了一件很不尋常的事情：跑馬拉松和吃芝士漢堡，這兩件事對人體健康的影響的區別開始變得模糊起來。

'I'm not worried, ' says veteran running coach Mark Sullivan, who has run more than 150 marathons, joking that 'there are guys who live to be 100 smoking cigarettes and eating cheeseburgers.'

參加過150餘場馬拉松賽的資深跑步教練馬克??蘇利凡(Mark Sullivan)說：“我一點兒也不擔心。”他還開玩笑稱：“有人又抽菸又吃芝士漢堡還能活到100歲呢。”

Endurance athletes have long enjoyed a made-of-iron image. But amid mounting evidence that extraordinary doses of exercise may diminish the benefits of modest amounts, that image is being smudged. That extra six years of longevity running has been shown to confer? That benefit may disappear beyond 30 miles of running a week, suggests recent research.

長期以來，耐力運動員在世人心目中都是鐵人的形象。但隨着越來越多的證據表明，運動量過大的話，可能會減少適量運動所帶來的益處。這給運動員的鐵人形象蒙上了陰影。不是說跑步能讓人多活六年嗎？新近的研究表明，一週跑步超過30英里（約合48公里），這一好處可能就會消失殆盡。

The improved blood pressure, cholesterol levels and robust cardiac health that exercise has been proven to bestow? Among extreme exercisers, those blessings may be offset partially by an increased vulnerability to atrial fibrillation and coronary-artery plaque, suggests other recent studies.

如果上述說法成立，那跑馬拉松能改善人的血壓、膽固醇水平，並讓心臟變得更爲強健，這些已被證實的事又該作何解釋？近來另一些研究表明，對於過度鍛鍊者而言，由於他們更易患上心房顫動和冠狀動脈斑塊的病症，所以跑馬拉松帶來的一部分好處可能會被抵消掉。

In the face of this research, long-standing skepticism about the possibility of 'exercise overdose' is softening among many sports physicians. 'The lesson I've learned from 40 years of cardiology is that when there's this much smoke, there's often some fire, ' said Paul Thompson, a sports-medicine specialist and veteran marathoner who is chief of cardiology at Hartford Hospital in Connecticut.

許多體育運動醫學家一直都對存在“運動過量”這種可能性的說法表示質疑，但面對上述研究，他們中的很多人態度都在軟化。康涅狄格州哈特福德醫院(Hartford Hospital)心臟病學負責人、運動醫學專家及馬拉松老將保羅??湯普森(Paul Thompson)說：“四十年的心臟病學職業生涯教給我一點：無中不能生有，事出總是有因。”

Anecdotal concerns about endurance athletics have been building for years. Cardiac conditions that required surgery have forced into retirement two winners of the Ironman Triathlon World Championship. In 2011, Ironman winner Normann Stadler underwent emergency surgery to repair an enormous aortic aneurysm, a condition not caused but very possibly aggravated by endurance athletics. Research shows an association between endurance athletics and enlarged aortic roots.

坊間關於耐力運動的擔憂由來已久。鐵人三項世界錦標賽(Ironman Triathlon World Championship)的兩位冠軍得主就因爲心臟病需要動手術而被迫退役。2011年，該賽事冠軍得主諾曼??施泰德(Normann Stadler)就接受了一場治療主動脈巨瘤的急診手術。這種病雖然不是由耐力運動造成的，但後者很可能會加劇病情。研究表明，耐力運動和主動脈根部擴張二者之間存在着某種關聯。

Other recent studies suggest the significant mortality benefits of running may diminish or disappear at mileage exceeding 30 miles a week and other, very small studies have shown elevated levels of coronary plaque in serial marathoners─a problem that rigorous exercise theoretically could cause.

近來另一些研究指出，雖然跑步顯著地降低了死亡率，但如果一週跑步的總里程超過了30英里（約合48公里），這項運動帶來的益處可能就會減少或消失。而其他一些小規模的研究已表明，長期跑馬拉松的人其冠狀動脈斑塊含量升高──這一問題理論上說是有可能由於嚴格的訓練造成的。

'Heart disease comes from inflammation and if you're constantly, chronically inflaming yourself, never letting your body heal, why wouldn't there be a relationship between over exercise and heart disease?' said John Mandrola, a cardiac electrophysiologist and columnist for .

心臟電生理學家、的專欄作者約翰??曼德羅拉(John Mandrola)說：“心臟病源自炎症，如果你長期受慢性炎症困擾，從不讓自己的身體痊癒，那麼，過度鍛鍊和心臟病之間怎麼可能會沒有關係呢？”

Yet sports-medicine specialists are sharply divided over whether any warning is warranted. For every American who exercises to extremes, after all, there are thousands who don't exercise at all─and who might embrace any exercise-related warnings as cause for staying sedentary. Moreover, the evidence for extreme-exercise hazards is far from conclusive─and is contradicted by other studies suggesting the health benefits of exercise may accrue to infinity.

然而，在是否有必要就此發出警告的問題上，運動醫學專家們的分歧很大。畢竟，按美國的人口比例來算，與每一名運動強度直逼極限的人相對應的是成千上萬名根本不運動的人──任何與運動相關的警告都有可能成爲他們繼續坐着不動的理由。此外，“過度鍛鍊是危險的”這一說法還缺少證據，遠未形成定論──而且與其他的研究結果也相矛盾，後者認爲無止境的鍛鍊會有益於身體健康。

'It's true that the majority of cardiovascular protection comes from exercise at more moderate levels, but there is compelling evidence that there's no upper limit, ' said Benjamin Levine, director of the Institute for Exercise and Environmental Medicine in Dallas and professor of medicine at the University of Texas Southwestern Medical Center.

達拉斯運動和環境醫學研究所(Institute for Exercise and Environmental Medicine)負責人、得克薩斯大學西南醫學中心(University of Texas Southwestern Medical Center)醫學教授本傑明??萊文(Benjamin Levine)說：“有一點是確鑿可信的，那就是大多對心血管的保護源自更適度的鍛鍊。但也有令人信服的證據表明，鍛鍊並沒有上限。”

'I don't want anyone to read that exercise can be bad for you. added Mandrola, a passionate cyclist. 'Some folks do tons of exercise and are protected. Some folks probably have some individual susceptibility to it. I'm a big believer in short intervals of high intensity.'

愛好自行車運動的曼德羅拉補充說：“我不希望任何人將其解讀爲鍛鍊可能對人有害。有些人運動量巨大卻仍受其裨益，有些人易感不適可能是由於個人原因所致。我本人就堅信，應該進行短時間隔休息的高強度鍛鍊。”

Sports medicine has a history of ignoring warning signs. Long after evidence emerged that over-hydrating could prove fatal to marathoners, experts continued encouraging runners to drink as much as possible─leading to utterly preventable tragedies such as the death of a 43-year-old mother of three in the 1998 Chicago Marathon. 'Why did it take 20 years before the original evidence was accepted?' asked a 2006 article in the British Journal of Sports Medicine.

運動醫學界有着對警告信號熟視無睹的歷史。有證據表明，補水過度可能會對馬拉松選手造成致命傷害。這一發現提出很久以後，專家們還是繼續鼓勵跑步者儘可能多地喝水──這就導致了一些原本完全可以避免的悲劇的上演，比如1998年在芝加哥馬拉松賽(Chicago Marathon)中喪生的那位選手，她當時43歲，是三個孩子的母親。2006年，《英國運動醫學雜誌》(British Journal of Sports Medicine)發表的一篇文章提出了這樣一個問題：“爲什麼這個原始證據在二十年之後才被人接受？”

Following the recent emergence of studies finding high levels of coronary plaque in marathon runners, sports medicine is debunking the myth that distance running confers near-absolute protection against heart disease. 'The thinking used to be, if you're a marathoner, you're protected, ' said Thompson. While taking seriously the growing evidence for potential risks of endurance exercise, Thompson said he isn't advising his patients against it. 'As a former marathoner, I have a sympathetic bent toward large amounts of exercise.'

新近諸多研究發現馬拉松選手的冠狀動脈斑塊水平偏高後，運動醫學界正在打破這樣一種誤解：長跑會對心臟病起到一種近乎絕對的防護作用。湯普森說：“過去有這樣一種看法：如果你是一名馬拉松運動員，你就得到了保護。”然而，越來越多的證據表明耐力運動存在潛在風險。儘管很看重這些證據，但湯普森說他並不建議自己的患者放棄耐力運動，“作爲一名曾經的馬拉松選手，我也偏愛大量的鍛鍊”。

Publicizing the potential dangers of endurance exercise could give recreational athletes an argument for resisting pressure to go longer and harder. Within the running and triathlon communities, glory is often reserved for those who go extreme distances. 'The longer you go, the more attention people pay to you, ' said Aaron Baggish, a triathlete, marathoner and Massachusetts General Hospital cardiologist.

向公衆宣傳耐力運動的潛在危險可能會給業餘運動員一個淺嘗輒止的理由，在面臨需要他們跑得更遠、付出更多努力的壓力時會產生抗拒。在跑步和鐵人三項的圈子裏，榮譽總是留給那些願意挑戰里程極限的人。波士頓麻省總醫院(Massachusetts General Hospital)心臟病專家、鐵人三項和馬拉松選手亞倫??巴吉胥(Aaron Baggish)說：“你跑得的路越長，得到的關注也就越多。”

The loudest voice warning about the dangers of endurance exercise may be that of James O'Keefe, a sports cardiologist and former elite triathlete. In his late forties, O'Keefe started experiencing heart palpitations following heavy workouts. He now believes the culprit was unrelenting exercise. An article he co-wrote last year in the Mayo Clinic Proceedings said: 'Long-term excessive endurance exercise may induce pathological structural remodeling of the heart and large arteries.'

在關於耐力運動有危險的警告聲中，最響亮的聲音可能來自詹姆斯??歐基夫(James O'Keefe)。身爲運動心臟病專家的歐基夫曾是一名鐵人三項精英賽選手，但臨近50歲時，歐基夫在進行高強度鍛鍊後開始出現心悸。他現在認爲無休止的運動是這一切的罪魁禍首。去年，《梅奧診所學報》(Mayo Clinic Proceedings)發表了歐基夫與他人合着的一篇文章，其中寫道：“長期過度的耐力運動可能會誘發心臟和大動脈產生病理結構性重建。”

As director of a decades-long project called the National Runners' Health Study, Paul Williams has published dozens of scientific articles showing that running─the more the better─confers a variety of robust health benefits. But along with Hartford's Thompson, Williams just completed a study of 2, 377 runners and walkers who had survived heart attacks. Over 10.4 years, 526 of them died, 71.5% of them from cardiovascular disease. What Williams found is that the more they ran or walked after a heart attack, the less likely they were to die of heart disease─until they exceeded 7.1 kilometers of running or 10.7 kilometers of walking daily.

全美跑步者健康研究(National Runners' Health Study)是一個持續了數十年的項目，該項目負責人保羅??威廉姆斯(Paul Williams)已發表了幾十篇科學論文，文章均表明跑步──越多越好──給人的健康帶來了種種好處。但威廉姆斯也與哈特福德醫院的湯普森一起完成了針對2,377名在心臟病後存活了下來的跑步者和步行者的一項研究。在10.4年的時間裏，共有526名參與者去世，其中71.5%的人死於心血管疾病。威廉姆斯發現，他們在心臟病發後跑得越多或走得越多，其死於心臟病的風險就越小，前提是他們的運動里程不能超過臨界點──一天跑步超過7.1公里或走路超過10.7公里。