健康專家：久坐可致命大綱

Here's a new warning from health experts: Sitting is deadly. Scientists are increasingly warning that sitting for prolonged periods — even if you also exercise regularly — could be bad for your health. And it doesn't matter where the sitting takes place — at the office, at school, in the car or before a computer or TV — just the overall number of hours it occurs.

Research is preliminary, but several studies suggest people who spend most of their days sitting are more likely to be fat, have a heart attack or even die.

In an editorial published this week in the British Journal of Sports Medicine, Elin Ekblom-Bak of the Swedish School of Sport and Health Sciences suggested that authorities rethink how they define physical activity to highlight the dangers of sitting.

While health officials have issued guidelines recommending minimum amounts of physical activity, they haven't suggested people try to limit how much time they spend in a seated position.

"After four hours of sitting, the body starts to send harmful signals," Ekblom-Bak said. She explained that genes regulating the amount of glucose and fat in the body start to shut down.

Even for people who exercise, spending long stretches of time sitting at a desk is still harmful. Tim Armstrong, a physical activity expert at the World Health Organization, said people who exercise every day — but still spend a lot of time sitting — might get more benefit if that exercise were spread across the day, rather than in a single bout.

That wasn't welcome news for Aytekin Can, 31, who works at a London financial company, and spends most of his days sitting in front of a computer. Several evenings a week, Can also teaches jiu jitsu, a Japanese martial art involving wrestling, and also does Thai boxing.

"I'm sure there are some detrimental effects of staying still for too long, but I hope that being active when I can helps," he said. "I wouldn't want to think the sitting could be that dangerous."

Still, in a study published last year that tracked more than 17,000 Canadians for about a dozen years, researchers found people who sat more had a higher death risk, independently of whether or not they exercised.

Figures from a US survey in 2003-2004 found Americans spend more than half their time sitting, from working at their desks to sitting in cars.

Experts said more research is needed to figure out just how much sitting is dangerous, and what might be possible to offset those effects.

"People should keep exercising because that has a lot of benefits," Ekblom-Bak said. "But when they're in the office, they should try to interrupt sitting as often as possible," she said. "Don't just send your colleague an e-mail. Walk over and talk to him. Standing up."
健康專家日前發出最新警告：久坐會致命。越來越多的科學家提醒，即使經常鍛鍊身體，長時間坐着也會對健康產生有害影響。而且不管你坐在哪裏——辦公室、學校、車上或是電腦、電視前——重要的是你坐着的時間。

目前該研究尚處於初步階段，但已有幾項研究顯示，每天大部分時間都處於靜坐狀態的人更容易發胖、患心臟病甚至死亡。

瑞典體育及健康科學學院的艾琳•艾克布洛姆-巴克上週在英國《運動醫學》雜誌上發表的一篇評論文章中建議，相關機構應重新考慮如何界定身體鍛鍊，以強調久坐的危害。

儘管衛生官員已發佈指南建議人們的最低身體活動量，但在一天最多坐幾個小時的問題上還是個空白。

艾克布洛姆-巴克說：“在坐了四個小時後，身體會開始發出有害信號。”她解釋說，此時調節體內葡萄糖和脂肪量的基因會開始罷工。

即使對那些經常鍛鍊的人來說，長時間坐着也有害。世界衛生組織的身體鍛鍊專家蒂姆•阿姆斯特朗說，對於那些每天鍛鍊但依然有很多時間是處於靜坐狀態的人來說，如果每天的鍛鍊可分散進行而不是一次集中完成，效果會更好。

這對於在倫敦一家金融公司工作的31歲的艾特金•肯來說不是什麼好消息。肯每天大部分時間都坐在電腦前。不過他每週有幾個晚上教授柔術（日本的一種摔跤武術），此外還練泰國拳擊。

他說：“我知道長時間坐着不動肯定有害，但我希望我做的這些運動能起到作用。我不願相信坐着會產生這麼危險的後果。”

去年公佈的一項研究發現，長時間坐着的人死亡率更高，無論他們是否從事身體鍛鍊。這項研究在12年內共對超過1.7萬名加拿大人進行了跟蹤調查。

美國2003年至2004年的一項調查數據顯示，美國人每天有一半以上的時間處於靜坐狀態，無論是坐在辦公桌前還是坐在車內。

專家稱，還需要開展更多研究以測算每天坐多久會對健康產生威脅，以及怎樣來消除這些有害影響。

艾克布洛姆-巴克說：“人們應該堅持鍛鍊，因爲鍛鍊身體益處多多。但當他們在辦公室時，應該儘可能多地起來活動活動。不要總是通過發電郵來與同事交流。可以走過去與他面談。站着談。”

Vocabulary:

glucose: a type of sugar that is found in fruit and is easily changed into energy by the human body 葡萄糖

bout: a short period of great activity 一次

jiu jitsu: a method of self-defense without weapons that was developed in China and Japan; holds and blows are supplemented by clever use of the attacker's own weight and strength 柔術