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.

    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.

    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 U.S. 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.

    來自健康學家的新提醒：久坐致命。

    科學家開始越來越多地提醒久坐的人們--就算經常運動--久坐也對身體健康不利。不管坐在什么地方--辦公室也好，學校也好，車上或是電腦電視前--總而言之，只要久坐，都對身體健康不利。

    雖然這只是個初步的研究，但是多份報告表明大部分時間都坐著的人更可能肥胖，患心臟病甚至死亡。

    本周英國體育醫學雜志的一篇社論中，瑞典體育學院的 Elin Ekblom-Bak 建議專家們重新定義體育運動的含義以強調坐著的危害性。

    然而衛生部的官員卻提出了最小體育運動量一說，他們不贊同一個坐姿需要限制在多長時間內的說法。

    即使是常運動的人，在桌前久坐不動也對健康有害。Tim Armstrong,世界衛生組織的一位體育運動專家說，每天運動即使久坐，如果以運動貫穿全天，而不只是一時興起才運動一下的人，可能可以從中獲利。

    這對于現年31歲，在倫敦金融公司工作的Aytekin Can來說可不是個愉快的消息，要知道他的大部分時間都得坐在電腦前。一個星期里有好幾個晚上，Can還要教授柔術，一種融合了摔跤的日本武術，同時他還練習泰拳。

    而研究人員對17,000多名加拿大人進行了長達10多年的跟蹤調查，并于去年公布了研究報告，結果表明久坐的人死亡率更高，這與他們是否鍛練無關。

    一份來自美國2003年到2004年間的調查數據顯示，美國人從坐在桌前辦公到坐在車里，多半時間都是坐著的。

    另有專家指出這需要更多的調查才能知道坐多久才是造成危害的量，還有就是如何才能消除久坐的危害。