Mark Ramirez, a senior executive at AOL, could work in the cushiest leather chair, if he wanted. No, thanks. He prefers to stand most of the day at a desk raised above stomach level。

　　"I've got my knees bent, I feel totally alive," he said. "It feels more natural to stand."

　　In the past few years, standing has become the new sitting for 10 percent of AOL employees at the firm's Virginia campus, part of a standing ovation among accountants, programmers, telemarketers and other office workers across the nation。

　　GeekDesk, a California firm that sells $800 desks raised by electric motors, says sales will triple this year。

　　Standers give various reasons for taking to their feet: It makes them feel more focused, prevents drowsiness, makes them feel like a general even if they just push paper. (Former defense secretary Donald Rumsfeld works standing up. So does novelist Philip Roth。)

　　But unknown to them, a debate is percolating among ergonomics experts and public-health researchers about whether all office workers should be encouraged to stand — to save lives。

　　Doctors point to surprising new research showing higher rates of diabetes, obesity, heart disease and even mortality among people who sit for long stretches. A study earlier this year in the American Journal of Epidemiology showed that among 123,000 adults followed over 14 years, those who sat more than six hours a day were at least 18 percent more likely to die during the time period studied than those who sat less than three hours a day。

　　"Every rock we turn over when it comes to sitting is stunning," said Marc Hamilton, a leading researcher on inactivity physiology at the Pennington Biomedical Research Center in Louisiana. "Sitting is hazardous. It's dangerous. We are on the cusp of a major revolution." He calls sitting "the new smoking."

　　Not so fast, other experts say. Standing too much at work will cause more long-term back injuries. Incidences of varicose veins among women will increase. The heart will have to pump more。

　　Hedge, the Cornell professor, isn't a fan of all this standing. "Making people stand all day is dumb," he said。

　　The sensible and most cost-effective strategy, he said, is to sit in a neutral posture, slightly reclined, with the keyboard on a tray above the lap. This position promotes positive blood flow. Workers should occasionally walk around, stretch and avoid prolonged periods at the desk. The key, he said, is movement, not standing。

　　美国在线公司的高级主管马克•拉米瑞茨完全可以坐在最舒适的皮椅上工作——如果他愿意的话。但是，谢谢了。大部分时间他更喜欢站在一张桌面高于他的腹部的桌子前办公。

　　他说：“我的膝盖可以弯曲，我觉得自己充满活力。站着工作感觉更自然。”

　　过去几年来，在美国在线位于弗吉尼亚州的分公司中，10%的员工都采取站立这一新“坐姿”，除了他们以外，全国有许多会计人员、编程人员、电话营销人员和其它办公室职员都开始流行站着工作。

　　总部位于加州的GeekDesk公司出售电动办公桌，价格可达800美元。该公司称今年的销售额预计将增长两倍。

　　站着工作的人给出了选择站立的各种理由：站立可以使他们注意力更集中，驱散睡意，而且就算他们只是在做琐碎的工作，也会感觉自己像个将军。(美国前国防部长唐纳德•拉姆斯菲尔德也是站着工作的。小说家菲利普•罗斯也是如此。)

　　但他们并不知道，围绕着是否应该鼓励所有办公室职员都站着工作这一话题，在人类工程学专家和公共健康研究员当中展开了一场以拯救生命为目的的辩论。

　　医生们指出，新研究惊人的结果显示，长时间坐着工作的人患糖尿病、肥胖症、心脏病甚至是死亡的几率都比站立工作者要高。《美国流行病学杂志》在今年早些时候发表的一项研究表明，在研究进行期间，那些一天静坐超过6个小时的人的死亡率，比那些静坐时间少于3小时的人，高出至少18%。该研究在14年的时间内对12.3万名成人进行了跟踪调查。

　　马克•汉密尔顿是美国路易斯安那州彭宁顿生物医学研究中心的权威研究人员，他的研究方向是缺乏运动状态下的生理学。他说：“我们有关久坐的每项研究结果都令人震惊。久坐是有害的，是危险的。我们正处于一场重大变革的风口浪尖。”他将久坐称为“一个像吸烟一样有害的新杀手”。

　　但是，其他专家认为，还不应该过早下结论。工作中站立过久会导致更多的慢性背部损伤。而且女性静脉曲张发病率会增加。心脏负荷也会加大。

　　康奈尔大学的海奇教授也不提倡站着工作。他说：“让人们整天站着工作是愚蠢的主张。”

　　他认为，一个合理且经济的方法就是，坐姿要适中，微微靠向椅背，将键盘放在高于膝盖的托盘上。这个姿势可以促进血液循环。员工应该不时地四处走动，舒展一下身体，避免长时间坐在办公桌前。他说，关键在于运动，而非站立。