少坐多运动 一定会更长寿吗

If people need motivation to get up from their office chairs or couches and become less sedentary, two useful new studies could provide the impetus. One found that sitting less can slow the aging process within cells, and the other helpfully underscores that standing up — even if you are standing still — can be good for you as well.
如果人们需要一些动力才愿意从办公椅和沙发上站起来，少坐一会儿，那么两项有用的新研究能提供这种动力。其中一项研究发现，少坐能减缓细胞衰老速度；另一项研究强调站立——哪怕只是静静地站着——也对健康有益。

For most of us nowadays, sitting is our most common waking activity, with many of us sitting for eight hours or more every day. Even people who exercise for an hour or so tend to spend most of the remaining hours of the day in a chair.
静坐是我们大部分人清醒时最常见的状态，很多人每天坐八小时以上。甚至连那些每天锻炼一小时左右的人其他大部分时间也都是坐着。

The health consequences of this sedentariness are well-documented. Past studies have found that the more hours that people spend sitting, the more likely they are to develop diabetes, heart disease and other conditions, and potentially to die prematurely — even if they exercise regularly.
久坐会带来健康隐患，这一点证据确凿。过去的研究发现，人们坐的时间越长，越有可能患上糖尿病和心脏病等疾病，甚至可能早死——即使进行有规律地锻炼。

But most of these studies were associational, meaning that they found a link between sitting and illness, but could not prove whether or how sitting actually causes ill health.
但是这些研究大多得出的是关联性结论，也就是说，它们发现久坐与患病有关，但是不能证明久坐是否的确或者如何导致健康问题。

So for the most groundbreaking of the new studies, which was published this month in the British Journal of Sports Medicine, scientists in Sweden decided to mount an actual experiment, in which they would alter the amount of time that people spent exercising and sitting, and track certain physiological results. In particular, with this experiment, the scientists were interested in whether changes in sedentary time would affect people’s telomeres.
到目前为止，新研究中最具突破性的是本月在《英国运动医学杂志》(British Journal of Sports Medicine)上发表的研究——瑞典科学家们决定进行一项实际实验，他们在实验中改变人们锻炼和静坐的时间长度，然后追踪某些生理后果。科学家们对这个实验最感兴趣的是，这些改变是否会影响人们的染色体端粒。

If you are unfamiliar with the componentry of your genes, telomeres are the tiny caps on the ends of DNA strands. They shorten and fray as a cell ages, although the process is not strictly chronological. Obesity, illness and other conditions can accelerate the shortening, causing cells to age prematurely, while some evidence suggests that healthy lifestyles may preserve telomere length, delaying cell aging.
你可能对基因的组成部分不太了解，所以我简单介绍一下，染色体端粒是DNA链条末端的小帽子。随着细胞老化，它们会缩短、磨损，不过这一过程不完全由时间决定。肥胖、疾病和其他健康问题会加速端粒缩短，导致细胞提前老化，而有些证据表明健康的生活方式能维持端粒长度，延缓细胞衰老。

For the new experiment, the Swedish scientists recruited a group of sedentary, overweight men and women, all aged 68, and drew blood, in order to measure the length of telomeres in the volunteers’ white blood cells. Then half of the volunteers began an individualized, moderate exercise program, designed to improve their general health. They also were advised to sit less.
为了这个新实验，瑞典科学家招募了一群习惯久坐的68岁超重男女，采血测量他们白细胞中端粒的长度。然后，其中一半志愿者开始个性化的适度锻炼计划，旨在提高总体健康状况。同时建议他们少坐。

The other volunteers were told to continue with their normal lives, although the scientists urged them to try to lose weight and be healthy, without offering any specific methods.
科学家们让其他志愿者继续像往常那样生活，但是鼓励他们尽量减肥，保持健康，不过没有提供具体方法。

After six months, the volunteers all returned for a second blood draw and to complete questionnaires about their daily activities. These showed that those in the exercise group were, not surprisingly, exercising more than they had been previously. But they were also, for the most part, sitting substantially less than before.
六个月后，志愿者们第二次抽血，完成关于日常活动的问卷。结果表明，锻炼组的人不出所料比从前锻炼得更多。但是他们大部分人坐的时间也比从前少了很多。