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Moderation as the Sweet Spot for Exercise(Repost)

Popularity 1Viewed 4199 times 2012-12-27 13:21 |System category:News| presented, exercise, message, perhaps


For people who exercise but fret that they really should be working out more, new studies may be soothing. The amount of exercise needed to improve health and longevity, this new science shows, is modest, and more is not necessarily better.

That is the message of the newest and perhaps most compelling of the studies, which was presented on Saturday at the annual meeting of the American College of Sports Medicine in San Francisco. For it, researchers at the University of South Carolina Arnold School of Public Health and other institutions combed through the health records of 52,656 American adults who’d undergone physicals between 1971 and 2002 as part of the Aerobics Center Longitudinal Study at the Cooper Institute in Dallas. Each participant completed physical testing and activity questionnaires and returned for at least one follow-up visit.

The researchers found that about 27 percent of the participants reported regularly running, although in wildly varying amounts and paces.

The scientists then checked death reports.

Over the course of the study, 2,984 of the participants died. But the incidence was much lower among the group that ran. Those participants had, on average, a 19 percent lower risk of dying from any cause than non-runners.

Notably, in closely parsing the participants’ self-reported activities, the researchers found that running in moderation provided the most benefits. Those who ran 1 to 20 miles per week at an average pace of about 10 or 11 minutes per mile — in other words, jogging — reduced their risk of dying during the study more effectively than those who didn’t run, those (admittedly few) who ran more than 20 miles a week, and those who typically ran at a pace swifter than seven miles an hour.

“These data certainly support the idea that more running is not needed to produce extra health and mortality benefits,” said Dr. Carl J. Lavie, medical director of cardiac rehabilitation and prevention at the Ochsner Medical Center in New Orleans and an author of the study. “If anything,” he continued, “it appears that less running is associated with the best protection from mortality risk. More is not better, and actually, more could be worse.”

His analysis echoes the results of another new examination of activity and mortality, in which Danish scientists used 27 years’ worth of data collected for the continuing Copenhagen City Heart Study. They reported that those Danes who spent one to two and a half hours per week jogging at a “slow or average pace” during the study period had longer life spans than their more sedentary peers and than those who ran at a faster pace.

This decidedly modest amount of exercise led to an increase of, on average, 6.2 years in the life span of male joggers and 5.6 years in women.

“We can say with certainty that regular jogging increases longevity,” Dr. Peter Schnorr, a cardiologist and an author of the study, said in presenting the findings at a clinical meeting organized last month by the European Association for Cardiovascular Prevention and Rehabilitation. “The good news is that you don’t actually need to do that much to reap the benefits.”

“The relationship appears much like alcohol intakes,” he continued. “Mortality is lower in people reporting moderate jogging than in non-joggers or those undertaking extreme levels of exercise.”

There’s further confirmation of that idea in the findings of a large study of exercise habits published last year in The Lancet, which showed that among a group of 416,175 Taiwanese adults, 92 minutes a week of moderate exercise, like walking, gentle jogging or cycling, increased life span by about three years and decreased the risk of mortality from any cause by about 14 percent.

In that study, those who embarked on more ambitious exercise programs did gain additional risk reduction, as seems only fair, but the benefits plateaued rapidly. For each further 15 minutes per day of moderate exercise that someone completed beyond the first 92, his or her mortality risk fell, but by only about another 4 percent.

Whether and at what point more exercise becomes counterproductive remains uncertain. “In general, it appears that exercise, like any therapy, results in a bell-shaped curve in terms of response and benefit,” says Dr. James H. O’Keefe, a cardiologist and lead author of a thought-provoking review article published on Monday in Mayo Clinic Proceedings that examines whether extreme amounts of vigorous exercise, particularly running, can harm the heart.

“To date, the data suggests that walking and light jogging are almost uniformly beneficial for health and do increase life span,” Dr. O’Keefe says. “But with more vigorous or prolonged exercise, the benefits can become questionable.

“I’m a fan of distance running,” he adds. “I run. But after about 45 to 60 minutes a day, you reach a point of diminishing returns, and at some point, you risk toxicity.”

His advice? The study by Dr. Lavie and his colleagues offers excellent guidelines for safe and effective exercise, Dr. O’Keefe says. “Twenty miles a week or less of jogging at a 10- or 11-minute-mile pace can add years to your life span. That’s very good news.” Indeed it is — especially since that routine happens to replicate almost exactly my own weekly exercise regimen.

“I wouldn’t automatically discourage people from doing more if they really want to” and are not experiencing side effects, like extreme fatigue or repeated injuries, Dr. O’Keefe continued. “But the message from the latest data is that the sweet spot for exercise seems to come with less.”

适度运动比剧烈运动对身体或许更有利


对热爱运动而又担心运动量不够的人来说,新研究得到数据也许是个好消息。锻炼运动量的多少若以提高身体素质和延长寿命为目的,新科学研究表明,适度运动效果最好,过多运动锻炼未必有益。

星期六在美国旧金山召开的美国运动学院年会上,有一篇最新、最引人注目的研究文献。它就是南卡罗来纳大学阿诺德公共卫生学院和其他有关研究机构的研究人员整理出的资料,是美国达拉斯的库珀研究所有氧运动中心1971年到2002年间纵向跟踪研究项目的52 656美国成年人健康记录。库珀研究所有氧运动中心对参与的成年人进行过体格检查、身体测试和行为问卷调查,并对他们至少进行过一次跟踪访问。

跟踪研究对象有27%人说,他们坚持有规律跑步,虽然运动量和跑步速度大有不同。

研究人员并研究分析了这些人的死亡情况。

在整个跟踪研究过程中,死亡人数有2984人。这个数字(发生率)在跑步人群中是相当低的,比不跑步的人死亡风险率降低了19% 

仔细分析过跟踪研究对象所选择运动量后,研究人员尤其发现,适度跑步对身体最有益。那些每周跑步1-20英里、平均跑步速度每英里10-11分钟的人,换句话说慢跑的人,死亡风险大大低于那些不跑步的人和那些每周跑步大于20英里以上的人(尽管公开承认很少),以及那些通常跑步速度高于每小时7英里的人。

新奥尔良Ochsner医学中心心血管医疗中心主任Carl J. Lavie博士说:“这些数据有力支持增强身体和延长寿命不必进行激烈运动的观点。” 他还说,“运动锻炼可能有利于防止疾病延长寿命,但并非运动量越大越好,而是运动量越大越有害健康。”

他的观点得到丹麦科学家一份有关运动与死亡关系的新研究报告的支持。该报告是科学家们为哥本哈根市心脏病研究课题历经27年收集的极有价值数据,每周以‘较慢速度’跑步一个小时到一个半小时丹麦人有较长寿命,远远高于久坐不动和剧烈运动的跑步者。

男子适度运动平均能延长寿命6.2岁,妇女能延长5.6岁。

“我们可确切地说,经常跑跑步有利于延长寿命。”在欧洲心血管疾病预防与修复学会上月召开的临床会议上,心脏病专家、论文作者Peter Schnorr如此说。“这个信息告诉我们,实际上,为了健康不必运动过度。”

“这种关系有点像饮酒。”他还介绍说,已见报导,适度慢跑的人比不跑步的人和运动锻炼过度的人死亡率低。”


上月发表在“柳叶刀(
The Lancet)”杂志的有关锻炼习惯调查研究的一篇文章,进一步地证实了这一论点。该文谈到在416 175台湾成年人中,每周进行92分钟适度锻炼的人,如散步、慢跑、骑自行车的人,寿命延长约三年,死亡风险降低百分之十四。



那篇调查研究报告中谈到,从事雄心勃勃锻炼计划的人死亡风险似乎得到降低,但很快就在于原歩不动,若在原每周92分钟运动锻炼基础上,每次增加15分钟,死亡率便会增加,尽管只有4%左右。



至于过度锻炼怎么会和在什么程度起到相反作用,目前仍未确定。James H. O’Keefe 博士说:“一般来说,锻炼似乎如同医疗治病一样,收益和反应是一条钟型曲线。” H. O’Keefe 博士是心脏病专家,星期一发表在梅奥临床学术会(Mayo Clinic Proceedings)上以他为第一作者的论文,引起与会者极大兴趣和讨论。该文提出了激烈运动锻炼,特别是跑步,到何种程度是否有可能伤害心脏。



“至今为止,研究结果表明,走路和轻松地跑跑步无论对身体健康,还是对延长寿命都是有好处的。” O’Keefe博士说。“但是,运动量越大、锻炼时间越长,对身体就不一定有好处。”



“我是热心长跑运动的人。”他说,“我喜爱跑步。但每天跑45-60分钟之后,锻炼收益就逐渐递减,达到某一点时甚至会造成伤害。”


他对大家提出什么劝告?


Lavie博士和他同事的研究成果为我们找到一种有效安全的极好方法。O’Keefe博士说,“每周慢跑20英里有助于健身、益寿,但速度不要超出1011分钟一英里。这无疑是个好消息。”我们几乎每个人都能正确地按这方法进行养生锻炼,这的确是特别有意义的。


“对那些有意进行大强度锻炼的人,我并非有意劝阻他们。”只要他们没有出现不良反应,如过度疲劳和意外损伤。O’Keefe说,“不过,最新调查研究数据告诉我们,适度锻炼最有利于身体健康。”

(Opinions of the writer in this blog don't represent those of China Daily.)


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Reply Report RonJaDa 2013-3-19 20:02
Thanks for your repost.  I found this article very interesting. I always knew that while walking and jogging were beneficial and running was harmful to most people (joints) I had never seen this report. It would be interesting to see a comparison between jogging and swimming as I have always been toldt he best exercise is swimming.

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  • What Makes a Good Reader 2013-3-19 20:21

    Interesting.  I have reread some books the same as watching a movie a second or third time you get something different out of it.  I knew that I would have to reread the last book I read  "Myths and Ledgends of China"   (an English translation) as it was packed full of information that would be hard to absorb with only one read.  I recommend it to anyone either learning English or on an extended stay in China.  I downloaded it from the  internet to my ereader.

  • Moderation as the Sweet Spot for Exercise(Repost) 2013-3-19 20:02

    Thanks for your repost.  I found this article very interesting. I always knew that while walking and jogging were beneficial and running was harmful to most people (joints) I had never seen this report. It would be interesting to see a comparison between jogging and swimming as I have always been toldt he best exercise is swimming.

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