You may never win gold in the marathon but experts say you could at least walk toward better health.
Researchers say it may take far less exercise than people had thought to lower the risk of heart disease especially for the highest risk group， middle-aged men. They want to encourage people to literally take the first step.
“Doing something is better than doing nothing，” says epidemiologist① Steven N. Blair of the Institute for Aerobics Research in Dallas. “Standing is better than sitting， moving around is better than standing.”
“Lower intensity exercise brisk walking on a regular basis—provides a fair amount of benefits，” says Dr. William L. Haskell， deputy director of the Stanford Center for Research in Disease Prevention， in California.
Blair and Haskell agree that the highest-risk men are those who do virtually nothing.
Haskell says the men he studied changed their risk factors in key areas—lowering their body weight and blood pressure， while raising their HDL (High Density Lipoprotein) cholesterol， the so-called ‘good’ cholesterol that’s associated with a decreased risk of heart disease.
Haskell says his subjects did it with a program of brisk walking 30 to 40 minutes at 3.5 to 4.5 miles per hour (5.6 to 7.2 kilometers per hour) every other day. This much exercise should put your rate in the 110—125 beat per minute range or 60 percent of capacity.
That’s significantly below what experts have considered the minimum thresholds② for a training benefit to kick in 70 to 80 percent of capacity. Haskell says this range is based primarily on studies of comparatively more fit college students by researchers who wanted to detect improvement over comparatively shorter time periods.
Blair and Haskell say the training threshold concept may be misleading， because smaller doses of exercise can produce some improvement.
And， says Haskell， the prospect of having to gasp and strain their way to better health at a 70—80 percent target range has kept a lot of people from trying.
Their experient are targting at the population over age 45， using current guidelines on exercise 30 to 40 minutes at 70 to 80 percent of capacity， three times a week no more than 20 percent of men and ten percent of women meet that criterion.
The public may be thinking how little can I do and still get away with it. In fact， they may need less than they think.
And if you can’t spare 30 to 40 minutes in a lump， you can break it into 10-minute segments. By doing so， you’ll still get health benefits， and they may be nearly as great.
However， neither researcher suggests that people who are doing more should cut back. Both say there is more benefit in being more fit.
Vigorous③ exercise can relieve stress and make you better able to enjoy other kinds of outdoor sports.
High fitness in men as jogging two miles (3.2 kilometers) in less than 20 minutes， and high fitness in women as doing the same in 20 to 24 minutes.
If walking or jogging doesn’t appeal to you， then you might find some other form of aerobic exercise that can make you at least moderately fit. The goal is to live to enjoy something.
① epidemiologistn. 流行病学家
② thresholdn. 【生】【心】阈；出发点，开端，起点
③ vigorousadj. 精力充沛的；健壮的；强有力的
散步和健康
也许你永远也无法在马拉松比赛中赢得金牌，但是专家们表示，至少你可以利用散步来锻炼身体。
研究人员表示，想要减低罹患心脏病的机率，并不像一般人所认为的要做许多运动，尤其是针对高危险群的中年男人而言。他们想要鼓励人们真正走出运动的第一步。
达拉斯有氧研究机构的传染病学家，史蒂芬·布莱尔说道：“做点事总比什么都不做好，站着比坐着好，四处活动更胜于只站着不动。”
加利福尼亚州史丹佛疾病防治研究中心的副主任，威廉·哈斯卡尔博士说：“较不剧烈的运动——譬如有规律地快走——就有相当多的好处。”
布莱尔和哈斯卡尔都同意所谓高危险群就是那些从不运动的人。
哈斯卡尔说，他所研究的男性中，已改变了几个关键性的危险因素——减轻体重、血压降低，提高体内高密度脂蛋白的胆固醇，亦即有益的胆固醇。这种胆固醇能降低患心脏病的危险。
哈斯卡尔说，他的这些研究对象因为参与一项快走的训练计划而降低了患心脏病的危险，训练方法是：每隔1天花30～40分钟以3.5～4.5英里(平均每小时5～7公里左右)的速度快走，这样的运动可使你的心率每分钟跳动110～125下，或者，达到心跳极限的60%。
这个数字明显低于专家们所认为的能使任何一种训练有效的最低门坎标准，即心跳极限的70%～80%。哈斯卡尔说，这个数字是根据一些想要在短时间内就能看出运动效果的研究员，并针对比较健康的大学生所做的实验结果而定的。
布莱尔和哈斯卡尔则说这种训练门坎的观念可能有错误。因为少量的运动也能增进健康。
哈斯卡尔说一想到要达到必须在70%到80%范围之内的健康指标，就必须气喘如牛，竭尽全力地锻炼身体，许多人便望而却步。
他们的实验针对的是年龄45以上的人口，若使用目前的运动指标，即在30到40分钟内达到70%～80%的心跳率，一星期做3次。只有20%的男性和10%的女性才能达到这样的标准。”
人们可能会想能不能不做如此激烈的运动，而仍能增进健康呢？实际上，他们可能需要做的比他们所想到的还要少。
如果你不能一次花30～40分的时间来做运动，你可以10分钟一次做做运动。这样做仍然有益于健康，而且效果几乎和前者一样。
不过，两位研究员都不提倡多做运动的人要减少运动量。他们都表示愈健康者获益愈多。
激烈的运动可以消除紧张，使你更能享受其他的户外运动。
身体状况处于最佳的男性可以在20分钟内慢跑2英里（约3.2公里），健康指数为巅峰的女性约在20～24分钟跑完全程。
如果你对散步或慢跑不感兴趣，那么你也许能够做一些类似于有氧舞蹈的运动让你保持适当的健康。而最终的目标就是能活着享受一些你真正喜欢做的事。
