Is 15 minutes of exercise a day to get your heart rate up better than nothing? Yes... by a long shot! A new study shows that it actually decreases your risk of death, and extends life expectancy.
LOS ANGELES (AP) -- Don't despair if you can't fit in the recommended 30 minutes of daily exercise. Growing evidence suggests that even half that much can help.
It's still no excuse to slack off. Regular exercise strengthens muscles, reduces the risk of some diseases and promotes mental well-being. The more exercise, the better.
But not everyone has the time or willpower. So researchers set out to find the minimum amount of physical activity needed to reap health benefits. The findings by a study in Taiwan suggest just 15 minutes of moderate exercise a day can lead to a longer life.
This "may convince many individuals that they are able to incorporate physical activity into their busy lives," Dr. Anil Nigam of the University of Montreal said in an email. Nigam had no role in the research but wrote an editorial accompanying the Taiwan study published online Monday in The Lancet.
Fitness guidelines by the World Health Organization, the U.S. and other countries recommend that adults get at least a half-hour of moderate workout most days of the week. This can include brisk walking, bike riding and water aerobics.
Realizing that it might be difficult for some to break a sweat, health groups have suggested breaking it down into smaller, more manageable chunks of time such as three 10-minute spurts a day on weekdays.
The latest study, a large one led by researchers at the National Health Research Institutes in Taiwan, sought to determine if exercising less than the recommended half-hour was still helpful.
The study found those who exercised just 15 minutes a day – or 90 minutes a week – cut their risk of death by 14 percent and extended their life expectancy by three years compared with those who did no exercise. Both men and women benefited equally from the minimum activity.
Each additional 15 minutes of exercise reduced the risk of death by another 4 percent compared with the inactive group. Researchers did not report how additional exercise affected life expectancy.
There were some limitations. Answers were self-reported. The study, though large, was observational, which means the health benefits may not be entirely due to exercise. But researchers said they took into account other factors that might affect health such as smoking and drinking. And outside scientists said the findings are in line with other studies.
For the sedentary, the key is this: Some exercise is better than none.
Read More: http://www.huffingtonpost.com/2011/08/16/15-minutes-daily-exercise-live-longer_n_928137.html
Monday, January 23, 2012 at 1:56PM 
Berlin (dpa) - Taking a minimum of 15 minutes of exercise a day can extend life expectancy by up to three years, according to Germany's Society of Neurologists and the Stroke Society.