August 16th, 2011
11:44 AM ET
Even a little exercise – about 15 minutes a day - can translate to health benefits, according to an observational study from Taiwan.
Researchers from Taiwan’s National Health Research Institutes found that individuals who exercised an average of 92 minutes a week had 14 percent reduced mortality compared with inactive people. This extended to three more years of life expectancy, according to the study published in the Lancet.
The authors surveyed 416,175 people who self-assessed how much they exercised. Participants were asked to recall the examples of exercises they did the previous month such as walking, brisk walking, jogging or running, which were categorized into inactive, low, medium, high or very high activity.
Most of the participants, 54% were inactive. In the findings, 22% identified as low, 14% as medium, and 5% each for high and very high activity levels.
They followed up with participants after an average of eight years to calculate mortality risk and life expectancy for each category. Researchers found that even 15 minutes of moderate intensity exercise “had significant health benefits when compared with individuals who were inactive,” according to the study.
People who exercised had less deaths and less cancer-related deaths than inactive individuals. “In Taiwan, if inactive individuals engage in low-volume daily exercise, one in six all-cause deaths could be postponed,” wrote lead author, Dr. Chi Pang Wen.
The World Health Organization's exercise guidelines recommend exercising at least 30 minutes, five days a week. But busy schedules, lifestyle and other reasons prevent people from getting that amount of activity.
“Individuals are more likely to do 15 minutes of daily exercise than they are 30 minutes of daily exercise,” the authors wrote.
Basically, a little exercise is better than nothing. And more is better.
But the study was an observational study, so it’s impossible to determine that the health outcomes were entirely due to exercise. Plus, the exercise behaviors were self-reported, which may not always be accurate.
“Because of its observational nature, Wen and colleagues’ study cannot establish causality, but their results are entirely consistent” with previous findings regarding exercise," wrote Anil Nigam of the Montreal Heart Institute and Martin Juneau of Université de Montréal in an accompanying commentary in the Lancet. Common causes of death such as cancer and heart disease are related to poor nutrition, inflammation and physical inactivity.
“If the minimum amount of exercise we suggest is adhered to, mortality from heart disease, diabetes, and cancer could be reduced,” wrote the study authors.
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