New research: Moving for just 15 minutes a day can save your life
S. L. Baker
That's the dramatic conclusion of a study just published in the online version of The Lancet . Dr. Chi-Pang Wen of the National Health Research Institutes in Taiwan and China Medical University Hospital, and Dr. Jackson Pui Man Wai of the National Taiwan Sport University, headed a research team that investigated a large range of physical activity levels to see just how much exercise produces important health benefits. Previous research has come up with unclear results about whether exercising less than 150 minutes a week can help you live longer.
The new study involved over 400,000 Taiwanese people who participated in standard medical screening in Taiwan between 1996 and 2008, with an average follow-up of 8 years. Based on how much the research subjects said they exercised each week, the study participants were placed into one of five categories of exercise: virtually no exercise (inactive), or low, medium, high, or very high physical activity. Next, the scientists calculated hazard ratios (HR), a statistical measurement used to figure out the odds of an event occurring within a group at a particular time, to see what the risk of death was for every group that was active compared with the inactive group. Then the research team calculated life expectancy for each research participant group.
The results? Compared with individuals in the inactive group, those who were active had dramatic health benefits. Even the research participants in the low activity group who only exercised for an average of 92 minutes per week (about 15 minutes a day) had a 14 percent reduced risk of all-cause mortality, a 10 percent reduced risk of dying from any type of cancer and, on average, a three year longer life expectancy.
What's more, every additional 15 minutes of exercise each day beyond the minimum amount reduced death from all causes by another four percent and reduced death from cancer by another by one percent. These benefits were found across all age groups and among both men and women. The benefits were even applicable to the people with risks for cardiovascular disease. On the other hand, those in the inactive group who had a 17 percent increased risk of mortality compared with individuals in the low exercise group.
"In Taiwan, if inactive individuals engage in low-volume daily exercise, one in six deaths from all causes could be prevented," the scientists said in a statement to the media. "If the minimum amount of exercise we suggest is adhered to, mortality from heart disease, diabetes, and cancer could be reduced. This low volume of physical activity could play a central part in the global war against non-communicable diseases, reducing medical costs and health disparities."
In commentary about the study, Dr. Anil Nigam and Dr. Martin Juneau of the Montreal Heart Institute and Universite de Montreal in Quebec, Canada stated: "The knowledge that as little as 15 minutes per day of exercise on most days of the week can substantially reduce an individual's risk of dying could encourage many more individuals to incorporate a small amount of physical activity into their busy lives. Governments and health professionals both have major roles to play to spread this good news story and convince people of the importance of being at least minimally active."
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Aug. 16, 2011