We observed a benefit threshold at approximately 3 to 5 times the recommended leisure time physical activity minimum and no excess risk at 10 or more times the minimum. In the study, researchers analyzed information from more than 660,000 people ages 21 to 98 in the United States and Sweden who answered questions about how much time they spent doing physical activity, including walking, running, swimming and bicycling. Based on self-reports of physical activity, people who did less than the recommended minimum of activity were still 20 percent less likely to die during the studies than people who were not active at all. “Our findings support the 2008 Physical Activity Guidelines for Americans, which recommend a minimum of 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity activity per week for “substantial” health benefit, and suggest “additional” benefit with more than double the exercise minimum,” said lead author Hannah Arem of the National Cancer Institute in Bethesda, Maryland. During many years of follow-up, people who did less than the minimum recommended amount of physical activity still had a considerable decrease in risk of death compared to people who did no activity at all, in a new analysis of six studies. The maximum benefit was seen among people who engaged in three to five times the recommended levels of physical activity; they were 39 percent less likely to die over the study period than people who did no exercise. In an editorial accompanying the study, Todd Manini, of the University of Florida's Department of Aging and Geriatric Research, pointed out that the people most likely to benefit from increasing the amount of exercise they do are those who do not currently do any. In a separate study, also published today in JAMA Internal Medicine, researchers in Australia found that people who engaged in vigorous activity (such as jogging or aerobics) were 9 to 13 percent less likely to die over a six-year period than those who engaged in only moderate activity (such as gentle swimming or household chores).
– If you've given up physical activity because you don't have the time or inclination to achieve recommended weekly exercise levels, strap on your walking shoes: A new study in JAMA Internal Medicine indicates that something's better than nothing in terms of increasing longevity. Scientists from the National Cancer Institute looked back at six studies and found individuals who followed the 2008 Physical Activity Guidelines of 150 minutes per week of moderate-intensity aerobic exercise—or 75 minutes of vigorous-intensity workouts—achieved "substantial" benefit, while those who doubled that baseline reaped "additional" benefit, Reuters reports. But researchers also made the significant find that those who exercised even a bit were 20% less likely to die than those who hunkered down on the couch with their remotes and did nothing. Scientists looked at 661,137 men and women (ages 21 to 98) who provided their own reports on their physical activity levels; 116,686 deaths were reported among these subjects, per the study. Those who met the guidelines saw a 31% increase in longevity over their nonactive counterparts, while participants who did three to five times the recommended levels did 39% better than the sedentary, LiveScience reports. Interestingly, exercise beyond that didn't seem to confer further benefit, but it also didn't appear to be harmful: Researchers found no link between those who worked out up to 10 times or more than the guidelines and increased death rate. A University of Florida aging specialist writes in the study's accompanying editorial that "physicians who seek out the segment of the population that performs no leisure-time physical activity could receive the most payback in their patient's health" if they recommend even a small amount of exercise. (Even a lunchtime stroll may make you feel better.)