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Getting off the couch may lead to longer life

Inactive adults might prolong their lives just by getting off the couch for an hour a day, a new U.S. study suggests.

(Reuters Health) - Inactive adults might prolong their lives just by getting off the couch for an hour a day, a new U.S. study suggests.

The research team, which documented the harmful effects of being sedentary a few years ago, has now analyzed the health benefit of replacing couch time with any kind of activity.

For less active adults, replacing one hour of sitting per day with an equal amount of time moving around - exercising, or even just performing activities of everyday living - was linked with a significantly lower risk of death, study leader Charles Matthews told Reuters Health in an email.

For people who were more active to start with, however, "only the replacement of sitting time with purposeful exercise was associated with lower mortality, perhaps because their baseline level of physical activity was already adequate," said Matthews, a researcher with the National Cancer Institute in Bethesda, Maryland.

Less than a third of Americans over age 65 are physically active enough to meet the 2008 Physical Activity Guidelines for Americans, which recommend at least 150 minutes a week of moderate-intensity physical activity like brisk walking.

Many spend nine or more hours per day - not including sleep - being sedentary, Matthew and his colleagues write in Medicine and Science in Sports and Exercise.

To follow up on their previous research, which showed a higher risk of death from any cause, and particularly from heart-related causes, with more time being sedentary, the researchers decided to look at how much and what kinds of activity would be needed to lower mortality risks. They were especially interested in whether activity short of a full gym workout would still offer a benefit.

They analyzed data on more than 150,000 healthy adults who were between 59 and 82 years old when they entered the NIH-AARP Diet and Health Study. All were free of any major illness at the start of the study.

During follow-up for an average of almost seven years, a little over 12,200 participants died. People who were sedentary for less than five hours a day had a 20 to 40 percent lower risk of death than people with more than 12 sedentary hours a day.

People who spent one to two hours a day doing non-exercise activities like house cleaning or yard work were significantly less likely to die compared to people with little or no physical activity. For men, the risk fell by 30 percent, and for women, by 50 to 60 percent.

Next, the authors used a statistical technique to calculate the value of each hour of activity that replaced sitting time and found that people who were most sedentary got the most out of adding any kind of activity.

For people with less than two hours a day of activity, adding one hour of exercise reduced risk of death by 42 percent, and adding one hour of non-exercise activity yielded a 30 percent risk reduction.

In contrast, the most active people only got a 10 percent drop in mortality risk with each hour of added exercise, and no value out of added non-exercise activity.

"Our findings provide evidence to support physicians in counseling their older patients to reduce their sedentary time in favor of more physically active pursuits," Matthews said. In particular, he added, doctors might want to encourage patients to reduce TV time.

"Television viewing consumes more than half of the leisure-time for most older adults, Matthews said. "Trading TV time for exercise or other physically active pursuits may help extend longevity."

Dr. Matthew Bartels of Montefiore Medical Center in New York said the study confirms that being sedentary is not as healthy as being generally active.

"This study gives us the evidence to say that not only is that good advice, but it's critical to be more active. And the activity that helps you doesn't have to be a formal exercise program," said Bartels, who was not involved in the research.

"I find this to be a very exciting study, and the real thing I'm hoping we can get across to people is that they need to be more active," he said. "The take-home is to get off your chair."

Matthews said that people who want to make changes and reduce sitting time can start with shorter amounts of time (10 or 15 minutes), especially if they are just starting to exercise.

"Build up your active time gradually," Matthews said. "Try and identify several different types of sedentary behavior to change so that you can do a variety of activities on different days."

SOURCE: Medicine and Science in Sports and Exercise, online January 26, 2015.