beanlicker
03-19-2014, 05:29 PM
http://www.menshealth.com/sites/default/files/2014/03/ExerciseSitting.jpg
Over the last few years, emerging research has suggested that sitting for long hours every day—like most people do at work—increases your risk for heart disease, diabetes, and early death. And this was shown to be true even if you engaged in regular physical activity.
In fact, in a Men’s Health feature back in 2010, titled Sentenced to the Chair (http://my.menshealth.com/exclusive-content/sentenced-chair), we reported that:
“. . . the amount of time you exercise and the amount of time you spend on your butt are completely separate factors for heart-disease risk. New evidence suggests, in fact, that the more hours a day you sit, the greater your likelihood of dying an earlier death regardless of how much you exercise or how lean you are.”
This news was troubling to us, and to gym-goers everywhere. It also bothered Mark Peterson, Ph.D., M.S., assistant research professor of the University of Michigan School of Medicine.
“I thought, ‘Could this really be true?' ” says Peterson. “Is it possible that sedentary time is trumping my exercise time?”
Peterson works out for about an hour to 90 minutes most mornings, but then often spends the rest of his day planted in a chair, followed by another couple of hours of downtime in the evening—relaxing with his wife and kids.
So he decided to dig into the research himself. “It was personal for me,” says Peterson, who’s not only an expert in exercise science, but also has a master’s degree in biostatistics. Read: He knows how to crunch numbers.
“What I found is that even though the studies were extremely well-conducted, they didn’t necessarily tell the whole story,” says Peterson. “In many cases, the data were gathered with questionnaires, and people were simply asked if they exercised on a certain day or not. There wasn’t an accurate way to account for the intensity or duration of that exercise. And it was usually a totally subjective measure,” says Peterson.
The upshot is that if a person went for a casual 10-minute walk, it counted the same as if he did 45 minutes of intense interval training. “As a result, exercise wasn’t found to have any impact on the increased disease risks associated with being sedentary.”
Peterson decided to see what would happen if you actually accounted for exercise intensity. He pulled data from the National Health and Nutrition Examination Survey (NHANES), an ongoing study that provides detailed physical activity data for thousands of people across multiple years.
“The NHANES data provides objective measures of activity with accelerometers,” says Peterson. “So we knew how hard and how long the people were exercising. And we looked at different levels, over several years: light, moderate, and vigorous activity, as well different combinations.”
The finding: People who did the highest amount of moderate and vigorous activity a day weren’t at any increased risk for heart disease or diabetes, regardless of how much sedentary time they logged. “As long as they were exercising hard and regularly, it didn’t matter if they also had a lot of sedentary behavior,” says Peterson.
The magic number for the protective effect, based on this research, appears to be a minimum of 30 to 45 minutes a day of moderate to vigorous activity, at least five days a week. “For cardiovascular exercise, that equates to anything over 70 percent of your max heart rate,” says Peterson. “The type of exercise you do doesn’t necessarily matter, and it can be done all at once, or even accumulated in shorter bouts throughout the day.”
Peterson notes that these particular study results may not be relevant to an older adult population or people with mobility restrictions. But he also wants to be clear: “Reducing sedentary time is still a very important public health message. We should all try to move more, and sit less,” says Peterson. “But it shouldn’t be oversold, and the benefits of moderate to vigorous daily exercise shouldn’t be undersold.”
Over the last few years, emerging research has suggested that sitting for long hours every day—like most people do at work—increases your risk for heart disease, diabetes, and early death. And this was shown to be true even if you engaged in regular physical activity.
In fact, in a Men’s Health feature back in 2010, titled Sentenced to the Chair (http://my.menshealth.com/exclusive-content/sentenced-chair), we reported that:
“. . . the amount of time you exercise and the amount of time you spend on your butt are completely separate factors for heart-disease risk. New evidence suggests, in fact, that the more hours a day you sit, the greater your likelihood of dying an earlier death regardless of how much you exercise or how lean you are.”
This news was troubling to us, and to gym-goers everywhere. It also bothered Mark Peterson, Ph.D., M.S., assistant research professor of the University of Michigan School of Medicine.
“I thought, ‘Could this really be true?' ” says Peterson. “Is it possible that sedentary time is trumping my exercise time?”
Peterson works out for about an hour to 90 minutes most mornings, but then often spends the rest of his day planted in a chair, followed by another couple of hours of downtime in the evening—relaxing with his wife and kids.
So he decided to dig into the research himself. “It was personal for me,” says Peterson, who’s not only an expert in exercise science, but also has a master’s degree in biostatistics. Read: He knows how to crunch numbers.
“What I found is that even though the studies were extremely well-conducted, they didn’t necessarily tell the whole story,” says Peterson. “In many cases, the data were gathered with questionnaires, and people were simply asked if they exercised on a certain day or not. There wasn’t an accurate way to account for the intensity or duration of that exercise. And it was usually a totally subjective measure,” says Peterson.
The upshot is that if a person went for a casual 10-minute walk, it counted the same as if he did 45 minutes of intense interval training. “As a result, exercise wasn’t found to have any impact on the increased disease risks associated with being sedentary.”
Peterson decided to see what would happen if you actually accounted for exercise intensity. He pulled data from the National Health and Nutrition Examination Survey (NHANES), an ongoing study that provides detailed physical activity data for thousands of people across multiple years.
“The NHANES data provides objective measures of activity with accelerometers,” says Peterson. “So we knew how hard and how long the people were exercising. And we looked at different levels, over several years: light, moderate, and vigorous activity, as well different combinations.”
The finding: People who did the highest amount of moderate and vigorous activity a day weren’t at any increased risk for heart disease or diabetes, regardless of how much sedentary time they logged. “As long as they were exercising hard and regularly, it didn’t matter if they also had a lot of sedentary behavior,” says Peterson.
The magic number for the protective effect, based on this research, appears to be a minimum of 30 to 45 minutes a day of moderate to vigorous activity, at least five days a week. “For cardiovascular exercise, that equates to anything over 70 percent of your max heart rate,” says Peterson. “The type of exercise you do doesn’t necessarily matter, and it can be done all at once, or even accumulated in shorter bouts throughout the day.”
Peterson notes that these particular study results may not be relevant to an older adult population or people with mobility restrictions. But he also wants to be clear: “Reducing sedentary time is still a very important public health message. We should all try to move more, and sit less,” says Peterson. “But it shouldn’t be oversold, and the benefits of moderate to vigorous daily exercise shouldn’t be undersold.”