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Multiple studies have warned about the health risks of sitting too much. Hours spent sitting, whether at desks or in front of the television, have been linked to increased odds of cardiovascular disease, type 2 diabetes and kidney problems. But modern life can make it difficult to stay out of chairs, and alternatives such as “standing desks” don’t appeal to everyone.
A new study may offer hope to sedentary sitters: Using data on more than 3,600 adults, researchers found that brief periods of simply walking around the room substantially reduced mortality risk among people who spent long periods sitting. As little as two minutes of gentle walking per hour was associated with a 33% lower risk compared to non-stop sitting.
“We know that exercise is good for us and yet, despite this, our society has become more sedentary than ever,” says Miriam E. Nelson, PhD, associate dean of the Tisch College and a professor in Tufts’ Friedman School, author of the “Strong Women” series of books. “We are built to move, and when our bodies move on a regular basis, they are healthy; when they don’t, when we’re largely sedentary, our bodies deteriorate.”
MEASURING MOVEMENT: In the study, published in the Clinical Journal of the American Society of Nephrology, Srinivasan Beddhu, MD, of the University of Utah, and colleagues analyzed data from the annual National Health and Nutrition Examination Survey (NHANES). In recent surveys, selected participants have supplemented their questionnaire answers by wearing activity monitors called accelerometers; this gives a more accurate record of a person’s movements than depending on individual recall. Most of the participants were generally healthy, although a subgroup of 383 people had chronic kidney disease.
Researchers divided participants into four groups based on minutes per hour of different levels of accelerometer activity: sedentary/sitting, low (such as standing up but not walking around much), light (such as strolling around a room or walking into another room), and moderate/vigorous (jogging or other exercise). The study then compared activity levels to records of deaths three or four years after the assessment.
ADDITIVE ACTIVITY: There was little difference in mortality between the sedentary and low-activity groups. But people who interrupted their sitting with light activity were at significantly lower mortality risk than those who were completely sedentary; this difference was even sharper among the kidney-disease subgroup (41%). As little as two minutes an hour of light activity was enough to be associated with lower risk.
Boosting activity levels to moderate/vigorous further reduced risk, but the number of such active participants was too low to be statistically significant. Adding additional minutes of light activity, however, did make a significant difference. Getting up from your chair for two minutes or five minutes more light activity rather than sitting time, Dr. Beddhu said, could further reduce risk of premature death.
He cautioned that the study was observational, and so can’t prove cause and effect. And Tufts’ Nelson notes that a quick break from your chair is no substitute for regular physical activity. But if you’ve been worried about the health risks of sitting too much, apparently every little bit helps.