In this modern age of computers and TV, more and more people are finding themselves sitting for extended periods of time in front of a screen. We have recognized that prolonged sitting for most of our days can have some negative effects on our health, so we try to get up every so often to stretch our legs and get our blood circulating. But according to a new study, it isn’t just the amount of time we spend sitting that’s the problem, but also the way sedentary time accumulates during the day that significantly contributes to our risk of death.
A research team from the Columbia University Medical Center (CUMC) found that adults who sit for one to two hours at a time without moving have a higher risk dying (mortality rate) than adults who sit for an equal amount of time but in shorter bouts.
“We tend to think of sedentary behavior as just the sheer volume of how much we sit around each day. But previous studies have suggested that sedentary patterns—whether an individual accrues sedentary time through several short stretches or fewer long stretches of time—may have an impact on health,” said Keith Diaz, PhD, associate research scientist in the Department of Medicine at CUMC and lead investigator of the study.
The researchers studied the sedentary behavior of nearly 8,000 participants who were over age 45 and either black or white. A hip-mounted activity monitor was given to each person to track inactivity during waking times.
Once the study had concluded, they found that sedentary behavior accounted for 77 percent of participants’ waking hours. This was equivalent to more than 12 hours per day. During a median follow-up period of four years, 340 people died.
What was interesting was that those participants with the greatest amount of sedentary time (more than 13 hours per day) and who frequently had sedentary bouts of at least 60 to 90 consecutive minutes had a nearly two-fold increase in death risk, compared to those who had the least sedentary time and shortest sedentary bouts.
Those who were sedentary for less than 30 minutes at a time had the lowest risk of death, according to the researchers.
This finding compelled the team to suggest that anyone who leads a sedentary lifestyle and sits for extended periods of time should take a movement break every half-hour. A change this simple could reduce the risk of death, but admittedly researchers don’t know how much activity is optimal.
“This study adds to the growing literature on how dangerous long periods of sitting are for our health, and underscores a growing awareness among clinicians and researchers that sitting really is the new smoking,” said study co-author Monika Safford, MD, chief of the Division of General Internal Medicine at Weill Cornell Medicine.