According to a new study sitting for long periods of time at a single stretch is linked to early death. The study explored the effects of sitting versus moving around and found that it is not only the amount of time spent sitting but also the way in which the total time spent sitting is accumulated throughout the day that counts to affect lifespan detrimentally.
The study entitled “Patterns of sedentary behavior and mortality in U.S. middle-aged and older adults: A national cohort study”, was published online in the Annals of Internal Medicine, yesterday 11th of September 2017.
The study reveals that adults who are sitting for one to two hours at a stretch without moving around are more at risk of a higher mortality rate compared to those who are sitting for the same amount of time accumulated over short bouts throughout the day. Dr. Keith Diaz, associate research scientist in the Department of Medicine at Columbia University Medical Center (CUMC) and lead investigator of the study, explained that most of us think “sedentary behavior” means the total volume of time spent sitting each day. Earlier studies have shown that sitting around either in short bouts of time or all at once, both may have negative impact on health.
For this latest study, the team used hip-mounted activity monitors on the participants. This would measure their movements while walking as well as their inactivity while sitting or lying down. The time period of study was a period of seven days.
The study was part of a major one entitled REGARDS study, a national investigation of racial and regional disparities in stroke. For this study a total of 7,985 adults over the age of 45 years were included and the participating group included fair representations from the different race and ethnicities. The participants were then followed up over an average time period of four years.
Results showed that sedentary or sitting around behavior was around 77 percent of the total waking hours of the individuals. This means over 12 hours a day are being spent being inactive. On reviewing the patterns of being inactive the team noted that 52 percent of the bouts of sitting lasted less than half an hour, 22 percent lasted between a half-hour and just under an hour, while 14 percent lasted 60 to 89 minutes and another 14 percent lasted beyond 90 minutes.
Over the follow up years, 340 of the participants died. No association was found between time spent being sedentary and its pattern and risk of death. Results revealed that those who spent over 13 hours a day being sedentary and had frequent bouts of sedentary phases that lasted at least 60 to 90 consecutive minutes at least doubled their risk of death compared to individuals who had shorter sedentary time and shorter stretches of being inactive. Those who kept their sedentary bouts to less than 30 minutes in one go had the lowest risk of death.
Dr. Diaz said that persons who require to sit for longer periods of time because their jobs or lifestyles demanded so, need to get up and move about every half an hour. Although the team at present cannot quantify the exact amount of activity a person who is moving around every half an hour should adopt, Diaz emphasized that this minor behavior change could lower the risk of death. He noted that this was one of the largest studies that linked sitting and inactive time with risk of death.
Study co-author Monika Safford, chief of the Division of General Internal Medicine at Weill Cornell Medicine, and an internist at NewYork-Presbyterian/Weill Cornell Medical Center said that this study proves what was suspected about how dangerous long bouts of sitting can be. She called sitting around the “new smoking”. She said that creative ways could be devised to interrupt periods of sitting with “bursts of activity”.
The study was supported by the National Institutes of Health and the Coca-Cola Company.