Long sitting periods may be just as harmful as daily total

September 11, 2017, Columbia University Medical Center
Credit: CC0 Public Domain

A new study finds that it isn't just the amount of time spent sitting, but also the way in which sitting time is accumulated during the day, that can affect risk of early death.

The study, published online today in Annals of Internal Medicine, found that adults who sit for one to two hours at a time without moving have a higher mortality rate than adults who accrue the same amount of in shorter bouts.

"We tend to think of sedentary behavior as just the sheer volume of how much we sit around each day," said Keith Diaz, PhD, associate research scientist in the Department of Medicine at Columbia University Medical Center (CUMC) and lead investigator of the study. "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."

The researchers used hip-mounted activity monitors to objectively measure inactivity during waking time over a period of seven days in 7,985 black and white adults over age 45. (The participants were taking part in the REGARDS study, a national investigation of racial and regional disparities in stroke.)

On average, sedentary behavior accounted for 77 percent of the participants' waking hours, equivalent to more than 12 hours per day. Over a median follow-up period of four years, 340 of the participants died. Mortality risk was calculated for those with various amounts of total sedentary time and various sedentary patterns. Those 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 with those who had the least total sedentary time and the shortest sedentary bouts.

The researchers also found that participants who kept most of their sitting bouts to less than 30 minutes had the lowest risk of death. "So if you have a job or lifestyle where you have to sit for prolonged periods of time, we suggest taking a movement break every half hour. This one behavior change could reduce your risk of death, although we don't yet know precisely how much activity is optimal," Dr. Diaz said.

The study was the largest to link objectively measured sedentary time and sedentary patterns with .

"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 and the John J. Kuiper Professor at Weill Cornell Medicine, and an internist at NewYork-Presbyterian/Weill Cornell Medical Center. "We need creative ways to ensure that we not only cut back on the total amount we sit, but also increase regular interruptions to sitting with bursts of activity." Dr. Safford is the PI on one of the REGARDS ancillary studies and provided the cardiac events data for this paper.

The study is titled, "Patterns of and mortality in U.S. middle-aged and older adults: A national cohort study."

Explore further: Structured physical activity results in small reduction in sedentary time among older adults

More information: Abstract: annals.org/aim/article/doi/10.7326/M17-0212

Editorial: annals.org/aim/article/doi/10.7326/M17-2181

Related Stories

Structured physical activity results in small reduction in sedentary time among older adults

July 18, 2017
In older adults with mobility impairments, long-term, moderate-intensity physical activity was associated with a small reduction in total sedentary time, according to a study published by JAMA.

Middle-aged found to be as sedentary as pensioners

June 27, 2017
Most middle-aged office workers now spend as much time sitting down as older pensioners, according to a report.

Sedentary behavior increases risk of death for frail, inactive adults

August 21, 2017
Sedentary time, for example, time spent sitting, increases the risk of death for middle-aged and older people who are frail and inactive, but does not appear to increase the risk for nonfrail people who are inactive, according ...

Study assesses amount, patterns of sedentary behavior of older women

December 17, 2013
Among 7,000 older women who wore an accelerometer to measure their movement, about two-thirds of their waking time was spent in sedentary behavior, most of which occurred in periods of less than 30 minutes, according to a ...

Only 20 minutes less sitting per day is enough to maintain good health and muscle mass

August 30, 2017
Finnish researchers conducted one of the largest and longest studies to find out if it is possible to reduce sedentary time and if the reduction will result in any health benefits during one year. A tailored counseling helped ...

More TV & less physical activity ramps up risk of walking disability

August 30, 2017
Older people who watched more than five hours of TV per day and reported three or fewer hours per week of total physical activity had more than a three-fold higher risk of being unable to walk or having difficulty walking ...

Recommended for you

Sweet, bitter, fat: New study reveals impact of genetics on how kids snack

February 22, 2018
Whether your child asks for crackers, cookies or veggies to snack on could be linked to genetics, according to new findings from the Guelph Family Health Study at the University of Guelph.

The good and bad health news about your exercise posts on social media

February 22, 2018
We all have that Facebook friend—or 10—who regularly posts photos of his or her fitness pursuits: on the elliptical at the gym, hiking through the wilderness, crossing a 10K finish line.

Smartphones are bad for some teens, not all

February 21, 2018
Is the next generation better or worse off because of smartphones? The answer is complex and research shows it largely depends on their lives offline.

Tackling health problems in the young is crucial for their children's future

February 21, 2018
A child's growth and development is affected by the health and lifestyles of their parents before pregnancy - even going back to adolescence - according to a new study by researchers at the Murdoch Children's Research Institute, ...

Lead and other toxic metals found in e-cigarette 'vapors': study

February 21, 2018
Significant amounts of toxic metals, including lead, leak from some e-cigarette heating coils and are present in the aerosols inhaled by users, according to a study from scientists at Johns Hopkins Bloomberg School of Public ...

Why teens need up to 10 hours' sleep

February 21, 2018
Technology, other distractions and staying up late make is difficult, but researchers say teenagers need to make time for 8-10 hours of sleep a night to optimise their performance and maintain good health and wellbeing.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

VOR_
not rated yet Sep 13, 2017
delet

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.