Cutting daily sitting time to under 3 hours might extend life by 2 years

July 9, 2012

Restricting the amount of time spent seated every day to less than 3 hours might boost the life expectancy of US adults by an extra 2 years, indicates an analysis of published research in the online journal BMJ Open.

And cutting down TV viewing to less than 2 hours every day might extend life by almost 1.4 years, the findings suggest.

Several previous studies have linked extended periods spent sitting down and/or to , such as diabetes and death from /stroke.

The researchers used data collected for the National Health and (NHANES) for 2005/6 and 2009/10, to calculate the amount of time US adults spent watching TV and sitting down on a daily basis.

NHANES regularly surveys a large of the US population on various aspects of their health and lifestyle.

They trawled the research database MEDLINE, looking for published studies on sitting time and deaths from all causes, and pooled the different relative risk data from the five relevant studies, involving almost 167,000 adults. The database was then reanalysed, taking account of age and sex.

They combined these data and the NHANES figures to come up with a population attributable fraction (PAF) - an estimate of the theoretical effects of a risk factor at a population, rather than an individual level - to calculate the number of deaths associated with time spent sitting down.

The PAFs for deaths from all causes linked to sitting time and TV viewing were 27% and 19%, respectively.

The results of life table analyses indicates that cutting the amount of time spent sitting down every day to under three hours would add an extra two years to life expectancy.

Similarly, restricting time spent watching TV to under two hours daily would extend life expectancy by an extra 1.38 years.

The authors emphasise that their analysis assumes a causal association rather than proving that there is one. But they point to the evidence showing the detrimental effect of a sedentary lifestyle on health.

And they caution that their findings should not be interpreted as meaning that someone who leads a more sedentary lifestyle can expect to live two or 1.4 years less than someone who is more active.

"The results of this study indicate that extended and TV viewing may have the potential to reduce life expectancy in the USA," they write.

"Given that the results from objective monitoring of sedentary time in NHANES has indicated that adults spend an average of 55% of their day engaged in sedentary pursuits, a significant shift in behaviour change at the population level is required to make demonstrable improvements in ," they conclude.

Further research will be required before recommendations on safe levels of sedentary behaviour can be made, they add.

Explore further: Daily TV quota of 6 hours could shorten life expectancy by 5 years

More information: Sedentary behaviour and life expectancy in the USA: a cause-deleted life table analysis, doi:10.1136/bmjopen-2012-000828

Related Stories

Daily TV quota of 6 hours could shorten life expectancy by 5 years

August 16, 2011
Watching TV for an average of six hours a day could shorten the viewer's life expectancy by almost five years, indicates research published online in the British Journal of Sports Medicine.

Diabetes risk from sitting around

March 2, 2012
A new study has found that women who stay seated for long periods of time every day are more prone to developing type 2 diabetes, but that a similar link wasn't found in men.

Prolonged TV viewing linked to increased risk of type 2 diabetes, cardiovascular disease

June 14, 2011
Watching television is the most common daily activity apart from work and sleep in many parts of the world, but it is time for people to change their viewing habits. According to a new study from Harvard School of Public ...

TV viewing poses greater risk than computer use for cardiovascular disease

November 16, 2011
Physical activity will definitely lower children's chances of developing cardiovascular disease down the road, but physical inactivity will not necessarily increase it. Findings from a recent Queen's University study shows ...

Recommended for you

Poor sleep could lead to heavier drinking in young adults, study finds

December 8, 2017
A shortened night of sleep may increase young adults' risk of heavier drinking, according to a new Yale study that assessed reciprocal variations in sleep and drinking over time in young adults.

Researchers say nutritional labeling for sodium doesn't work

December 8, 2017
Potato chips, frozen pizza, a fast food hamburger-these foods are popular in the American diet and saturated with sodium. Though eating too much can lead to high blood pressure and heart disease, 90 percent of Americans eat ...

Observation care may save more than thought

December 8, 2017
In the world of health care spending policy, it usually works that as Medicare goes so goes private insurance on matters of managing the cost and quality of care.

Screen time before bed linked with less sleep, higher BMIs in kids

December 7, 2017
It may be tempting to let your kids stay up late playing games on their smartphones, but using digital devices before bed may contribute to sleep and nutrition problems in children, according to Penn State College of Medicine ...

Mindful yoga can reduce risky behaviors in troubled youth, says research

December 7, 2017
For some young people, dealing with life stressors like exposure to violence and family disruption often means turning to negative, risky behaviors—yet little is known about what can intervene to stop this cycle.

Teen girls 'bombarded and confused' by sexting requests: study

December 7, 2017
Adolescent women feel intense pressure to send sexual images to men, but they lack the tools to cope with their concerns and the potential consequences, according to new Northwestern University research published Wednesday, ...

0 comments

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.