Most Americans an hour more a day sitting than they used to a decade ago, a new study says.
Researchers found sitting time for adults rose from 5.5 hours per day to almost 6.5 hours and teenagers’ sitting time increased from seven hours per day to more than eight.
They also found that a quarter of Americans spent at least three hours a day lounging in front of a computer outside of school or work.
Previous studies have found that sitting too long increased the risk of obesity, heart disease, diabetes and even certain cancers.
The team, from Washington University School of Medicine in St Louis, Missouri, says its study is among the first to place specific numbers on how much time Americans actually spend sedentary and what activities they’re doing.
A new study from Washington University School of Medicine found sitting time for adults rose from 5.5 hours per day to almost 6.5 hours and, for teenagers, it rose from seven hours to eight hours (file image)
In 2018, the Department of Health and Human Services released revised physical activity guidelines and recommended less time sitting – but did not specify how much less.
For the study, published in the Journal of the American Medical Association, the team looked at data from more than 51,000 people who took part in the National Health and Nutrition Examination Survey between 2001 and 2016.
The survey, run by the Centers for Disease Control and Prevention, assesses the health and nutritional status of children and adults in the US.
Researchers found that total sitting time increased from 2007 to 2016 among teenagers (ages 12 to 19) and adults.
Teenagers’ sitting time increased from seven hours per day to more than eight hours, and adults’ sitting time rose from 5.5 hours per day to almost 6.5 hours.
‘Until now, we haven’t had data demonstrating the amount of time most Americans spend sitting watching TV or doing other sedentary activities,’ said lead author Dr Yin Cao, an epidemiologist and assistant professor of surgery at Washington University.
‘Now that we have a baseline, we can look at trends over time and see whether different interventions or public health initiatives are effective in reducing the time spent sitting and nudging people toward more active behaviors.’
Researchers found that, across age groups, up to 38 percent of those surveyed spent at least three hours per day watching television or videos, and up to 23 percent spent four hours or more doing so.
Of all the participants, black males of all age groups, who reported being obese or inactive, were the most likely to spend more time sitting to watch TV.
Additionally, computer time outside of school or work rose over the study period across all age groups.
Half of the study participants used a computer for leisure activities for at least an hour per day and a quarter used computers for three hours or more.
Co-senior author Dr Graham Colditz, an epidemiologist and the Niess-Gain Professor of Surgery at Washington University, said the team believes a lot of sedentary habits are formed early in childhood.
‘If we can make changes that help children be more active, it could pay off in the future, both for children as they grow to adulthood and for future health-care spending,’ said Dr Colditz.
‘Sedentary behavior is linked to poor health in many areas, and if we can reduce that across the board it could have a big impact.’
However, he added that creating public policies that support less time sitting can’t be implemented across the board.
‘If a neighborhood in a disadvantaged community is unsafe, for example, parents can’t just send their kids outside to play,’ Dr Colditz said.
Our environments – the way our cities, our school days and working days are designed – play roles in this behavior that are difficult to change. But at least now, we have a baseline from which to measure whether specific changes are having an impact.’