Sitting around watching TV or playing internet games also called “Screen time,” as defined by time spent watching television or using electronic devices for leisure activities such as video games.
A study, published in the August 25, 2011, issue of BMC Public Health,evaluated the amount of time among Belgian adults spent in front of the TV or computer. The study found that the average amount of screen time was 3 hours a day. Factors associated with more screen time included older age, higher body mass index, and a belief that television viewing was not harmful. Larger television sets were also more likely to be watched more often.
However, adults with higher educational levels spent more leisure time on the Internet but less time in front of a television. Also more computers in the home was associated with more Internet screen time. Overall, the associations between sociodemographic variables and total screen time were similar among men and women.
The January 20,2015 issue of the Annals of Internal Medicine found that sitting was associated with higher mortality from all causes, as well as increased incidence of cancer, cardiovascular disease, and type 2 diabetes, even among people who exercise regularly.
The study analysis confirmed 47 previously published articles that showed an association between all-cause mortality and sedentary behavior is greatest among people who exercise the least.
The all-cause mortality was 30% lower for those that exercised compared to those with low levels of physical activity.
A large European study published in the American Journal of Clinical Nutrition showed that inactivity contributed to twice as many deaths as obesity. In the study participants benefited from as little as 20 minutes of exercise daily, or just more than 2 hours a week.
A study of women aged 50 to 79 years published in the Journal of the American College of Cardiology found that low or moderate exercise levels failed to reverse the effect of sitting for long periods every day. Moderate exercise was defined as participating in 2 to 2.5 hours of exercise weekly. However, women who walked 7 hours each week or ran or jogged for 5 hours each week did not experience increased risk from an otherwise sedentary lifestyle.
Authors of an editorial that accompanied the Annals of Internal Medicine study said research about sedentary behavior still has not led to specific guidelines about how to best modify sitting practices.