But spending all week at a desk job did not show same link
By Maureen Salamon
WEDNESDAY, March 2, 2016 (HealthDay News) -- Playing couch potato on the weekends may be even worse for your weight than working at a desk all week, new research suggests.
Exercise scientists reported that even a 20-minute reduction in sedentary time on Saturdays and Sundays added up to a loss of more than 2 pounds and 1.6 percent of body fat after a year. But the same association was not seen with sedentary time during the weekdays.
"We know that, on average, people consume less or eat healthier diets on weekdays," explained study author Clemens Drenowatz, an assistant professor of exercise science at University of South Carolina in Columbia, S.C.
"So, they may be able to get by with less activity on weekdays because their diet makes up for it. On weekends, they're eating more, which requires more activity or less sedentary behavior to offset," Drenowatz said.
The study findings are scheduled to be presented Wednesday at an American Heart Association meeting in Phoenix. Studies presented at scientific conferences typically have not been peer-reviewed or published, and results are considered preliminary.
Much research in recent years has established an association between sedentary behavior -- which includes time sitting watching television or using computers -- with poor health outcomes, such as heart disease, diabetes, obesity and some cancers, according to the American College of Sports Medicine.
In a group of 332 adults aged 20 to 35, Drenowatz and his colleagues measured the time participants were sedentary by using a device that measured inactivity over a 10-day period. Participants also reported their own sedentary behaviors separately for weekdays and the weekend.
In addition, the study participants' body weight and body fat measurements were taken every three months over a one-year period.
"From what we saw, the overall sedentary time wasn't different on weekdays versus weekends," Drenowatz said. "A lot of people had sedentary occupations, like office jobs, and they didn't really make up for that on the weekends either. This suggests diet is the reason, though obviously more research needs to be done."