Adults who watch TV three hours or more daily may double their risk of premature death compared to those who watch less, according to a new study.

“Television viewing is a major sedentary behavior and there is an increasing trend toward all types of sedentary behaviors,” said Miguel Martinez-Gonzalez, M.D., Ph.D., M.P.H., the study’s lead author and professor and chair of the Department of Public Health at the University of Navarra in Pamplona, Spain. “Our findings are consistent with a range of previous studies where time spent watching television was linked to mortality.”

Researchers determined the association between the time spent watching TV, using a computer, or driving, and the risk of death from all causes.  They followed more than 13,000 healthy Spanish university graduates, average age 37, for a median of 8.2 years. During the study, 19 died from cardiovascular causes, 46 from cancer and 32 from other causes.

The risk of early death was twice as high for people who said they watched three or more hours of TV a day versus those who watched one or fewer hours, even after adjusting for other factors related to higher death risks.

Researchers found no significant association between computer or driving time and premature death.

“As the population ages, sedentary behaviors will become more prevalent, especially watching television, and this poses an additional burden on the increased health problems related to aging,” Martinez-Gonzalez said. “Our findings suggest adults may consider increasing their physical activity, avoid long sedentary periods, and reduce television watching to no longer than one to two hours each day.”

The study, published in the Journal of the American Heart Association, cited previous research that suggested that half of U.S. adults have sedentary lives.

The American Heart Association recommends at least 150 minutes of moderate-intensity aerobic activity, or at least 75 minutes of vigorous aerobic activity per week. It also recommends moderate- to high-intensity muscle-strengthening at least two days a week.

For more information: