Adults who watch too much television increase their risk of dying prematurely, a new study suggests.

Spanish researchers looked at over 13,200 healthy adults, with an average age of 37. They wanted to determine if there were any links between three types of sedentary behaviour and premature death. The three types of sedentary behaviour were watching television, using a computer and driving.

The participants were monitored for an average of eight years, during which time, almost 100 of them died.

The study found that those who watched television for three hours or more each day had double the risk of dying prematurely compared to those who watched for one hour or less per day.

This two-fold increased risk remained even when other factors which can influence premature death were taken into account.

"Television viewing is a major sedentary behavior and there is an increasing trend toward all types of sedentary behaviors. Our findings are consistent with a range of previous studies where time spent watching television was linked to mortality," commented the study's lead author, Dr Miguel Martinez-Gonzalez, of the University of Navarra in Pamplona.

The study found no significant link between premature death and the time spent using a computer or driving.

Dr Martinez-Gonzalez noted that as the population gets older, sedentary behaviours ‘will become more prevalent, especially watching television'.

"This poses an additional burden on the increased health problems related to aging. 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," he said.

Adults are recommended to undertake moderate-intensity aerobic exercise, such as brisk walking, for 150 minutes per week. This can be broken down into smaller time periods, such as 30 minutes per day, five days a week.

Details of these findings are published in the Journal of the American Heart Association.