Not all sedentary behavior is equal, say researchers from Universidad Autónoma de Madrid in Spain, who evaluated the sedentary habits of 5,459 women and 4,740 men.
The researchers note that several studies have found that, unlike, for example, computer use and reading, TV watching is consistently associated with adverse health outcomes, such as metabolic syndrome, obesity, and diabetes mellitus (DM). But different sedentary behaviors (SBs) have different health effects, they add. They cite research that suggests TV and other “passive” SBs (eg, listening or talking while sitting) could be more harmful than “mentally active” SBs, such as computer use and reading. In this study, “passive” sedentary time, such as TV watching, was associated with less recreational activity and higher body weight. Time at the computer and reading were linked to more recreational physical activity but less light-intensity activity at home.
Moreover, each type of SB has a distinct demographic and lifestyle profile, the researchers say. Older age, lower education, unhealthy lifestyle (smoking, worse diet, less physical activity, higher BMI) and chronic morbidity, such as DM or osteomuscular disease, were linked to more TV time. Longer time at the computer or in commuting was linked to younger age, male gender, higher education, and a sedentary job.
Watching TV had no association with total time spent on the rest of leisure-time SBs. The researchers also found that “mentally active” SBs, such as using the computer and reading, tend to cluster.
Many studies have looked at the effects of and connections between SB, lifestyle choices, and health. The researchers of this study say theirs extends knowledge in the field by considering more types of SB (using the computer, commuting, lying in the sun, listening to music, and reading). To their knowledge, they say, no previous study on a representative sample of an entire country has examined the association between TV watching time and the rest of SB, or has reported the full profile of sociodemographic, lifestyle, and health variables associated with each type of SB.
Watching TV was the predominant SB (45% of total sitting time), followed by sitting at the computer (23%), reading (15%), and commuting (12%). The participants spent a mean of 1.96 hours a day watching TV, vs > 1 hour for the other behaviors.