We should have guessed that an activity as fun as watching television would eventually be found to be bad for us! A recent study out of Australia shows the health risk of watching TV. The study from the physical activity lab at the Baker IDI Heart and Diabetes Institute in Victoria, Australia found that the more television its subjects watched, the greater risk they had of dying at a younger age, particularly from heart disease.
Subjects in the study who watched four hours or more of television per day were 80% more likely to die from heart disease and 46% more likely to die from all causes, even when factors such as education levels, overall health, age, past smoking, waist circumference, cholesterol levels, and blood pressure of the subjects was taken into account.
The study concluded that the real problem with television watching is that it is done while sitting, and sitting with extraordinarily little muscle movement. Such “extreme” inactivity affects metabolism overall, not just during the time spent inactive. A study from July 2008 showed that standing engages muscles and promotes the distribution of lipase, a fat-absorbing enzyme that triggers the body to process fat and cholesterol. Most important, the benefits of this regular, unremarkable movement are independent from the amount of time subjects spent exercising.
That same study found that the health consequences that develop from too much sitting are very different and independent from those that result from too little exercise. Along with the recent Australian study, it found that the negative health consequences of prolonged periods of sitting — larger waistlines, higher bad cholesterol levels, lower good cholesterol levels, heart disease risks — were not fully counteracted by regular exercise.
Harvard Health Publications estimates that, when it comes to calories burned, watching television (56 calories per hour) is closer to sleeping (46 calories per hour) than it is to sitting and reading (84 calories per hour), which itself is more akin to standing in line (94 calories per hour) than it is to watching television. In other words, watching television is an inactive as a person can get without sleeping.