Did you know that even if you exercise regularly, you may be what researchers call an “active couch potato?” Consider this: If you exercise 30 to 45 minutes a day—completing your daily workout all at one time—it is easy to still spend 80 to 90 percent of your waking hours sitting. A study in England showed that while 55 percent or more of adults met recommended physical activity guidelines, they were still sedentary for about 10 hours per day.
Too many daily hours of inactivity, including time spent watching television—a classic couch potato move—may increase the risk of obesity and more than 30 other chronic illness. Inactivity has also been found to increase markers of heart disease. This activity imbalance can cancel out many of the positive effects of exercising, such as blood sugar control and better blood flow to the legs and brain. Being inactive for just four to six hours can cause an enzyme that helps the body use fat to make energy to drop.
Researchers from New Zealand compared people who sat for 18 hours without exercising (sedentary) with active couch potatoes who exercised for 30 minutes in between two nine-hour inactive stints. These groups were measured against a third group who exercised for just two minutes every half hour (light exercise). The sedentary and active couch potato groups had increased blood sugar levels. The light exercise group had better blood sugar control.
The results of these studies all seem to point to the same thing: No matter how active you are, it’s important to try to be less of a couch potato—or a more active, active couch potato. So, if your New Year’s resolution was to start a new exercise plan, don’t forget to also interrupt your sitting with a few minutes of walking throughout the day.
John Chatham, DPhil, is a professor of pathology in the Division of Molecular and Cellular Pathology at the University of Alabama at Birmingham.