Exercise May Not Be Enough to Cancel Out Sedentary Behavior, New Research Finds
You might want to sit down for this: a new study found that exercising may not be enough to balance out the harmful effects of prolonged sitting. The report, published in The American Journal of Physiology—Endocrinology and Metabolism, is off an experiment that observed physiological interactions between inactivity and exercise.
Researchers from the University of Texas at Austin monitored seven volunteers over eight days—four active (walking at least 17,000 steps) and four sedentary (sitting for 14 hours at a time)—with periodic workouts followed by a high-fat breakfast. After four active days, that workout was enough to reduce triglycerides (fat) in the subjects’ blood, but after the four sedentary days, it wasn’t.
The findings disproves the idea that people can be “active couch potatoes” who successfully counteract long bouts of sitting with occasional vigorous workouts. But how does that work, though? What does sitting do to our bodies that can’t be undone by a trip to the gym?
The answer is still a bit muddy. University of Texas kinesiology professor Edward F. Coyle, who helped supervise the experiment, says that those four sedentary days “made the men’s bodies exercise-resistant,” explaining that sitting around so much made subsequent exercise less effective. What’s happening on the cellular level isn’t evident yet, though.
Coyle concedes that more experiments are needed to determine exactly how our physiology changes during long stretches of inactivity. Further, a more diverse range of subjects will be needed for that kind of analysis; all the subjects in this study were young, healthy and male.