IF you've been reading this column for a while, you may know by now that sitting is bad for you. It turns out that sitting may actually reverse the effects of exercise. A study in the Journal of Applied Physiology suggests that by sitting, our bodies are altered in an unhealthy way, decreasing the health effects of exercise.
We know that exercise improves one’s chances against heart disease, diabetes risk and the like, and that a sedentary lifestyle increases the risk for these lifestyle diseases. What is puzzling though, is how these physiological effects happen.
Researchers from the University of Texas asked a group of 10 physically active students to sit in couches and remain there, not moving for several days. The goal was to learn about the effects of inactivity and exercise on the subject’s metabolisms, and if whether one would dominate over the other.
Volunteers were asked to stop moving and take fewer than 4,000 steps a day or stay 13 hours sedentary. The volunteers followed through with the instructions, sitting uninterrupted four days in a row. On the fifth day, volunteers were given a large breakfast composed of ice cream. The idea was to study how the subjects’ metabolism responded to this extremely fatty and sugary meal after being idle. Their blood was measured for triglycerides, blood sugar and insulin for the next six hours. The experiment was repeated again, asking the subjects once more to be completely still. Then, the subjects were asked to exercise, running briskly for hours.
The results of the study showed that after four days of zero exercise, the subjects were sluggish with overtaxed metabolisms. Hours after their breakfast, they had high levels of triglycerides, blood sugar and low insulin sensitivity. What surprised the researchers most is that even the exercise protocol did not help.
What does this mean to all of us? This study shows that a prolonged sedentary lifestyle may blunt the effects of acute exercise, at least in the short run. This current news only reinforces the fact that we should move more often, sit less and keep an active lifestyle.