If you are working long hours at the desk, do make it a point to take a five minute walk every hour to reverse negative effects of prolonged sitting, says an Indian-origin researcher. "We found that easy five minute walks can reverse harm caused to leg arteries during hours of prolonged sitting," claimed Saurabh Thosar, a post-doctoral researcher from the Oregon Health and Science University. When people sit, slack muscles do not contract to effectively pump blood to the heart. Blood can pool in the legs and affect the endothelial function of arteries or the ability of blood vessels to expand from increased blood flow. "We have shown that prolonged sitting impairs endothelial function, which is an early marker of cardio-vascular disease and that breaking sitting time prevents the decline in that function," added Thosar, who led the study as a doctoral candidate from Indiana University's school of public health. The study involved 11 non-obese, healthy men between ages 20-35. In one trial, they sat for three hours without moving their legs. In the second trial, the men sat during a three-hour period but also walked on a treadmill for five minutes at a speed of two mph at the half hour, 1.5 and 2.5 hour marks respectively. Researchers demonstrated that during a three-hour period, the flow mediated dilation, or the expansion of the arteries as a result of increased blood flow, of the main artery in the legs was impaired by as much as 50 percent after just one hour. The participants who walked for five minutes each hour of sitting saw their arterial function stay the same - it did not drop throughout the three-hour period. "Normally, a working adult sits for approximately eight hours a day. The impairment in endothelial function is significant after just one hour of sitting. It is interesting to see that light physical activity can help in preventing this impairment," Thosar concluded.
