Short Walks Reverse Negative Effects of Prolonged Sitting, Study

A latest study shows that short walks help reverse the negative effects of prolonged sitting on leg arteries.

Studies conducted earlier showed that people whose occupations demand sitting for a prolonged period of time, face a higher risk of greater waist circumference and elevated levels of cholesterol that further lead to cardiovascular and metabolic diseases.

Due to sitting for long periods, the slack muscles fail to contract to effectively pump blood to the heart. Blood pools in the legs and affect the endothelial function of the arteries or the ability of the blood vessels to expand from rise in flow of blood. This is one of the early studies that highlights these effects.

"There is plenty of epidemiological evidence linking sitting time to various chronic diseases and linking breaking sitting time to beneficial cardiovascular effects, but there is very little experimental evidenceWe have shown that prolonged sitting impairs endothelial function, which is an early marker of cardiovascular disease, and that breaking sitting time prevents the decline in that function," said Saurabh Thosar, a postdoctoral researcher at the Oregon Health & Science University, who led the study as a doctoral candidate at IU's School of Public Health-Bloomington.

The study was conducted on 11 non-obese healthy men aged between 20-35 years. They were made to participate in two randomized trials. In the first trail, the participants were made to sit for three hours without moving their legs. The blood pressure cuff and ultrasound technology was used to measure the functionality of the femoral artery at baseline and at one, two and three hour mark.

In the second trial, the men sat during the three-hour period, but also walked on treadmill for 5 minutes at the speed of 2mph at 30 minute mark, 1.5 hour mark and 2.4 hour mark. At the same interval the researchers measured the function of the femoral artery.

The researchers noticed that during the three-hour period, the flow-mediated dilation, or the expansion of the arteries due to increased blood flow, of the main artery in the leg was impaired by 50 percent after an hour of walk.  Those participants who walked for 5 minutes each hour noticed no difference in the arterial function. This may be due to the rise in muscle activity and blood flow.

"American adults sit for approximately eight hours a day," Thosar said. "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."

  The finding was published in the Medicine & Science in Sports & Exercise.