University Study Demonstrates Significant Blood Flow Impairment from Prolonged Sitting

As more and more research surfaces revealing the negative health effects of sitting, people are attempting to find ways to combat those adverse health effects. Recently, an Indiana University study has found that walking for five minutes every hour can reverse harm caused to leg arteries during an hour of prolonged sitting.


The reasoning behind this claim is that when you sit, slack muscles do not contract to effectively pump blood to the heart. Hence, 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. This university study is the first experimental evidence of these effects.


During this study, researchers were able to demonstrate that 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. However, the participants who walked for five minutes after every hour of sitting saw no change in their arterial function.


The study involved 11 non-obese, healthy men with ages ranging from 20 to 35 who participated in two randomized trials. In one trial they sat for three hours without moving their legs. In the other trial they sat for a three-hour period but also walked on a treadmill for five minutes at the speed of 2 mph halfway through each hour. Researchers used a blood pressure cuff and ultrasound technology to measure the functionality of the femoral artery at baseline and again at each hour mark.


The study, “Effect of Prolonged Sitting and Breaks in Sitting Time on Endothelial Function,” will be published in the spring in Medicine & Science in Sports & Exercise, the official journal of the American College of Sports Medicine.


American adults sit for about eight hours a day. The health effects are visible after just one hour. Knowing this, everyone should take action to disrupt prolonged sitting every hour, whether it’s working at a stand up desk or taking a break to walk for five minutes through the office.

Reid Hollen
Reid Hollen