Darden College of Education & Professional Studies


M.S. Exercise Science

Publication Date



Previous studies demonstrate prolonged sitting impairs blood vessel function. However, these studies also demonstrate breaking up sitting time by exercise maintains endothelial function. No one has examined whether a continuous bout of exercise prior to sitting is as effective as breaks in sitting on maintaining endothelial function. PURPOSE: This study examined whether continuous versus intermittent bouts of exercise are more effective at maintaining vascular health while sitting. METHODS: 5 males (age: 36±18, BMI: 22±5) and 1 female participated in three randomized 3-hour sitting trials where popliteal endothelial function was measured via Doppler ultrasound every hour. In the sedentary trial (SED), subjects sat for 3 continuous hours with their leg in a 90° bend. In the continuous exercise trial (CON), the subjects walked for 30-minutes at 2-mph on a treadmill before sitting for 3-hours. During the intermittent exercise trial (INT), subjects sat for 3 hours similar to the SED condition; however, every 30-minutes they walked at 2-mph for 5-minutes. Flow-mediated dilation (FMD) was performed at baseline, 1-hr, 2-hr, and 3-hr in each trial. RESULTS: Percent change in FMD was unaltered between groups or across each trial (p>0.05). CONCLUSIONS: These preliminary data suggest that endothelial function is unaltered across the groups. This is an ongoing study and we are actively recruiting more individuals to increase the power of this study due to our low sample size.



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The Impact of Continuous Versus Intermittent Physical Activity on Vascular Function While Sitting



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