Preexercise Intermittent Passive Stretching and Vascular Function After Treadmill Exercise.

Abstract

Acute aerobic exercise stress is associated with decreased endothelial function that may increase the likelihood of an acute cardiovascular event. Passive stretch (PS) elicits improvements in vascular function, but whether PS can be performed before exercise to prevent declines in vascular function remains unknown. This strategy could be directly applicable in populations that may not be able to perform dynamic exercise. We hypothesized that preexercise PS would provide better vascular resilience after treadmill exercise. Sixteen healthy college-aged males and females participated in a single laboratory visit and underwent testing to assess micro- and- macrovascular function. Participants were randomized into either PS or sham-control. Intermittent calf PS was performed by having the foot in a splinting device for a 5-minute stretch, 5-minute relaxation, repeated 4 times. Then, a staged O2 peak test was performed and 65% O2 peak calculated for subjects to run at for 30-minutes. Near-infrared spectroscopy derived microvascular responsiveness was preserved with the PS group (pre: 0.53±0.009%/s), (post: 0.56±0.012%/s; p=0.55). However, there was a significant reduction in the sham control group (pre: 0.67±0.010%/s), (post: 0.51±0.007%/s; p=0.05) after treadmill exercise. Flow mediated vasodilation (FMD) of the popliteal artery showed similar responses. In the PS group, FMD (pre: 7.23±0.74%), (post: 5.86±1.01%; p=0.27) did not significantly decline after exercise. In the sham-control group FMD (pre: 8.69±0.72), (post: 5.24±1.24%; p<0.001) was significantly reduced after treadmill exercise. Vascular function may be more resilient if intermittent PS is performed prior to moderate intensity exercise and, importantly, can be performed by most individuals.