title: Prior exercise and standing as strategies to circumvent sitting-induced leg endothelial dysfunction.
abstract: We have previously shown that local heating or leg fidgeting can prevent prolonged sitting-induced leg endothelial dysfunction. However, whether physical activity prevents subsequent sitting-induced leg endothelial dysfunction remains unknown. Herein, we tested the hypothesis that sitting-induced leg endothelial dysfunction would be prevented by prior exercise. We also examined if, in the absence of exercise, standing is an effective alternative strategy to sitting for conserving leg endothelial function. Fifteen young healthy subjects completed three randomized experimental trials: (1) sitting without prior exercise; (2) sitting with prior exercise; and (3) standing without prior exercise. Following baseline popliteal artery flow-mediated dilation (FMD) measurements, subjects maintained a supine position for 45 min in the sitting and standing trials, without prior exercise, or performed 45 min of leg cycling before sitting (i.e. sitting with prior exercise trial). Thereafter, subjects were positioned into a seated or standing position, according to the trial, for 3 h. Popliteal artery FMD measures were then repeated. Three hours of sitting without prior exercise caused a significant impairment in popliteal artery FMD (baseline: 3.8±0.5%, post-sitting: 1.5±0.5%,P<0.05), which was prevented when sitting was preceded by a bout of cycling exercise (baseline: 3.8±0.5%, post-sitting: 3.6±0.7%,P>0.05). Three hours of standing did not significantly alter popliteal artery FMD (baseline: 4.1±0.4%, post-standing: 4.3±0.4%,P>0.05). In conclusion, prolonged sitting-induced leg endothelial dysfunction can be prevented by prior aerobic exercise. In addition, in the absence of exercise, standing represents an effective substitute to sitting for preserving leg conduit artery endothelial function.
authors.affiliation: Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, U.S.A.|Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.|Japan Society for the Promotion of Science, Chiyoda, Tokyo, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Morishima
authors.affiliation: Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, U.S.A.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Restaino
authors.affiliation: Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, U.S.A.
authors.forename: Lauren K
authors.initials: LK
authors.lastname: Walsh
authors.affiliation: Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, U.S.A.
authors.forename: Jill A
authors.initials: JA
authors.lastname: Kanaley
authors.affiliation: Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, U.S.A. padillaja@missouri.edu.|Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, U.S.A.|Child Health, University of Missouri, Columbia, MO, U.S.A.
authors.forename: Jaume
authors.initials: J
authors.lastname: Padilla
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology; D004730:Endothelium, Vascular / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D011150:Popliteal Artery / Q000502:physiology; D011187:Posture / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D013314:Stress, Mechanical
keywords: aerobic exercise; blood flow; endothelial function; shear stress; sitting