Haoxuan Liu1, Myles W O'Brien1, Jarrett A Johns1, Derek S Kimmerly2. 1. Autonomic Cardiovascular Control and Exercise Laboratory, Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, 6230 South Street, Halifax, NS, B3H 4R2, Canada. 2. Autonomic Cardiovascular Control and Exercise Laboratory, Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, 6230 South Street, Halifax, NS, B3H 4R2, Canada. dskimmerly@dal.ca.
Abstract
PURPOSE: Acute prolonged bouts of sitting reduce popliteal artery blood flow and flow-mediated dilation (FMD). Individuals with higher aerobic fitness have enhanced popliteal FMD. Conflicting evidence regarding whether more aerobically fit individuals are protected from the negative impacts of sitting on popliteal endothelial function in male-dominated studies have been reported. We further explored the relationship between aerobic fitness and sitting-induced impairments in popliteal blood flow and FMD in a more sex-balanced cohort. METHODS: Relative peak oxygen consumption (V̇O2peak) was assessed using a cycling-based incremental test in 21 healthy adults (eight males; 23 ± 2 years; 23.9 ± 2.9 kg/m2). Popliteal blood flow and relative FMD (%) were measured via duplex ultrasonography before and after 3 h of uninterrupted sitting. Pearson correlations were performed separately between V̇O2peak versus pre-sitting and sitting-induced reductions in popliteal outcomes. RESULTS: Aerobic fitness (41.0 ± 9.7 ml/kg/min) was positively correlated with pre-sitting popliteal blood flow (65 ± 23 mL/min; R = 0.59, P = 0.005) and relative FMD (4.2 ± 1.5%; R = 0.49, P = 0.03). As expected, sitting reduced resting blood flow (19 ± 11 mL/min) and FMD (1.9 ± 0.7%) (both, P < 0.001). V̇O2peak was inversely related to sitting-induced declines in blood flow (Δ-46 ± 23 mL/min; R = - 0.71, P < 0.001) and FMD (Δ-2.4 ± 1.5%; R = - 0.51, P = 0.02). CONCLUSIONS: Although higher aerobic fitness was associated with more favorable popliteal endothelial-dependent vasodilator responses, it also corresponded with larger sitting-induced impairments in FMD. This suggests that being more aerobically fit does not protect against sitting-induced vascular endothelial dysfunction. As such, all young adults should minimize habitual prolonged sedentary bouts, regardless of their aerobic fitness level.
PURPOSE: Acute prolonged bouts of sitting reduce popliteal artery blood flow and flow-mediated dilation (FMD). Individuals with higher aerobic fitness have enhanced popliteal FMD. Conflicting evidence regarding whether more aerobically fit individuals are protected from the negative impacts of sitting on popliteal endothelial function in male-dominated studies have been reported. We further explored the relationship between aerobic fitness and sitting-induced impairments in popliteal blood flow and FMD in a more sex-balanced cohort. METHODS: Relative peak oxygen consumption (V̇O2peak) was assessed using a cycling-based incremental test in 21 healthy adults (eight males; 23 ± 2 years; 23.9 ± 2.9 kg/m2). Popliteal blood flow and relative FMD (%) were measured via duplex ultrasonography before and after 3 h of uninterrupted sitting. Pearson correlations were performed separately between V̇O2peak versus pre-sitting and sitting-induced reductions in popliteal outcomes. RESULTS: Aerobic fitness (41.0 ± 9.7 ml/kg/min) was positively correlated with pre-sitting popliteal blood flow (65 ± 23 mL/min; R = 0.59, P = 0.005) and relative FMD (4.2 ± 1.5%; R = 0.49, P = 0.03). As expected, sitting reduced resting blood flow (19 ± 11 mL/min) and FMD (1.9 ± 0.7%) (both, P < 0.001). V̇O2peak was inversely related to sitting-induced declines in blood flow (Δ-46 ± 23 mL/min; R = - 0.71, P < 0.001) and FMD (Δ-2.4 ± 1.5%; R = - 0.51, P = 0.02). CONCLUSIONS: Although higher aerobic fitness was associated with more favorable popliteal endothelial-dependent vasodilator responses, it also corresponded with larger sitting-induced impairments in FMD. This suggests that being more aerobically fit does not protect against sitting-induced vascular endothelial dysfunction. As such, all young adults should minimize habitual prolonged sedentary bouts, regardless of their aerobic fitness level.
Authors: Nicolas Aguilar-Farias; Pía Martino-Fuentealba; Nicolas Salom-Diaz; Wendy J Brown Journal: J Sci Med Sport Date: 2018-12-14 Impact factor: 4.319
Authors: Ryan S Garten; Austin C Hogwood; Jennifer B Weggen; R Carson Fralin; Kathryn LaRosa; David Lee; Austin Michael; Matthew Scott Journal: Appl Physiol Nutr Metab Date: 2018-09-26 Impact factor: 2.665
Authors: Tom G Bailey; Maria Perissiou; Mark Windsor; Fraser Russell; Jonathan Golledge; Daniel J Green; Christopher D Askew Journal: J Appl Physiol (1985) Date: 2017-02-16
Authors: Ryan M Broxterman; Joel D Trinity; Jayson R Gifford; Oh Sung Kwon; Andrew C Kithas; Jay R Hydren; Ashley D Nelson; David E Morgan; Jacob E Jessop; Amber D Bledsoe; Russell S Richardson Journal: J Appl Physiol (1985) Date: 2017-08-31
Authors: Kevin P Decker; Patrick G Feliciano; Morgan T Kimmel; Austin C Hogwood; Jennifer B Weggen; Ashley M Darling; Jacob W Richardson; Ryan S Garten Journal: Microvasc Res Date: 2021-02-19 Impact factor: 3.514