TY - JOUR

T1 - Hourly staircase sprinting exercise “snacks” improve femoral artery shear patterns but not flow-mediated dilation or cerebrovascular regulation

T2 - A pilot study

AU - Caldwell, Hannah Grace

AU - Coombs, Geoff B

AU - Rafiei, Hossein

AU - Ainslie, Philip N

AU - Little, Jonathan P

N1 - Publisher Copyright: © 2021, Canadian Science Publishing. All rights reserved.

PY - 2021

Y1 - 2021

N2 - Healthy males (n = 10; age: 24 ± 4 years; bodymass index: 24 6 2 kg·m-2) completed 2 randomized conditions separated by ≥48 h involving 6-8.5 h of sitting with (“stair snacks”) and without (sedentary) hourly staircase sprint interval exercise (~14-20 s each). Resting blood flow and shear rates were measured in the femoral artery, internal carotid artery, and vertebral artery (Duplex ultrasound). Flow-mediated dilation (FMD) was quantified as an index of peripheral endothelial function in the femoral artery. Neurovascular coupling (NVC; regional blood flow response to local increases in cerebral metabolism) was assessed in the posterior cerebral artery (transcranial Doppler ultrasound). Femoral artery hemodynamics were higher following the active trial with no change in the sedentary trial, including blood flow (+32 6 23% vs. -10 ± 28%; P = 0.015 and P = 0.253, respectively), vascular conductance (+32 ± 27% vs. _15 6 26%; P = 0.012 and P = 0.098, respectively), and mean shear rate (+17 6 8% vs. -8 ± 28%; P = 0.004 and P = 0.310, respectively). The change in FMD was not different within or between conditions (P = 0.184). Global cerebral blood flow (CBF), conductance, shear patterns, and NVC were not different within or between conditions (all P > 0.05). Overall, exercise “stair snacks” improve femoral artery blood flow and shear patterns but not peripheral (e.g., FMD) or cerebral (e.g., CBF and NVC) vascular function following prolonged sitting. The study was registered at Clinical- Trials.gov (NCT03374436).

AB - Healthy males (n = 10; age: 24 ± 4 years; bodymass index: 24 6 2 kg·m-2) completed 2 randomized conditions separated by ≥48 h involving 6-8.5 h of sitting with (“stair snacks”) and without (sedentary) hourly staircase sprint interval exercise (~14-20 s each). Resting blood flow and shear rates were measured in the femoral artery, internal carotid artery, and vertebral artery (Duplex ultrasound). Flow-mediated dilation (FMD) was quantified as an index of peripheral endothelial function in the femoral artery. Neurovascular coupling (NVC; regional blood flow response to local increases in cerebral metabolism) was assessed in the posterior cerebral artery (transcranial Doppler ultrasound). Femoral artery hemodynamics were higher following the active trial with no change in the sedentary trial, including blood flow (+32 6 23% vs. -10 ± 28%; P = 0.015 and P = 0.253, respectively), vascular conductance (+32 ± 27% vs. _15 6 26%; P = 0.012 and P = 0.098, respectively), and mean shear rate (+17 6 8% vs. -8 ± 28%; P = 0.004 and P = 0.310, respectively). The change in FMD was not different within or between conditions (P = 0.184). Global cerebral blood flow (CBF), conductance, shear patterns, and NVC were not different within or between conditions (all P > 0.05). Overall, exercise “stair snacks” improve femoral artery blood flow and shear patterns but not peripheral (e.g., FMD) or cerebral (e.g., CBF and NVC) vascular function following prolonged sitting. The study was registered at Clinical- Trials.gov (NCT03374436).

KW - Cerebral blood flow

KW - Duplex ultrasound

KW - Exercise breaks

KW - Flow-mediated dilation

KW - Prolonged sitting

KW - Vascular function

UR - http://www.scopus.com/inward/record.url?scp=85106008712&partnerID=8YFLogxK

U2 - 10.1139/apnm-2020-0562

DO - 10.1139/apnm-2020-0562

M3 - Journal article

C2 - 33242251

AN - SCOPUS:85106008712

VL - 46

SP - 521

EP - 529

JO - Applied Physiology, Nutrition and Metabolism

JF - Applied Physiology, Nutrition and Metabolism

SN - 1715-5312

IS - 5

ER -