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DOI

  • Hannah G Caldwell
    The University of British Columbia
  • Geoff B Coombs
    The University of British Columbia
  • Hossein Rafiei
    The University of British Columbia
  • Philip N Ainslie
    The University of British Columbia
  • Jonathan P Little
    The University of British Columbia

Healthy males (n = 10; age: 24 ± 4 years; body mass index: 24 ± 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 ± 23% vs. -10 ± 28%; P = 0.015 and P = 0.253, respectively), vascular conductance (+32 ± 27% vs. -15 ± 26%; P = 0.012 and P = 0.098, respectively), and mean shear rate (+17 ± 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 ClinicalTrials.gov (NCT03374436). Novelty: Breaking up 8.5 h of sitting with hourly staircase sprinting exercise "snacks" improves resting femoral artery shear patterns but not FMD. Cerebral blood flow and neurovascular coupling were unaltered following 6 h of sitting with and without hourly exercise breaks.

Keywords

  • Adult, Carotid Artery, Internal/physiology, Cerebrovascular Circulation, Endothelium, Vascular/physiology, Femoral Artery/physiology, Hemodynamics, Humans, Leg/blood supply, Male, Pilot Projects, Pulmonary Gas Exchange, Sedentary Behavior, Stair Climbing/physiology, Time Factors, Vasodilation, Vertebral Artery/physiology, Young Adult
Original languageEnglish
Pages (from-to)521-529
Number of pages9
JournalApplied Physiology, Nutrition, and Metabolism
Volume46
Issue number5
DOIs
Publication statusPublished - May 2021
Externally publishedYes
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