Hourly staircase sprinting exercise snacks improved resting femoral artery shear patterns but did not significantly alter flow-mediated dilation or cerebrovascular regulation compared to prolonged sitting.
RCT (n=10)
Randomized crossover
No
Does breaking up prolonged sitting with hourly staircase sprinting exercise 'snacks' improve peripheral and cerebral vascular function in healthy young males?
Hourly brief stair-climbing 'snacks' can acutely improve leg vascular shear patterns during prolonged sitting, though they do not acutely alter flow-mediated dilation or cerebral hemodynamics.
Absolute Event Rate: -1.53% vs 1.57%
p-value: p=0.184
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.
Caldwell et al. (Thu,) conducted a rct in Prolonged sitting (n=10). Hourly staircase sprinting exercise "snacks" vs. Uninterrupted sitting (sedentary) was evaluated on Change in flow-mediated dilation (FMD) (p=0.184). Hourly staircase sprinting exercise snacks improved resting femoral artery shear patterns but did not significantly alter flow-mediated dilation or cerebrovascular regulation compared to prolonged sitting.