Resistance exercise breaks during prolonged sitting augment the blood flow response to a subsequent oral glucose load...

Sitting-induced impairments in postprandial blood flow are an important link between sedentary behaviour and cardiometabolic disease risk. The objective of this work was to examine the effects of resistance exercise breaks (REB) performed every 30 min during an otherwise sedentary 3-h period on the vasodilatory response to a subsequent oral glucose load in sedentary adults. Twenty-four sedentary adults (27 ± 7 years, 16 females) completed two conditions. Fasting blood glucose, insulin, popliteal artery blood flow (PABF) and gastrocnemius perfusion were measured immediately before standardized breakfast consumption. After breakfast, the 3-h REB or uninterrupted (SIT) intervention period commenced. Participants sat at a workstation, and popliteal artery shear rate (PASR) was measured 60 and 120 min into this period. In the REB condition, participants performed a 3-min REB (3 × [20 s squats, 20 s high knees, 20 s calf raises]) every 30 min. Following the intervention period, baseline measurements were repeated. Participants then consumed a 75 g glucose beverage, and PABF and perfusion were measured every 30-60 min for the following 120 min. Relative to SIT, REB increased PASR at 60 min (+31.4 ± 9.2/s, P = 0.037) and 120 min (+37.4 ± 10.2/s, P = 0.019) into the intervention period. Insulin and glucose increased (P < 0.001) in response to glucose consumption, with no differences between conditions (P ≥ 0.299). In response to the glucose load, perfusion (1.57 vs. 1.11 mL/100 mL/min, P = 0.023) and PABF (+45.3 ± 11.8 mL/min, P = 0.001) were greater after REB versus SIT. Performing 3-min REB every 30 min during an otherwise sedentary 3-h period augmented leg blood flow responses to an oral glucose load.