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

Abstract

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 30min 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 120min into this period. In the REB condition, participants performed a 3-min REB (3 × [20s squats, 20s high knees, 20s calf raises]) every 30min. Following the intervention period, baseline measurements were repeated. Participants then consumed a 75g glucose beverage, and PABF and perfusion were measured every 30-60min for the following 120min. Relative to SIT, REB increased PASR at 60min (+31.4±9.2/s, P=0.037) and 120min (+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 (1.57vs. 1.11mL/100mL/min, P=0.023) and PABF (+45.3±11.8mL/min, P=0.001) were greater after REB versus SIT. Performing 3-min REB every 30min during an otherwise sedentary 3-h period augmented leg blood flow responses to an oral glucose load. HIGHLIGHTS: What is the central question of this study? Can 3-min resistance exercise breaks (REB) performed during an otherwise sedentary 3-h period augment the vasodilatory response to a subsequent oral glucose load in sedentary adults? What is the main finding and its importance? Performing 3-min REB, which included squats, high knees, and calf raises, every 30min augmented lower limb blood flow responses to a subsequent oral glucose load compared to 3h of uninterrupted sitting in sedentary adults. Sitting-induced impairment in postprandial vasodilatory function has been identified as a link between sedentary behaviour and cardiometabolic disease. Thus, the current study presents a potentially effective strategy to offset this risk.