Exercise intensity and the protection from postprandial vascular dysfunction in adolescents
American Journal of Physiology - Heart and Circulatory Physiology
American Physiological Society
© 2015 the American Physiological Society
BACKGROUND: Acute exercise transiently improves endothelial function, and protects the vasculature from the deleterious effects of a high fat meal (HFM). We sought to identify whether this response is dependent on exercise intensity in adolescents. METHODS: Twenty adolescents (10 male, 14.3 ± 0.3 y) completed three 1-day trials: 1) rest (CON); 2) 8x1 min cycling at 90% peak power with 75s recovery (high-intensity interval exercise; HIIE); 3) cycling at 90% of the gas exchange threshold (moderate-intensity exercise; MIE) one hour before consuming a HFM (1.50 g∙kg(-1) fat). Macrovascular and microvascular endothelial function were assessed before and immediately after exercise, and three hours after the HFM by flow mediated dilation (FMD) and laser Doppler imaging (peak reactive hyperaemia; PRH). RESULTS: FMD and PRH increased one hour after HIIE (P<0.001, ES=1.20 and P=0.048, ES=0.56) but were unchanged after MIE. FMD and PRH were attenuated three hours after the HFM in CON (P<0.001, ES=1.78 and P=0.02, ES=0.59). FMD remained greater three hours after the HFM in HIIE compared to MIE (P<0.001, ES=1.47) and CON (P<0.001, ES=2.54), and in MIE compared to CON (P<0.001, ES=1.40). Compared to CON, PRH was greater three hours after the HFM in HIIE (P=0.02, ES=0.71) and MIE (P=0.02, ES=0.84), with no differences between HIIE and MIE (P=0.72, ES=0.16). Plasma [triacylglycerol] and [total antioxidant status] were not different between trials. CONCLUSIONS: Exercise intensity plays an important role in protecting the vasculature from the deleterious effects of a HFM. Performing HIIE may provide superior vascular benefits than MIE in adolescent groups.
This is the author accepted manuscript. The final version is available from American Physiological Society via the DOI in this record
Vol. 308 (11), pp. H1443-H1450