Effect of repeated sprints on postprandial endothelial function and triacylglycerol concentrations in adolescent boys

This study investigated whether repeated, very short duration sprints influenced endothelial function (indicated by flow-mediated dilation) and triacylglycerol concentrations following the ingestion of high-fat meals in adolescent boys. Nine adolescent boys completed two, 2-day main trials (control and exercise), in a counter-balanced, cross-over design. Participants were inactive on day 1 of the control trial but completed 40x6s maximal cycle sprints on day 1 of the exercise trial. On day 2, capillary blood samples were collected and flow-mediated dilation measured prior to, and following, ingestion of a high-fat breakfast and lunch. Fasting flow-mediated dilation and plasma triacylglycerol concentration were similar in the control and exercise trial (P>0.05). In the control trial, flow-mediated dilation was reduced by 20% and 27% following the high-fat breakfast and lunch; following exercise these reductions were negated (main effect trial, P<0.05; interaction effect trialxtime, P<0.05). The total area under the plasma triacylglycerol concentration versus time curve was 13% lower on day 2 in the exercise trial compared to the control trial (8.65 (0.97) vs. 9.92 (1.16) mmol center dot l(-1)center dot 6.5h, P<0.05). These results demonstrate that repeated 6s maximal cycle sprints can have beneficial effects on postprandial endothelial function and triacylglycerol concentrations in adolescent boys.