Acute moderate-intensity exercise reduces postprandial lipemia in boys. However, the effect of high-intensity exercise has not been investigated. This study examined the effect of low-volume, high-intensity interval running (HIIR) on postprandial plasma triacylglycerol (TAG) concentrations.Methods
Fifteen healthy, active boys (means ± SD; age = 11.8 ± 0.4 yr, body mass = 42.8 ± 8.0 kg, peak oxygen uptake [V˙O2] = 55 ± 6 mL·kg−1·min−1) completed two 2-d trials in a counterbalanced, crossover design separated by 14 d. On day 1, participants rested (CON) or completed 10 × 1 min running intervals at 100% maximal aerobic speed, determined from an incremental peak V˙O2 test, with 1 min recovery between intervals (HIIR). On day 2, capillary blood samples were taken in the fasted state and at predetermined intervals throughout the 6.5-h postprandial period while participants rested. A standardized breakfast was consumed at 0800 h, immediately after the fasting sample, and a standardized lunch meal was consumed at 1200 h.Results
Differences in fasting plasma TAG concentration were small to moderate (95% confidence interval [CI] = −0.11 to 0.01, effect size [ES] = 0.40). Postprandial TAG concentration was lower during HIIR compared with CON (95% CI = −0.19 to −0.02, ES = 0.58). The total area under the TAG concentration versus time curve was lower after HIIR compared with CON (5.2 ± 1.1 vs 5.8 ± 1.5 mmol·L−1 6.5 h; 95% CI = −1.18 to −0.12, ES = 0.50).Conclusion
This is the first study to show that low-volume HIIR attenuates postprandial TAG concentration in healthy, active 11- to 12-yr-old boys.