Fasted exercise does not improve postprandial lipemia responses to different meals in adolescents: a randomized crossover clinical trial

Background: Prolonged postprandial hyperlipemia (PPL) and hyperglycemia (PPG) are im-portant risk factors for the development of cardiovascular disease. Although physical exercise improves lipid profile and glucose tolerance, thus reducing cardiovascular risk, the effects of fasting exercise in adolescents need to be investigated.Objective: We investigatedthe effects of different intensities of fasted aerobic exercise on the magnitude of PPL and glycemic responses to isocaloric meals in adolescents. Methods:A randomized crossover clinical trial in which 13 healthy and eutrophic adolescents, aged 14.5 ± 1.3 years, performed three interventions (wash-out period = 7 days): 45 minutes of rest (REST); 45 minutes of moderate-intensity fasting (MI); and a calorie-matched high-intensity aerobic exercise session (HI). Subjects were serially as-sessed for blood triglycerides, cholesterol, and glucose levels. Results: Regarding PPL, the MI protocol induced triglycerides reductions compared to REST only at 105 min (70.1 ± 10.3 vs 95.4 ± 30.2; p=0.006) and compared to both HI and REST at 135 min (68.4 ± 14.4 vs 91.5 ± 24.9 vs 93.7 ± 21.2 p<0.02). No differences in iAUC were observed. Conclusion: Calorie-matched moderate and high-intensity fasting aerobic exercise has no acute effect on PPL responsiveness in adolescents.