The Influence of a Single Bout of High-Intensity Interval Exercise on Postprandial Lipemia and Glycemia

PURPOSE: Examine the effects of high-intensity interval exercise (HIIE) on postprandial (PP) triglyceride (TG), glucose, and insulin concentrations following a mixed meal (MM). METHODS: Physically active men (n=10; age=22.2±2.1yrs; body mass = 82.7±13.2kg; body fat% = 13.3±3.1) completed two trials in random order: 1) Rest and 2) A single bout of high-intensity interval exercise (HIIE). Both trials were performed at 0800 hours. HIIE consisted of performing eight (15-second) maximal effort sprints on a stationary bicycle. Each sprint was followed with approximately 3 minutes of passive cycling with no resistance. Rest consisted of sitting quietly for 30 minutes. Approximately 30 minutes following the completion of each trial, a fasting (12hr) blood sample was collected followed by the consumption of the MM providing 7.5±1.2 kcal/kgBM (body mass) with a macronutrient composition of 35% carbohydrate (CHO), 5% protein, and 60% fat. The MM was blended with whole milk, ice cream, and whipping cream. Blood was collected again at 0.5, 1, 2, and 3 hours post-MM and analyzed for TG, insulin, and glucose concentration. Postprandial responses were quantified via the incremental area under the curve (AUCI) using the trapezoidal method. Significant differences (p<.05) between trials were determined using a one-way, repeated measures ANOVA and Bonferroni post hoc test. RESULTS: The duration of the HIIE was 24 minutes (not including a 5-minute warm up). HIIE expended 90.1±11.8 kcal. HIIE significantly reduced the glucose AUCI (Rest: 9.9±43.1mg·dl-1·3hr-1; HIIE: -39.9±37.0mg·dl-1·3hr-1; p=.010) and insulin AUCI (Rest: 36.2±25.4μIU·ml-1·3hr-1; HIIE: 5.9±30.7μIU·ml-1·3hr-1; p=.035) with no significant effect on TG AUCI (Rest: 57.2±52.8mg·dl-1·3hr-1; HIIE: 78.7±46.5mg·dl-1·3hr-1; p=.20). CONCLUSION: HIIE blunted the postprandial glucose and insulin response to high-fat mixed meal in young physically active men. The lack of change in the TG concentration might be explained by the lower energy expenditure of the HIIE due to its short duration. Future investigations should evaluate the applicability of HIIE within an at-risk populations (i.e. obesity, diabetes). This study was supported by the Stephen F. Austin State University Research Pilot Study Grant and the Texas ACSM Student Research Development Grant.