Acute exercise has been shown to attenuate postprandial plasma triglyceride elevation (PPTG); however the direct contribution of exercise intensity is less well understood. The purpose of this study was to examine the effects of exercise intensity on PPTG and postprandial fat oxidation. Healthy, young men (n=6) performed one of three experimental treatments: non-exercise control (CON), moderate-intensity (MIE; 50% VO2 peak for 60 min), or isoenergetic high-intensity exercise (HIE; alternating 2 min at 25% and 2 min at 90% VO2 peak). The morning after the exercise, a standardized meal was provided (16 kcal/kg BM; 1.02 g fat/kg, 1.36 g CHO/kg, 0.31 g PRO/kg) and measurements of plasma concentrations of triglyceride (TG), glucose, insulin and β-hydroxybutyrate were made in the fasted condition and hourly for 6 h postprandial. Indirect calorimetry was used to determine fat oxidation in the fasted condition and 2, 4 and 6 h postprandial. Compared to CON, both MIE and HIE significantly attenuated PPTG (Incremental AUC) [75.2 (15.5) %, p = 0.033 and 54.9 (13.5) %, p = 0.001], with HIE also significantly lower than MIE (p = 0.03). Postprandial fat oxidation was significantly higher in MIE [83.3 (10.6) % of total energy expenditure) and HIE (89.1 (9.8) % of total] compared to CON [69.0 (16.1) % of total; p = 0.039 and; p = 0.018, respectively], with HIE significantly greater than MIE (p = 0.012). We conclude that, despite similar energy expenditure, HIE was more effective than MIE for lowering PPTG and increasing postprandial fat oxidation.
- postprandial plamsa triglycerides
- fat oxidation
- energy expenditure
- Copyright © 2012, Journal of Applied Physiology