Acute endurance exercise has been shown to lower postprandial plasma triglyceride concentrations (PPTG); however whether this is due to the negative energy and/or carbohydrate deficit from the exercise bout is not well understood.
Purpose: To examine the effects of a post-exercise meal consisting of either high or low carbohydrate content on PPTG and postprandial fat oxidation the morning after an exercise bout.
Methods: Healthy, young men (n=6) performed each of four experimental treatments: 1) non-exercise control (CON), 2) 80 min of cycling with either no meal replacement (EX), 3) a high carbohydrate post-exercise meal (EX+HCHO), or a 4) low carbohydrate post-exercise meal (EX+LCHO). A standardized meal for PPTG determination was provided (16.0 kcal/kg BM; 1.02 g fat/kg, 1.36 g CHO/kg, 0.31 g Pro/kg) 12h after the exercise and measures of plasma triglyceride concentration (TG) and whole body resting fat oxidation were made in the fasted condition and during the 4h postprandial period.
Results: The total area under the curve for plasma triglyceride (TG AUC) was significantly lower in EX+LCHO [325 (63) mg/dL/4h] compared to EX+HCHO [449 (118) mg/dL/4h; p=0.03]. Postprandial fat oxidation during this period was significantly greater in EX+LCHO [257 (58) kcal/4h; p=0.003] compared to EX+HCHO [209 (56) kcal/4h]. The change in total postprandial fat oxidation (kcal/4h) relative to CON ([DELTA]FO) was significantly and inversely correlated with the change in the total TG area under the curve relative to CON (mg/dL/4h; [DELTA]TG AUC; R2=0.37, p=0.008).
Conclusions: The low carbohydrate composition of the post-exercise meal contributes to lower PPTG and increased fat oxidation, with lower PPTG related to an increase in fat oxidation.
(C) 2014 American College of Sports Medicine