Acute endurance exercise has been shown to lower postprandial plasma triglyceride (PPTG) concentrations; however, whether this is due to the negative energy and/or CHO deficit from the exercise bout is not well understood.
Purpose: This study aimed to examine the effects of a postexercise meal consisting of either high or low CHO 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) nonexercise control (CON), 2) 80 min of cycling with either no meal replacement (EX), 3) a high-CHO postexercise meal (EX+HCHO), or a 4) low-CHO postexercise meal (EX+LCHO). A standardized meal for PPTG determination was provided (16.0 kcal·kg−1 body mass, 1.02 g fat·kg−1, 1.36 g CHO·kg−1, 0.31 g protein·kg−1) 12 h after the exercise, and measurements of plasma triglyceride (TG) concentration and whole-body resting fat oxidation were made in the fasted condition and during the 4-h postprandial period.
Results: The total area under the curve for plasma TG was significantly lower in EX+LCHO (325 (63) mg·dL−1 per 4 h) compared with that in EX+HCHO (449 (118) mg·dL−1 per 4 h, P = 0.03). Postprandial fat oxidation during this period was significantly greater in EX+LCHO (257 (58) kcal per 4 h, P = 0.003) compared with that in EX+HCHO (209 (56) kcal per 4 h). The change in total postprandial fat oxidation (kcal per 4 h) relative to CON was significantly and inversely correlated with the change in the total TG area under the curve relative to CON (mg·dL−1 per 4 h, ΔTG AUC, R2 = 0.37, P = 0.008).
Conclusions: The low CHO composition of the postexercise meal contributes to lower PPTG and increased fat oxidation, with lower PPTG related to an increase in fat oxidation.