Effect of Ingestion of Medium-Chain Triacylglycerols on Moderate- and High-Intensity Exercise in Recreational Athletes

Medium-chain triacylglycerols (MCT) are known to hydrolyze readily and completely to fatty acids and to be metabolized more easily by beta-oxidation than long-chain triacylglycerols (LCT). Therefore, we investigated the effect of 2 wk of ingestion of food containing a small amount (6 g) of MCT on energy metabolism during moderate-intensity exercise and high-intensity exercise in recreational athletes. For comparison, the subjects were administered food containing MCT or LCT for 14 d, and were instructed to perform cycle ergometer exercise at a workload corresponding to 60% peak O(2) uptake (VO(2)) for 40 min followed by a workload corresponding to 80% peak VO(2) until exhaustion. Blood lactate concentration, VO(2), VCO(2), and rating of perceived exertion (RPE) were measured at rest and during exercise. The exercise time to exhaustion at a workload corresponding to 80% peak VO(2) was significantly (p