May 27/Health & Medicine Week -- "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 two weeks of ingestion of food containing a small amount (6g) of MCT on energy metabolism during moderate-intensity exercise and high-intensity exercise in recreational athletes," scientists in Kanagawa, Japan, report.
"For comparison, the subjects were administered food containing MCT or LCT for 14 days and were instructed to perform cycle ergometer exercise at a workload corresponding to 60% peak O-2 uptake (V) over dotO(2)) for 40 minutes, followed by a workload corresponding to 80% peak (V) over dotO(2) until exhaustion. Blood lactate concentration, (V) over dotO(2), (V) over dotCO(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 (V) over dotO(2) was significantly (p &t;0.05) longer in the MCT trial (10.2 +/- 7.6 min: mean +/- SD) than in the LCT trial (5.8 +/- 3.3 min). Blood lactate concentration and RPE during exercise were significantly (p &t;0.05) lower after ingestion of MCT-containing food. Fat oxidation rate was higher and carbohydrate oxidation rate was lower during exercise in the MCT trial than in the LCT trial, but the differences were not significant," wrote N. Nosaka and colleagues.