Elmer-English, R., Goedecke, J. H., Schloss, I. C., Noakes, T. D., & Lambert, E. V. (1998). Ingestion of medium-chain triglycerides (MCT) with carbohydrate during steady-state exercise: Effects on exercise metabolism and gastric symptoms. Medicine and Science in Sports and Exercise, 30(5), Supplement abstract 18.

One side effect of MCT and carbohydrate (CHO) ingestion is gastric distress, which may interfere with performance. Previous studies have shown MCT/CHO ingestion to spare muscle glycogen and improve time-trial performance.

Cyclists (N = 9) completed three trials of two hours at 63% VO2peak followed by a simulated 40 km time trial. Ss ingested breakfast (2.7 MJ, 96 gm CHO), and lunch (2.4 MJ, 102 gm CHO) two hours prior to exercise. During the trials Ss consumed in random order test solutions of 10% glucose, 10% glucose + 3.44% MCT, or 10% glucose + 1.72% MCT.

Gastric symptoms only occurred with the high MCT concentration at four hours post-exercise. There were no differences between the conditions in total fat or CHO oxidation or in time trial performance.

Implication. MCT/CHO did not improve time-trial performance nor did it spare endogenous CHO during extended aerobic exercise. High doses of MCT produce gastric distress post-exercise.

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