Effects of ingestion of Vespa Amino Acid Mixture under postprandial conditions on blood ketone body concentrations during prolonged exercise in humans

SAITOH Shinichi, TSUCHITA Hiroshi, MUKAI Naoki, and ABE Takashi

This study examined the effects of oral ingestion of Vespa Amino Acid Mixture (VAAM) (Abe., et al., Comp. Biochem. Physiol., 99C:79-84, 1991) on metabolic responses, especially blood ketone body concentrations, to prolonged exercise under postprandial conditions in humans. Six healthy young male subjects exercised on a treadmill at 22%, 55%, and 76% VO2max successively for 15 min each time, totaling 45 min, on two separate occasions.

The subjects had either 380ml of a VAAM drink or a control drink 90 min after lunch and 380 ml during exercise. The VAAM drink contained 10.8 g of amino acid mixture and 38 g of sucrose, and the control drink 48.8 g of sucrose in 760 ml. The exercise started 120 min after lunch.

The ingestion of a VAAM drink significantly increased the concentrations of both serum 3-hydroxybutyrate and acetoacetate pre- and post-exercise, and that of serum glycerol during recovery periods. In the separate experiment, the ingestion of a VAAM drink elevated the level of blood glucagon under the same postprandial conditions.

These findings suggest that an additive effect of exercise and VAAM ingestion might stimulate hepatic ketogenesis and consequently increase blood ketone body concentrations during exercise under postprandial conditions. Furthermore, fat oxidation is still activated during athletic exercise, despite high blood glucose levels (from food digestion).