12‐weeks of Aquatic Exercise Training modifies mTOR signaling following Essential Amino Acid + Carbohydrate Ingestion in Older Subjects

Essential amino acid (EAA) ingestion can stimulate muscle protein synthesis in young and older subjects. In older subjects however, the addition of carbohydrate (CHO) (EAA+CHO) blunts the anabolic response as compared to young subjects and may be due to dysregulation of the insulin signaling pathway. Recent evidence shows that a single bout of aerobic exercise, performed within 24hrs, restores the anabolic response in older muscle following insulin infusion. PURPOSE: To determine if 12 weeks of aquatic exercise training would similarly maintain the EAA+CHO‐induced anabolic response in older muscle. METODS: Immunoblotting methods were used to determine mTOR signaling, at 1 and 2h post EAA + CHO ingestion pre and post‐training. RESULTS: Our preliminary results from 5 older subjects demonstrate that mTOR phosphorylation is more robust at 1hr post EAA+CHO ingestion following 12 weeks of aquatic training (P<0.05) while there was no change in the phosphorylation status of Akt, S6K1, 4E‐BP1, and eEF2 after training. CONCLUSIONS: Our preliminary findings suggest that mTOR phosphorylation is significantly greater 1hr post EAA+CHO ingestion following 12 weeks of aquatic exercise training as compared to pre‐training. This may provide potential evidence for a beneficial exercise training adaptation which improves the ability of older individuals to respond more efficiently to anabolic nutrients. This work was supported by a Pepper Pilot Project award