Sixteen men completed four trials at random as follows: (Trial A) performance of a single bout of resistance exercise preceded by placebo ingestion (vitamin C); (Trial B) ingestion of 1,500 mg L-arginine and 1,500 mg L-lysine, immediately followed by exercise as in Trial A; (Trial C) ingestion of amino acids as in Trial B and no exercise; (Trial D) placebo ingestion and no exercise. Growth hormone (GH) concentrations were higher at 30,60, and 90 min during the exercise trials (A and B) compared with the resting trials (C and D) (p < .05). No differences were noted in [GH] between the exercise trials. [GH] was significantly elevated during resting conditions 60 min after amino acid ingestion compared with the placebo trial. It was concluded that ingestion of 1,500 mg arginine and 1,500 mg ly sine immediately before resistance exercise does not alter exercise-induced changes in [GH] in young men. However, when the same amino acid mixture is ingested under basal conditions, the acute secretion of GH is increased.
R.R. Suminski is with the Human Performance Laboratory, University of Houston, Houston, TX 77204. R.J. Robertson, F.L. Goss, J. Kang, S. DaSilva, A.C. Utter, and K.F. Metz are with the Human Energy Research Laboratory, University of Pittsburgh, Pittsburgh, PA 15261. S. Arslanian is with the Division of Pediatric Endocrinology, Children’s Hospital of Pittsburgh, Pittsburgh, PA 15261.