Rr. Suminski et al., ACUTE EFFECT OF AMINO-ACID INGESTION AND RESISTANCE EXERCISE ON PLASMA GROWTH-HORMONE CONCENTRATION IN YOUNG MEN, INT J SP NU, 7(1), 1997, pp. 48-60
Sixteen men completed four trials at random as follows: (Trial A) perf
ormance of a single bout of resistance exercise preceded by placebo in
gestion (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; (Tria
l 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 w
ere noted in [GH] between the exercise trials. [GH] was significantly
elevated during resting conditions 60 min after amino acid ingestion c
ompared with the placebo trial. It was concluded that ingestion of 1,5
00 mg arginine and 1,500 mg lysine immediately before resistance exerc
ise does not alter exercise-induced changes in [GH] in young men. Howe
ver, when the same amino acid mixture is ingested under basal conditio
ns, the acute secretion of GH is increased.