BACKGROUND: Growth hormone (GH) helps maintain body composition and metabolism in adults. However, basal and peak GH decline with age. Exercise produces a physiologic GH response that is subnormal in elderly people. Arginine (Arg) infusion can augment GH secretion, but the efficacy of oral Arg to improve GH response to exercise has not been explored. We investigated whether oral Arg increases GH secretion in young and old people at rest and during exercise. METHODS: Twenty young (Y: 22.1 +/- 0.9 y; SEM) and 8 old (O: 68.5 +/- 2.1 y) male and female subjects underwent three different trials following determination of their one-repetition maximum strength (1-RM); exercise only (EO; 3 sets, 8-10 reps at 85% of 1-RM; on 12 separate resistive lifts), Arg only (5.0 g), or Arg + exercise. Blood samples were collected between successive lifts, and GH (ng x ml(-1)) was determined via RIA. RESULTS: In Y vs O: Basal GH secreted (area under the curve) was 543.6 +/- 84.0 vs 211.5 +/- 63.0. During EO, values were 986.6 +/- 156.6 and 517.8 +/- 85.5. Both were significantly lower in the older individuals (p < .05). Oral Arg alone did not result in any increase in GH secretion at rest (310.8 +/- 73.2 vs 262.9 +/- 141.2). When Arg was coadministered during exercise, GH release was not affected in either the young or old and appeared to be blunted in the young compared to the exercise only trial in the young. CONCLUSION: Based upon these findings, we concluded that oral Arg does not stimulate GH secretion and may impair GH release during resistive exercise.

Lo que viene diciendo es que la arginina no estimula la secrecion de hormona de crecimiento y puede entorpecer la secrecion de hormona de crecimiento post entrenamiento...




Fuente:http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&li st_uids=10496544&query_hl=119

El estimulo que ejerce sobre la secrecion sobre la HG es infimo indepedientemente de las dosis y de la hora que lo tomes.

Yo la arginina(en formas mas bioasimilables) la utilizo para otros fines, es un aminoacido muy interesante...

__________________

Cuales fines?

La arginina es un aminoacido que se le conoce tambien por ser precuror del oxido nitrico, actualmente la L-arginina casi ni se usa, se suele usar AAKG(Arginina Alfa Keto Glutarato), arginina Malica, esterificada...

Cuando tienes niveles altos de oxido nitrico en el cuerpo mejoras la circulacion sanguinea facilitando el transporte de nutrientes y la eliminacion de desechos fomentando asi la recuperacion muscular, de echo la forma logica de usarla seria para fomentar la recuperacion.

Suele ser mas util en restriccion calorica o en rutinas con un muy alto volumen de entreno, aerobicos...la he probado y ayuda tanto en el entreno como despues de el.

Se suele combinar con citrulina, beta-alanina, aspirina, ornitina, etc etc....todos ellos a su maneras precursores del NO...

Como dato personal te dire que si lo juntas con tribulus tendras una "viagra" de lo mas util, de echo lo tuve que dejar de tomar por que era horrible

Como pega, no he encontrado ni un solo estudio que asegure que estos precursores del NO no sean perjudiciales para la salud a largo plazo

__________________