RESULTS Body cell mass was correlated with all measures of performance at baseline .
Growth hormone significantly reduced fat mass , increased lean body mass through an increase in extracellular water , and increased body cell mass in men when coadministered with testosterone .
Growth hormone supplementation influenced body composition and increased sprint capacity when administered alone and in combination with testosterone .
BACKGROUND Growth hormone is widely abused by athletes , frequently with and rogenic steroids .
Its effects on performance are unclear .
OBJECTIVE To determine the effect of growth hormone alone or with testosterone on body composition and measures of performance .
Short-term growth hormone (GH) treatment of GH-deficient adults increases body sodium and extracellular water, but not blood pressure.
Initiation of  GH treatment in adults is frequently complicated by the development of symptomatic fluid retention . To investigate the mechanism and extent of fluid retention that occurs with dosages of GH used in the treatment of GH-deficient adults , we conducted a double blind study in which seven GH-deficient patients ( aged 24 - 74 yr ) each received in r and om order daily sc injections of placebo , a physiological dose of GH ( 0.04 U/kg , low dose ) , and a supraphysiological dose of GH ( 0.08 U/kg , high dose ) for 7 days , separated by 21-day washout periods . On the seventh day , measurements were made of serum insulin-like growth factor I , body weight , exchangeable sodium , plasma volume , angiotensinogen , PRA , aldosterone , atrial natriuretic peptide ( ANP ) , and mean 24-h ambulatory heart rate and blood pressure . GH significantly increased mean insulin-like growth factor I levels from 105 + /- 11 to 304 + /- 45 micrograms/L during low dose treatment ( P = 0.006 ) and 400 + /- 76 micrograms/L during high dose treatment ( P = 0.004 ) . High dose GH caused a 1.2 + /- 0.3 kg increase in body weight ( P = 0.01 ) and a 193 + /- 65 mmol increase in exchangeable sodium ( P = 0.008 ) . Low dose GH had a lesser effect , with no significant increase in body weight , but an increase in exchangeable sodium of 113 + /- 37 mmol ( P = 0.02 ) . Plasma volume was not significantly affected by GH treatment . Mean supine angiotensinogen levels were significantly higher during both GH treatments compared to placebo ( low dose , P = 0.017 ; high dose , P = 0.028 ) as were mean supine PRA levels ( low dose , P = 0.0002 ; high dose , P = 0.0025 ) . Supine angiotensin II , aldosterone , and ANP levels were not significantly affected by GH treatment . There was no significant change from placebo in any of the sodium-regulating hormones in the erect posture . The mean 24-h heart rate was significantly higher during low dose ( 82 + /- 2 beats/min ; P = 0.0001 ) and high dose ( 88 + /- 3 beats/min ; P = 0.0001 ) GH treatment than during placebo ( 67 + /- 3 beats/min ) . However , no significant change in mean 24-h systolic or diastolic blood pressure was observed . In summary , acute GH administration using doses currently employed in treating adults causes a dose-related increase in body weight and body sodium , but no associated increase in blood pressure . We conclude that 1 ) sodium retention is a physiological effect of GH , but does not cause an acute rise in blood pressure ; and 2 ) the mechanism of sodium and fluid retention is not primarily due to enhanced aldosterone secretion or inhibition of ANP release , but more likely to a direct renal tubular effect
RESULTS Body cell mass was correlated with all measures of performance at baseline .
Growth hormone significantly reduced fat mass , increased lean body mass through an increase in extracellular water , and increased body cell mass in men when coadministered with testosterone .
Growth hormone supplementation influenced body composition and increased sprint capacity when administered alone and in combination with testosterone .
BACKGROUND Growth hormone is widely abused by athletes , frequently with and rogenic steroids .
Its effects on performance are unclear .
OBJECTIVE To determine the effect of growth hormone alone or with testosterone on body composition and measures of performance .