Some have suggested that growth hormone is a wonder drug ( 16 ) that results in ripped muscle ( 17 ) and provides stamina-increasing properties ( 18 ) .
The use of human growth hormone to improve athletic performance has recently received worldwide attention .
This practice , often called sports doping , is banned by most professional sports leagues and associations , including the International Olympic Committee , Major League Baseball , and the National Football League ( 13 ) .
However , a wide range of athletes , including those from baseball ( 46 ) , cycling ( 7 , 8) , and track and field ( 5 , 9 ) , have been implicated in or have confessed to illicit growth hormone use .
The Mitchell report ( 10 ) recently identified 89 Major League Baseball players who allegedly used performance-enhancing drugs , and some of these players have subsequently admitted to using growth hormone ( 11 , 12 ) .
Part of the attraction of using growth hormone as a performance enhancer has been that its use is difficult to detect .
The World Anti-Doping Agency , whose formation stemmed from the widely publicized doping sc and al of the 1998 Tour de France ( 13 ) , first used a blood test to detect exogenous growth hormone during the 2004 Olympic Games in Athens .
Although growth hormone is reportedly used to enhance athletic performance and has been called the most anabolic substance known ( 15 ) , its efficacy for this purpose is not well established .
Exogenous growth hormone therapy in growth hormonedeficient adults ( that is , those with growth hormone deficiency due to hypothalamic or pituitary defects ) results in increased lean mass and decreased fat mass ( 19 ) , and comparable body composition changes are seen in healthy elderly adults who receive growth hormone ( 20 ) .
Some experts , however , have suggested that the strength-enhancing properties of growth hormone among healthy adults have been exaggerated ( 15 ) .
Serious side effects , including diabetes , hepatitis , and acute renal failure , may occur in athletes using high-dose growth hormone ( 21 ) .
Furthermore , the use of growth hormone for athletic enhancement is not approved by the U.S. Food and Drug Administration , and the distribution of growth hormone for this purpose is illegal in the United States ( 22 ) .
We performed a systematic review of r and omized , controlled trials to determine the effects of growth hormone therapy on athletic performance in healthy , physically fit , young adults .
Our primary aim was to evaluate the effects of growth hormone on body composition , strength , basal metabolism , and exercise capacity .
In addition , we sought to synthesize the evidence on adverse events associated with growth hormone in the healthy young and assess the quality of the published literature .
Free and total insulin-like growth factors and insulin-like growth factor binding proteins during 14 days of growth hormone administration in healthy adults.
The objective was to investigate the effect of growth hormone ( GH ) administration on circulating levels of free insulin-like growth factors ( IGFs ) in healthy adults . Eight healthy male subjects were given placebo and two doses of GH ( 3 and 6 IU/m2 per day ) for 14 days in a double-blind crossover study . Fasting blood sample s were obtained every second day . Free IGF-I and IGF-II were determined by ultrafiltration of serum . Total IGF-I and IGF-II were measured after acid-ethanol extraction . In addition , GH , insulin , IGF binding protein 1 ( IGFBP-1 ) and IGFBP-3 were measured . Serum-free and total IGF-I increased in a dose-dependent manner during the 14 days of GH administration . After 14 days , serum-free IGF-I values were 610 + /- 100 ng/l ( mean + /- SEM ) ( placebo ) , 2760 + /- 190 ng/l ( 3 IU/ m2 ) and 3720 + /- 240 ng/l ( 6 IU/m2 ) ( p = 0.0001 for 3 and 6 IU/m2 vs placebo ; p = 0.004 for 3 IU/m2 vs 6 IU/m2 ) . Total IGF-I values were 190 + /- 10 micrograms/l ( placebo ) , 525 + /- 10 ( 3 IU/m2 ) , and 655 + /- 40 micrograms/l ( 6 IU/m2 ) ( p < 0.0001 for 3 and 6 IU/m2 vs placebo ; p = 0.04 for 3 IU/m2 ) . There were no differences in the levels of free or total IGF-II during the three study periods . Insulin-like growth factor binding protein 1 was decreased during GH administration ( p = 0.04 for placebo vs 3 IU/m2 ; p = 0.006 for placebo vs 6 IU/m2 ) . In conclusion , fasting serum free IGF-I increased dose dependently during GH administration and free IGF-I increased relatively more than total IGF-I. This may partly be due to the decrease in IGFBP-1
Some have suggested that growth hormone is a wonder drug ( 16 ) that results in ripped muscle ( 17 ) and provides stamina-increasing properties ( 18 ) .
The use of human growth hormone to improve athletic performance has recently received worldwide attention .
This practice , often called sports doping , is banned by most professional sports leagues and associations , including the International Olympic Committee , Major League Baseball , and the National Football League ( 13 ) .
However , a wide range of athletes , including those from baseball ( 46 ) , cycling ( 7 , 8) , and track and field ( 5 , 9 ) , have been implicated in or have confessed to illicit growth hormone use .
The Mitchell report ( 10 ) recently identified 89 Major League Baseball players who allegedly used performance-enhancing drugs , and some of these players have subsequently admitted to using growth hormone ( 11 , 12 ) .
Part of the attraction of using growth hormone as a performance enhancer has been that its use is difficult to detect .
The World Anti-Doping Agency , whose formation stemmed from the widely publicized doping sc and al of the 1998 Tour de France ( 13 ) , first used a blood test to detect exogenous growth hormone during the 2004 Olympic Games in Athens .
Although growth hormone is reportedly used to enhance athletic performance and has been called the most anabolic substance known ( 15 ) , its efficacy for this purpose is not well established .
Exogenous growth hormone therapy in growth hormonedeficient adults ( that is , those with growth hormone deficiency due to hypothalamic or pituitary defects ) results in increased lean mass and decreased fat mass ( 19 ) , and comparable body composition changes are seen in healthy elderly adults who receive growth hormone ( 20 ) .
Some experts , however , have suggested that the strength-enhancing properties of growth hormone among healthy adults have been exaggerated ( 15 ) .
Serious side effects , including diabetes , hepatitis , and acute renal failure , may occur in athletes using high-dose growth hormone ( 21 ) .
Furthermore , the use of growth hormone for athletic enhancement is not approved by the U.S. Food and Drug Administration , and the distribution of growth hormone for this purpose is illegal in the United States ( 22 ) .
We performed a systematic review of r and omized , controlled trials to determine the effects of growth hormone therapy on athletic performance in healthy , physically fit , young adults .
Our primary aim was to evaluate the effects of growth hormone on body composition , strength , basal metabolism , and exercise capacity .
In addition , we sought to synthesize the evidence on adverse events associated with growth hormone in the healthy young and assess the quality of the published literature .