Impact of GH administration on athletic performance in healthy young adults: A systematic review and meta-analysis of placebo-controlled trials.

OBJECTIVE: Illicit use of growth hormone (GH) as a performance-enhancing drug among athletes is prevalent, although the evidence of such effects in healthy, young subjects is sparse. We therefore performed a meta-analysis of published studies on the effect of GH administration on body composition, substrate metabolism, and athletic performance in healthy, young subjects.

DESIGN: The English-language based databases PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were searched, and eligible articles were reviewed in accordance with the PRISMA guidelines. Fifty-four potentially relevant articles were retrieved of which 11 were included in this analysis comprising 254 subjects.

RESULTS: Administration of GH significantly increased lean body mass (p<0.01) and decreased fat mass (p<0.01). In addition, GH increased the exercising levels of glycerol (p=0.01) and free fatty acids (p<0.01), but did not alter the respiratory quotient during exercise (p=0.30). GH significantly increased anaerobic exercise capacity (p<0.01) in the only study which investigated this, but did not over weeks to months improve muscle strength (p=0.36) or maximum oxygen uptake (p=0.89).

CONCLUSION: GH administration elicits significant changes in body composition, but does not increase either muscle strength or aerobic exercise capacity in healthy, young subjects.