Misleading Interpretations and Public Misinformation on Human Growth Hormone in Athletes

Abstract

The article by Meinhardt and colleagues (1) isimportant and informative. This randomized, controlled trial evalu-ating the independent and synergistic effects of exogenous growthhormone and testosterone on selected physiologic and athletic per-formance measures is a valuable contribution to the scientific litera-ture. It also provides critical evidence to the ongoing social andscientific debate surrounding sports doping.The study shows significant increases in anaerobic work capac-ity, as measured by the Wingate cycle test, after 8 weeks of treatmentwith growth hormone, with and without concurrent testosteroneadministration. Although effect sizes were modest (0.22 to 0.38 forgrowth hormone alone and 0.61 for growth hormone and testoster-one), these findings suggest a previously unreported physiologic ef-fect that has potential implications for athletic performance. Theauthors correctly conclude, however, that the athletic significance ofthese findings is uncertain.Unfortunately, oversights in the presentation of this importantwork have led to erroneous interpretations in the mainstream mediathat compromise its effect and carry dangerous ramifications, espe-cially when viewed by an untrained audience.The characterization of anaerobic work capacity as “sprint ca-pacity” is inaccurate and misleading. Although equivocal supportexists for cycle ergometry as a significant predictor of sprinting per-formance (2, 3), it is widely recognized that additional factors, in-cluding strength and power, are important determinants (4, 5). Tosuggest even semantically that Wingate test performance and sprintcapacity are equivalent measures is wrong.More egregiously, even while acknowledging such limitations,the authors go on to speculate in specific terms how their findings inrecreational athletes translate to 100-meter running times and 50-meter swimming times in world-class competitors: “We do not knowhow an improvement in Wingate test performance translates to per-formance in the sporting field, but we speculate that the approxi-mately 4% increase in sprint capacity that we observed could trans-late to an improvement of 0.4 second in a 10-second sprint over 100meters or of 1.2 seconds in a 30-second swim over 50 meters.” Thisclaim is made without basis, evidence, or even a compelling expla-nation. Nonetheless, it forms the featured conclusion of numerousprominent media reports, including this from the