The effect of a period of intensive exercise on the isoform test to detect growth hormone doping in sports

Growth Horm IGF Res. 2013 Aug;23(4):105-8. doi: 10.1016/j.ghir.2013.03.006. Epub 2013 Apr 19.

Abstract

Objective: The major objective of this study was to investigate the effects of several days of intense exercise on growth hormone (hGH) testing using the World Anti-Doping Agencies hGH isoform differential immunoassays. Additionally the effects of circadian variation and exercise type on the isoform ratios were also investigated.

Study design: 15 male athletes performed a simulated nine day cycling stage race. Blood samples were collected twice daily over a period of 15 days (stage race+three days before and after). hGH isoforms were analysed by the official WADA immunoassays (CMZ Assay GmbH).

Results: All measured isoform ratios were far below the WADA decision limits for an adverse analytical finding. Changes in the isoform ratios could not be clearly connected to circadian variation, exercise duration or intensity.

Conclusions: The present study demonstrates that the hGH isoform ratios are not significantly affected by exercise or circadian variation. We demonstrated that heavy, long term exercise does not interfere with the decision limits for an adverse analytical finding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Doping in Sports*
  • Exercise / physiology*
  • Human Growth Hormone / administration & dosage
  • Human Growth Hormone / blood*
  • Humans
  • Immunoassay
  • Male
  • Protein Isoforms
  • Substance Abuse Detection / methods*
  • Time Factors

Substances

  • Protein Isoforms
  • Human Growth Hormone