This Article Full Text Full Text (PDF) All Versions of this Article: 90/6/3268    most recent Author Manuscript (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Berggren, A. Articles by Caidahl, K. Search for Related Content PubMed PubMed Citation Articles by Berggren, A. Articles by Caidahl, K. Related Collections Calcium and Bone Metabolism Neuroendocrinology and Pituitary

Short-Term Administration of Supraphysiological Recombinant Human Growth Hormone (GH) Does Not Increase Maximum Endurance Exercise Capacity in Healthy, Active Young Men and Women with Normal GH-Insulin-Like Growth Factor I Axes

Departments of Clinical Physiology (A.B., K.C.), Endocrinology (C.E., T.R., B.-Å.B.), and Clinical Nutrition (L.E.), Sahlgrenska University Hospital, SE-41345 Göteborg, Sweden; and Karolinska Institute (K.C.), SE-171 76 Stockholm, Sweden

Address all correspondence and requests for reprints to: Dr. Kenneth Caidahl, Karolinska University Hospital, N2:01, SE-171 76 Stockholm, Sweden. E-mail: kencai{at}ki.se.

Context: Despite the fact that the use of GH as a doping agent in sports is widespread, little is known about its short-term effects.

Objective: The objective was to study the effects of GH on exercise capacity.

Design: A double-blind, placebo-controlled study was used, with a treatment period of 28 d.

Setting: Subjects from general community studied ambulatory at a university hospital.

Participants: Thirty healthy active young normal volunteers (15 women and 15 men) were recruited by local announcement, and all completed the study.

Intervention: All subjects were randomized to receive a low GH dose (0.033 mg/kg·d or 0.1 IU/kg·d), a high GH dose (0.067 mg/kg·d or 0.2 IU/kg·d), or placebo.

Main outcome measures: Power output and oxygen uptake on bicycle exercise were the main outcome measures.

Results: We found no effect of the low or high dosages of GH on maximum oxygen uptake during exercise (mean ± SE for placebo, 45.2 ± 1.6 to 45.2 ± 2.1 ml/kg·min; GH low dose, 42.8 ± 1.6 to 42.8 ± 1.6 ml/kg·min; GH high dose, 44.8 ± 3.4 to 44.8 ± 2.2 ml/kg·min; not significant by two-way ANOVA). Neither was there any effect on maximum achieved power output during exercise or on blood pressure, heart rate, or the electrocardiographic ST level at rest or during exercise. GH significantly increased total body weight (P = 0.028), an effect predominantly ascribed to fluid retention (increased extracellular water volume), whereas muscle mass (as indicated by intracellular water volume) did not change. However, changes in the latter correlated to changes in physical performance, possibly due to different training efforts.

Conclusion: Administration of supraphysiological recombinant human GH during a period of 4 wk does not improve power output or oxygen uptake.

This article has been cited by other articles:

				H. Liu, D. M. Bravata, I. Olkin, A. Friedlander, V. Liu, B. Roberts, E. Bendavid, O. Saynina, S. R. Salpeter, A. M. Garber, et al. Systematic Review: The Effects of Growth Hormone on Athletic Performance Ann Intern Med, May 20, 2008; 148(10): 747 - 758. [Abstract] [Full Text] [PDF]

				J. Gibney, M.-L. Healy, and P. H. Sonksen The Growth Hormone/Insulin-Like Growth Factor-I Axis in Exercise and Sport Endocr. Rev., October 1, 2007; 28(6): 603 - 624. [Abstract] [Full Text] [PDF]

				J. Young, A. Anwar, and C. Milne Strong diabetes * COMMENTARY Br. J. Sports Med., May 1, 2007; 41(5): 335 - 336. [Abstract] [Full Text] [PDF]

				M. L. Healy, J. Gibney, C. Pentecost, P. Croos, D. L. Russell-Jones, P. H. Sonksen, and A. M. Umpleby Effects of High-Dose Growth Hormone on Glucose and Glycerol Metabolism at Rest and during Exercise in Endurance-Trained Athletes J. Clin. Endocrinol. Metab., January 1, 2006; 91(1): 320 - 327. [Abstract] [Full Text] [PDF]