Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/22610
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dc.contributor.authorvan, der Merwe Johann-
dc.contributor.authorBrooks, Naomi-
dc.contributor.authorMyburgh, Kathryn H-
dc.date.accessioned2016-09-10T23:41:50Z-
dc.date.issued2009-09-
dc.identifier.urihttp://hdl.handle.net/1893/22610-
dc.description.abstractObjective: This study investigated resting concentrations of selected androgens after 3 weeks of creatine supplementation in male rugby players. It was hypothesized that the ratio of dihydrotestosterone (DHT, a biologically more active androgen) to testosterone (T) would change with creatine supplementation. Design: Double-blind placebo-controlled crossover study with a 6-week washout period. Setting: Rugby Institute in South Africa. Participants: College-aged rugby players (n = 20) volunteered for the study, which took place during the competitive season. Interventions: Subjects loaded with creatine (25 g/day creatine with 25 g/day glucose) or placebo (50 g/day glucose) for 7 days followed by 14 days of maintenance (5 g/day creatine with 25 g/day glucose or 30 g/day glucose placebo). Main Outcome Measures: Serum T and DHT were measured and ratio calculated at baseline and after 7 days and 21 days of creatine supplementation (or placebo). Body composition measurements were taken at each time point. Results: After 7 days of creatine loading, or a further 14 days of creatine maintenance dose, serum T levels did not change. However, levels of DHT increased by 56% after 7 days of creatine loading and remained 40% above baseline after 14 days maintenance (P < 0.001). The ratio of DHT:T also increased by 36% after 7 days creatine supplementation and remained elevated by 22% after the maintenance dose (P < 0.01). Conclusions: Creatine supplementation may, in part, act through an increased rate of conversion of T to DHT. Further investigation is warranted as a result of the high frequency of individuals using creatine supplementation and the long-term safety of alterations in circulating androgen composition. Statement of Clinical Relevance: Although creatine is a widely used ergogenic aid, the mechanisms of action are incompletely understood, particularly in relation to dihydrotestosterone, and therefore the long-term clinical safety cannot be guaranteed.en_UK
dc.language.isoen-
dc.publisherLippincott, Williams & Wilkins-
dc.relationvan der Merwe J, Brooks N & Myburgh KH (2009) Three Weeks of Creatine Monohydrate Supplementation Affects Dihydrotestosterone to Testosterone Ratio in College-Aged Rugby Players, Clinical Journal of Sport Medicine, 19 (5), pp. 399-404.-
dc.rightsThe publisher does not allow this work to be made publicly available in this Repository. Please use the Request a Copy feature at the foot of the Repository record to request a copy directly from the author. You can only request a copy if you wish to use this work for your own research or private study.-
dc.subjectcreatine supplementationen_UK
dc.subjectrugby playeren_UK
dc.subjectathleteen_UK
dc.subjectclinical safetyen_UK
dc.subjectDHT:T ratioen_UK
dc.titleThree Weeks of Creatine Monohydrate Supplementation Affects Dihydrotestosterone to Testosterone Ratio in College-Aged Rugby Playersen_UK
dc.typeJournal Articleen_UK
dc.rights.embargodate2999-12-31T00:00:00Z-
dc.rights.embargoreasonThe publisher does not allow this work to be made publicly available in this Repository therefore there is an embargo on the full text of the work.-
dc.identifier.doihttp://dx.doi.org/10.1097/JSM.0b013e3181b8b52f-
dc.identifier.pmid19741313-
dc.citation.jtitleClinical Journal of Sport Medicine-
dc.citation.issn1050-642X-
dc.citation.volume19-
dc.citation.issue5-
dc.citation.spage399-
dc.citation.epage404-
dc.citation.publicationstatusPublished-
dc.citation.peerreviewedRefereed-
dc.type.statusPublisher version (final published refereed version)-
dc.author.emailn.e.brooks@stir.ac.uk-
dc.contributor.affiliationUniversity of Stellenbosch, South Africa-
dc.contributor.affiliationSport-
dc.contributor.affiliationUniversity of Stellenbosch, South Africa-
dc.rights.embargoterms2999-12-31-
dc.rights.embargoliftdate2999-12-31-
dc.identifier.isi000269714200009-
Appears in Collections:Faculty of Health Sciences and Sport Journal Articles

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