The Effect of Five Weeks of Tribulus terrestris Supplementation on Muscle Strength and Body Composition During Preseason Training in Elite Rugby League Players

• Autores: Shane Rogerson, Christopher Riches, Carl Jennings, Robert P. Weatherby, Rudi A. Meir
• Localización: Journal of strength and conditioning research: The Official Research Journal of the NSCA, ISSN 1064-8011, Vol. 21, Nº. 2, 2007, págs. 348-353
• Idioma: inglés
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• Dialnet Métricas: 3 Citas
• Resumen

  • Rogerson, S., C.J. Riches, C. Jennings, R.P. Weatherby, R.A. Meir, and S.M. Marshall-Gradisnik. The effect of five weeks of Tribulus terrestris supplementation on muscle strength and body composition during preseason training in elite rugby league players. J. Strength Cond. Res. 21(2):348-353. 2007.- Tribulus terrestris is an herbal nutritional supplement that is promoted to produce large gains in strength and lean muscle mass in 5-28 days (15, 18). Although some manufacturers claim T. terrestris will not lead to a positive drug test, others have suggested that T. terrestris may increase the urinary testosterone/epitestosterone (T/E) ratio, which may place athletes at risk of a positive drug test. The purpose of the study was to determine the effect of T. terrestris on strength, fat free mass, and the urinary T/E ratio during 5 weeks of preseason training in elite rugby league players. Twenty-two Australian elite male rugby league players (mean ± SD; age = 19.8 ± 2.9 years; weight = 88.0 ± 9.5 kg) were match-paired and randomly assigned in a double-blind manner to either a T. terrestris (n = 11) or placebo (n = 11) group. All subjects performed structured heavy resistance training as part of the club's preseason preparations. A T. terrestris extract (450 mg·d?1) or placebo capsules were consumed once daily for 5 weeks. Muscular strength, body composition, and the urinary T/E ratio were monitored prior to and after supplementation. After 5 weeks of training, strength and fat free mass increased significantly without any between-group differences. No between-group differences were noted in the urinary T/E ratio. It was concluded that T. terrestris did not produce the large gains in strength or lean muscle mass that many manufacturers claim can be experienced within 5-28 days. Furthermore, T. terrestris did not alter the urinary T/E ratio and would not place an athlete at risk of testing positive based on the World Anti-Doping Agency's urinary T/E ratio limit of 4:1.