[latin capital V with dot above]o2max and ventilatory threshold of trained cyclists are not affected by 28-day l-arginine supplementation

• Autores: Kyle L. Sunderland, Felicia Greer, Jacobo Morales
• Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 25, Nº. 3, 2011, págs. 833-837
• Idioma: inglés
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• Resumen

  • The ergogenic effect of l-arginine on an endurance-trained population is not well studied. The few studies that have investigated l-arginine on this population have not been conducted in a laboratory setting or measured aerobic variables. The purpose of the current study is to determine if 28 days of l-arginine supplementation in trained male cyclists affects [latin capital V with dot above]o2max and ventilatory threshold (VT). Eighteen (18) endurance-trained male cyclists (mean ± SD, age: 36.3±7.9 years; height: 182.4 ± 4.6 cm; and body mass: 79.5 ± 4.7 kg) performed a graded exercise test (GXT; 50 W + 25 W·min-1) before and after 28 days of supplementation with l-arginine (ARG; 2 × 6 g·d-1) or placebo (PLA; cornstarch). The GXT was conducted on the subject's own bicycle using the RacerMate CompuTrainer (Seattle, WA, USA). [latin capital V with dot above]o2 was continuously recorded using the ParvoMedics TrueOne 2400 metabolic cart (Salt Lake City, UT, USA) and VT was established by plotting the ventilatory equivalent for O2 ([latin capital V with dot above]E/[latin capital V with dot above]o2) and the ventilatory equivalent for CO2 ([latin capital V with dot above]E/[latin capital V with dot above]co2) and identifying the point at which [latin capital V with dot above]E/[latin capital V with dot above]o2 increases with no substantial changes in [latin capital V with dot above]E/[latin capital V with dot above]co2. l-arginine supplementation had no effect from initial [latin capital V with dot above]o2max (PL, 58.7 ± 7.1 ml·kg-1·min-1; ARG, 63.5 ± 7.3 ml·kg-1·min-1) to postsupplement [latin capital V with dot above]o2max (PL, 58.9 ± 6.0 ml·kg-1·min-1; ARG, 63.2 ± 7.2 ml·kg-1·min-1). Also, no effect was seen from initial VT (PL, 75.7 ± 4.6% [latin capital V with dot above]o2max; ARG, 76.0 ± 5.3% [latin capital V with dot above]o2max) to postsupplement VT (PL, 74.3 ± 8.1% [latin capital V with dot above]o2max; ARG, 74.2 ± 6.4% [latin capital V with dot above]o2max). These results indicate that l-arginine does not impact [latin capital V with dot above]o2max or VT in trained male cyclists.