Furthermore, swimmers often compete in several events within a 30–90 min time frame during any given session. Swimmers must also contend with restrictions placed on their breathing frequency during

intense exercise as a result a unique interaction between muscle physiology, technique, and ventilation. Exercise hyperpnoea is limited during high intensity swimming because turning or lifting the head to breathe may Dibutyryl-cAMP clinical trial jeopardize execution of proper stroke technique [17, 18]. Indeed, swimming requires that the athlete sustain a high rate of energy expenditure and the suspension of breathing for approximately 20 – 30% of a race [19]. Given these limitations and the physiological consequences, it is likely that anaerobic metabolism is a significant contributor to metabolic power in competitive swimming, and may also be a primary determinant of fatigue and limitations in performance [7]. Another reason why competitive

swimming is an appropriate model for studying the effectiveness of alkalizing agents is that swimmers are often young when they reach elite level competition; among the swimming medalists in the 2012 Olympics (n = 78), twenty-five were under 21 and eight were under 18 years old. This creates a highly competitive environment, where 80% of elite adolescent athletes are using supplements and other non-doping strategies to improve performance [20]. It is, therefore, surprising that there is such a lack of research on the effectiveness of such ergogenic aids in this www.selleckchem.com/products/z-vad(oh)-fmk.html population [20], especially when acid base regulation in adolescents may be significantly different than that of adults. The overall purpose of this study was to evaluate the ergogenic effect of two Na-CIT supplementation protocols, previously used in adults, in adolescent swimmers. SPTBN5 Specifically, the types of Na-CIT supplementation protocols that have been previously applied include an acute (single) dose and a chronic (multi-day) dose prior to performance. During the acute delivery

mode participants take one single dose (0.3 – 0.6 g∙ kg-1 body mass Na-CIT) 60 to 180 min before the start of competition [2–4, 11, 13] while a chronic dose (0.3 g∙ kg-1 body mass Na-CIT) is given for a number of days prior to performance [21]. Chronic dosing of alkalizing agents was first employed by McNaughton et al. [22] using PF-6463922 nmr sodium bicarbonate in an effort to elicit an ergogenic effect while minimizing GI upset, which often occurs with acute dosing protocols. Based on these studies, a double-blinded, placebo controlled, cross-over design was used to investigate the effects of an acute versus a chronic Na-CIT supplementation protocol on 200 m swimming performance and acid–base parameters in male, adolescent swimmers. Methods Participants Sample size was calculated using pre- and post-trial blood lactate concentrations from a published 5 km run trial in adults, an 80% power, and a 0.05 level of significance; this resulted in a minimum sample size of 8 [13].