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 SB203580 cell line 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 Torin 1 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. Mannose-binding protein-associated serine protease 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 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].