Please cite this article in press as: Jacob C, et al. Pre-exercise hyperventilation can significantly increase performance in the 50-meter front crawl. Sci sports (2015), http://dx.doi.org/10.1016/j.scispo.2015.02.006 ARTICLE IN PRESS +Model SCISPO-2926; No. of Pages 4 Science & Sports (2015) xxx, xxx—xxx Disponible en ligne sur ScienceDirect www.sciencedirect.com BRIEF NOTE Pre-exercise hyperventilation can significantly increase performance in the 50-meter front crawl Une hyperventilation pré-exercice peut significativement améliorer les performances lors du 50-mètre crawl C. Jacob b , C. Keyrouz a , N. Bideau a , G. Nicolas a , R. El Hage b,* , B. Bideau a , H. Zouhal a a Laboratoire de physiologie et de biomécanique de l’exercice musculaire, UFR, APS, université de Rennes 2, ENS Cachan, avenue Charles-Tillon, 35043 Rennes cedex, France b Laboratoire de physiologie et biomécanique de l’effort, université de Balamand, PO box 100, Tripoli, Lebanon Received 14 May 2013; accepted 26 February 2015 KEYWORDS Sprint; Fatigue; Swimming; Respiratory alkalosis Summary Objectives. — The aim of this study was to measure the effect of a 30-second pre-exercise maximal voluntary hyperventilation on the performance during a 50 m front crawl. Material and methods. — Nine well-trained swimmers (5 males [21.0 ± 8.5 years, 181.4 ± 3.5 cm, 71.2 ± 3.9 kg] and 4 females [21.0 ± 8.7 years, 166.2 ± 5.0 cm, 55.2 ± 2.2 kg]) performed a 50 m front crawl sprint either in normal conditions (NO) or after hyperventilation (HV) (6 maximal breathing cycles realized in 30 seconds followed by 30 seconds of rest). Results. — Average velocity for the 50 m front crawl was significantly higher after HV (1.81 ± 0.13 m.s -1 vs. 1.79 ± 0.14 m.s -1 , P < 0.01). As a result, performance improves (27.79 ± 2.01 s vs. 28.08 ± 2.17 s, P < 0.01). The number of breathing cycles recorded during each race was significantly lower under HV compared to NO (1.88 ± 0.92 and 2.66 ± 1.41, P < 0.01). Moreover, the first air intake was significantly delayed under HV conditions (29.55 ± 8.67 vs. 23.55 ± 6.10 m, P < 0.01). The stroke rate was slightly increased under HV conditions while stroke length was kept nearly constant. Conclusion. — A pre-exercise maximal voluntary hyperventilation can significantly increase per- formance on the 50 m front crawl in well-trained swimmers. © 2015 Elsevier Masson SAS. All rights reserved. ∗ Corresponding author. Physical education department, faculty of arts and social sciences, university of Balamand, PO box 100, Tripoly, Lebanon. E-mail address: rawadelhage21@hotmail.com (R. El Hage). http://dx.doi.org/10.1016/j.scispo.2015.02.006 0765-1597/© 2015 Elsevier Masson SAS. All rights reserved.