Contents lists available at ScienceDirect Respiratory Physiology & Neurobiology journal homepage: www.elsevier.com/locate/resphysiol Medium term effects of physical conditioning on breath-hold diving performance F.A. Fernandez a, ⁎ , R. Martin-Martin b , I. García-Camacha b , D. Juarez c , P. Fidel b , J.M. González-Ravé c a Breatherapy, Faculty of Health, CSEU La Salle, Madrid, Spain b Statistics and Operational Research Area, University of Castilla-la Mancha, Toledo, Spain c Faculty of Sports Sciences, University of Castilla-La Mancha, Toledo, Spain ARTICLE INFO Keywords: Apnea Hypoxia Training Respiratory ABSTRACT The current study aimed to analyze the effects of physical conditioning inclusion on apnea performance after a 22-week structured apnea training program. Twenty-nine male breath-hold divers participated and were allo- cated into: (1) cross-training in apnea and physical activity (CT; n = 10); (2) apnea training only (AT; n = 10); and control group (CG; n = 9). Measures were static apnea (STA), dynamic with fins (DYN) and dynamic no fins (DNF) performance, body composition, hemoglobin, vital capacity (VC), maximal aerobic capacity (VO2max), resting metabolic rate, oxygen saturation, and pulse during a static apnea in dry conditions at baseline and after the intervention. Total performance, referred as POINTS (constructed from the variables STA, DNF and DYN) was used as a global performance variable on apnea indoor diving. + 30, +26 vs. + 4 average POINTS of difference after-before training for CT, AT and CG respectively were found. After a discriminant analysis, CT appears to be the most appropriate for DNF performance. The post-hoc analysis determined that the CT was the only group in which the difference of means was significant before and after training for the VC (p < 0.01) and VO 2max (p < 0.05) variables. Inclusion of physical activity in apnea training increased VC and VO2max in breath hold divers; divers who followed a mixed training, physical training and hypoxic training, achieved increased DNF performance. 1. Introduction In apnea indoor diving competition, breath-hold diverscompete to remain immersed as long as possible in static apnea (STA), and to dive the longest distance in the categories dynamic with fins (DYN) and dynamic no fins (DNF). Adverse effects, such as decompression sickness (Batle, 1999), narcosis or arterial embolism (Batle, 2002), observed during deep events, are not going to occur in the pool practice where the diver submerges barely 2 m; thus, hypoxic syncope is the main risk during apnea indoor practice (Fitz-Clarke, 2006). Recent improvements in equipment, nutrition, and training have led to increases in apnea performance (Schagatay, 2009, 2010; Fernández, 2015). Practice and training is mainly responsible for performance in breath-hold divers; however, it is difficult to establish a rigid training model that suits all divers with different levels of ability, age, previous physical condition or anthropometry. The effects of physical activity on apnea performance have not been clarified, probably because the effects of physical training and apnea training were studied independently. The effects of physical training on apnea performance are controversial. While Bavagad showed in his study (Bagavad, 2014) a correlation between physical conditioning with apnea performance, Schagatay (Schagatay, 2000) did not find effects on apnea performance; however, this latter research concluded that physical training increased stamina, allowing prolongation of the struggle phase of apnea. In addition, a few longitudinal research studies of apnea training have been conducted (Schagatay, 2000; Bagavad, 2014; Fernández, 2015). The current study aimed to analyze the effects of physical conditioning inclusion on apnea performance after a 22- week structured apnea training program. 2. Materials and methods 2.1. Participants Twenty-nine male breath-hold divers (36 ± 5 years of age) with two years of experience in breath-hold diving were divided in different https://doi.org/10.1016/j.resp.2018.07.013 Received 30 April 2018; Received in revised form 26 July 2018; Accepted 30 July 2018 ⁎ Corresponding author. E-mail address: frandeasis@lasallecampus.es (F.A. Fernandez). Respiratory Physiology & Neurobiology 259 (2019) 70–74 Available online 03 August 2018 1569-9048/ © 2018 Elsevier B.V. All rights reserved. T