Two-year training program-induced cardiorespiratory developments in adolescent female handball players: The importance of playing position

Abstract As there are few data available, we aimed to assess the development of the cardiorespiratory system of young female athletes following a two-year training program (2y-TP) and explore the game position-specific changes. Methods Before and after the 2y-TP body compositions of young elite female handball players (age: 14.2 ± 0.5 years, n = 33) were investigated by dual-energy x-ray absorptiometry (DEXA). The morphological changes of the heart were assessed by echocardiography, and cardiorespiratory values were investigated by spiroergometry. Results Compared to initial values, after the 2y-TP, significant increases were found in body mass (by 8.8%), skeletal muscle mass (by 7.7%), and body fat (by 11.3%), power (by 7.8%), VO 2 (by 10.6%), VCO 2 (by 8.3%), oxygen pulse (by 13.8%), ventilation (by 13.4%), tidal volume (by 13.7%), left ventricular mass (by 24.8%), stroke volume (by 21.2%), and stroke volume normalized to the body surface (by 16.4%). Heart rate decreased (by 2.9%), whereas respiratory frequency, load time, relative power, and relative VO 2 did not change. During the test, the goalkeepers run for a shorter time than the wing players at the initial time point and after the 2y-TP. Also, the maximum heart rate did not change in goalkeepers, whereas it decreased in wing players after the 2y-TP. Thus, the goalkeepers had a higher initial VO 2 value at VO 2 peak than wing players, and differences, which were maintained after the 2y-TP, as well. In contrast, in goalkeepers, the relative VO 2 at the VO 2 peak was initially lower than in wing players, which remained lower after the 2y-TP, as well. Conclusions In adolescent female handball players, the 2y-TP significantly improved skeletal muscle mass, which corresponded to significant improvements of cardiorespiratory function, which were more accentuated in wing players, compared to goalkeepers, likely due to the different loads during trainings and matches.