Relação entre indicadores de desidratação e a modulação autonômica de atletas profissionais de futsal masculino

Abstract

Futsal is an intermittent sport involving moments of high intensity followed by moments of active recovery. Given the high physical demand requested by the sport, athletes tend to present dehydration. Considering these factors, they lead to an increase in physiological stress, requiring greater action by the autonomic nervous system to regulate the body’s homeostasis. In this sense, autonomic modulation can be monitored by heart rate variability (HRV). Therefore, the aim of this study was to verify the relation between the indicators of dehydration, the parameters of heart rate variability and the playing time of professional male Futsal athletes in the pre- and postgame conditions. The sample was composed of 13 players with an average age of 23.96 ± 2.99 years with an average height of 173.72 ± 6.81 cm assessed over three competitions. The athletes were evaluated 1h30 min before each match and 20 min later, whose measured variables were: total body mass, body water and the record of RR intervals at rest for later analysis of HRV. Total body mass was measured employing a portable digital platform scale, body water was measured employing the full-body polar tetra bioimpedance method and RR intervals were registered by a system consisted of a small portable sensor powered by a USB cable and a chest transmitter. The Kubios HRV software version 2.2 was used for the analysis and generation of information related to HRV. The data were stored in a Microsoft® Office Excel 2016 spreadsheet and analyzed using BioEstat software version 5.3. The Shapiro-Wilk test was used to verify the normality of the data, which found their symmetry. To test whether there was a significant difference between the pre and postgame data, the student t test for independent samples was approached. Finally, Pearson’s correlation test was performed to verify the interaction between dehydration indicators, heart rate variability parameters and playing time. Data were presented as averages and standard deviations. For all treatments, the significance value was assumed to be p <0.05. The athletes presented dehydration percentage values of 0.81 ± 0.58% due to the loss of total body mass and significant differences (p <0.05) for all HRV parameters between the pre and post-game moments. There were statistically significant correlations (p <0.05) between the interactions ∆SDNN, ∆pNN50 and ∆rMSSD x playing time. This study found out that the athletes presented a high autonomic stress between the pre and post-game conditions, however, this condition was not influenced by the levels of dehydration.