Heart Rate Variability Responses in Vertical Jump Performance of Basketball Players

Our objectives were to investigate the acute responses of the heart rate variability (HRV) before, during and after the execution of different Vertical Jump (VJ) protocols and correlate the levels of sympathetic and parasympathetic modulation after the VJ execution with the performance variables in VJ. Eight male athletes (29±4.9 years; 186±8.6 cm; 24.8±2.1 kg.m-2; 12±1.2% body fat) of a team participating in the first division of the National Basketball League (NBL), from Brazil, were evaluated. For the HRV analysis, each subject was instructed to stand in a orthostatic position on the jump platform System Optical (Cefise®, Sao Paulo) for a period of 10 minutes of rest before (R1) and after the VJ executions (R2). Right after the R1 period, athletes performed 5VJ with five seconds intervals (total time ~ 30 seconds) between VJ (5VJ) and then underwent 60 seconds of maximum continuous VJ (60SVJ). The HRV were automatically transferred and analyzed by the softwares "Polar ProTrainer5™" (version 5.41.002., Kempele, Finland) and HRV analisys (version 2.1., Kuopio, Finland), respectively. The HFnu was used to represent the parasympathetic modulation, whereas LFnu represented the sympathetic modulation. The ratio LF:HF was used to represent the balance between sympathetic and parasympathetic modulations. The one-way Analysis of Variance (ANOVA) with post hoc Tukey test was used to compare differences in HRV during the execution of the experimental protocol. Linear regression and Pearson's correlation coefficient were used between the VJ performance variables (mean of 5VJ and 60SVJ, jumpsnumber and fatigue index) and the sympathetic and parasympathetic modulation LF:HF R2 (p< 0.05). The following comparisons of the HRV were found between the different protocols: 5VJ (LF 93.9±5.4 nu) versus R1 (LF 64.2±19.9 nu); 5VJ (HF 6.0±5,4 nu) versus R1 (HF 35.6±19,9 nu); 5VJ (LF:HF 40.1±37.4) versus R1 (LF:HF 2.6±1.9 nu) (p < 0.001); 60SVJ (LF:HF 8.3±13.8 ms²) versus 5VJ (LF:HF 40.1±7.7 ms²); R2 (LF:HF 6.5±5.7 ms²) versus 5VJ (LF:HF 40.1±7.7 ms²) (p < 0.001). A significant correlation was found between the average height of 5VJ with the sympathetic and parasympathetic modulation LF:HF R2 (r = 0.7942 , p = 0.01 ) and fatigue index 60SVJ with the sympathetic and parasympathetic modulation LF:HF R2 (r = 0.7206 , p = 0.04). It is concluded that the 5VJ test characterized by intermittent high intensity loads, showed high significant responses of sympathetic modulation (LF; LF:HF) compared to the 60SVJ protocol. The 5 min recovery was not sufficient for the onset of vagal tone (parasympathetic modulation), which was accompanied by higher fatigue index presented by basketball athletes.