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®, São 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, jumps` number 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.

The aim of this study was to evaluate the curves of cardiorespiratory variables during cardiopulmonary exercise testing (CPET) in soccer players who had acute alterations in the glomerular filtration rate (GFR) after performing the pre-season training protocol. Sixteen male professional soccer players (25 ± 3 years; 179 ± 2 cm; and 77 ± 6 kg) were evaluated for oxygen uptake (VO2), heart rate (HR) and pulse relative oxygen (relative O2 Pulse) curves with intervals corresponding to 10% of the total duration of CPET. Athletes were grouped according to the GFR and classified as decreased GFR (dGFR; n = 8) and normal GFR (nGFR; n = 8). Athletes from the dGFR group exhibited lower VO2 values (p < 0.05) when 90% (dGFR 49.8 ± 4.0 vs. nGFR 54.4 ± 6.1 ml·kg-1·min-1) and 100% (dGFR 52.6 ± 4.1 vs. nGFR 57.4 ± 5.9 ml·kg-1·min-1) of the test was complete; HR high values (p < 0.05) when 90% (dGFR 183.7 ± 5.1 vs. nGFR 176.6 ± 4.8 bpm-1) and 100% (dGFR 188.1 ± 5.0 vs. nGFR 180.8 ± 4.8 bpm-1) of the test was complete; and lower relative O2 Pulse values (p < 0.05) when 70% (dGFR 25.6 ± 8.4 vs. nGFR 27.9 ± 9.7 ml·beat-1·kg-1), 80% (dGFR 26.6 ± 8.8 vs. nGFR 29.1 ± 10.0 ml·beat-1·kg-1), 90% (dGFR 27.1 ± 9.0 vs. nGFR 30.8 ± 10.6 ml·beat-1·kg-1) and 100% (dGFR 28 ± 9.2 vs. nGFR 31.8 ± 10.9 ml·beat-1·kg-1) of the test was complete. A correlation was found (r = −0.66, R2 = 0.44, p = 0.00) between lower VO2 peak and elevated levels of urinary protein excretion. In conclusion, soccer players with reduced kidney function after performing the pre-season training protocol also presented alterations in cardiopulmonary variables. We suggest that monitoring of renal function may be used to identify less conditioned soccer players.

Identificar a prevalência de excesso de peso e obesidade abdominal de forma isolada e combinada em escolares de 6 a 10 anos de idade. Participaram do estudo 1267 escolares do município de Macaé, RJ, Brasil. Os dados antropométricos analisados foram a massa corporal, a estatura, e a perimetria da cintura (PC). Os critérios da Organização Mundial da Saúde (OMS) foram usados para definir o sobrepeso e a obesidade. A obesidade abdominal (OA) foi estimada pela relação cintura/estatura (RCEst) ≥0,50. A prevalência de excesso de peso e obesidade nos escolares foi de 33,8% e 16,4%, respectivamente. A prevalência de OA foi de 22,7%, sendo 11,9% meninas e 10,8% meninos (p>0,05). Verificamos que 37,7 % das crianças com sobrepeso apresentam OA, sendo mais presente entre as meninas em comparação com os meninos (50% vs. 26,3%, respetivamente; p

Introduction: The aim of this study was to test the hypothesis that caffeine supplementation (6 mg·kg-1 body mass) for 4-days, followed by acute intake, would impact five male triathletes output power after performed submaximal intensity exercise. Methods: This was a randomized, double-blind, placebo-controlled crossover study, placebo (4-day) - placebo (acute) PP, placebo (4-days) -caffeine (acute) PC, and caffeine (4-day) - caffeine (acute) CC. Participants abstained from dietary caffeine sources for 4 days and ingested capsules containing either placebo or caffeine (6 mg.kg-1 body mass day in one absorption). The acute trials the capsules containing placebo or caffeine (6 mg.kg-1 body mass day in one absorption) were ingested 60min before completing exercise in a treadmill for 40min (80% VO2max) and to perform the Wingate test. Results: Blood lactate was determined before, 60min after ingestion, and immediately after the exercise on the treadmill, the Wingate test, and after the recovery (10-min). CC and PC trials did not change the cardiopulmonary variables (P>0.05) and the anaerobic power variables (peak/mean power output and fatigue index) (P>0.05). The PC trial compared with PP promoted improvements in the curve power output in 2 sec by 31.19% (large effect-size d = 1.08; P<0.05) and 3 sec by 20% (large effect-size d = 1.19; P<0.05). A 10min recovery was not sufficient to reduce blood lactate concentration in the PC trial compared with PP (PC, 13.73±2.66 vs. PP, 10.26±1.60 mmol.L-1; P<0.05, respectively) (P<0.05). Conclusion: In conclusion, these results indicate that caffeine supplementation (6 mg·kg-1 body mass) for 4 days, followed by acute ingestion, did not impact the triathletes output power after performed submaximal intensity exercise. Nutritional interventions may help researchers and athletes to adapt strategies for manipulating caffeine use.Key-words: caffeine metabolism, Wingate test, blood lactate, performance.

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