Relação da maturação biológica com variabilidade da frequência cardíaca e resistência intermitente de jovens futebolistas / Relationship of biological maturation with heart rate variability and intermittent resistance of young soccer players

O objetivo do estudo foi investigar a relação entre maturação biológica, modulação parassimpática da frequência cardíaca e teste de resistência intermitente em jovens jogadores de futebol. Participaram do estudo 23 jovens futebolistas (15,3 ± 1,1 anos, 175 ± 6 cm, 64 ± 7 kg) das categorias sub15 e sub17 de uma equipe da 1ª divisão do campeonato paulista. O estado maturacional foi determinado pela idade do pico de velocidade de crescimento (PVC), usado como indicador relativo de maturidade somática calculada através das medidas de estatura, altura tronco-cefálica, comprimento das pernas, massa corporal e as dobras cutâneas. As medidas de variabilidade da frequência cardíaca (VFC) foram obtidas em repouso durante 5 minutos e, posteriormente, analisadas pela variável raiz quadrada da média dos quadrados das diferenças entre intervalos RR normais adjacentes (rMSSD). Os indivíduos realizaram o teste de resistência intermitente, Yoyo intermittent recovery test level 2 (YIRT 2), após as medidas de VFC terem sido obtidas. Os resultados do presente estudo mostram que não há relação entre modulação parassimpática da frequência cardíaca (rMSSD = 57,4 ± 26,4 ms) e o estado de maturação biológica (0,67 ± 0,81 anos) dos jovens futebolistas (r= 0,30; p=0,163), enquanto que o teste de resistência intermitente (YIRT 2= 658 ± 151 m) possui uma grande correlação com o pico de velocidade de crescimento (r= 0,71; p< 0,001). A modulação parassimpática da frequência cardíaca possui grande correlação com o teste de resistência intermitente dos jogadores (r= 0,54; p= 0,007). Conclui-se que a utilização da idade do PVC e da VFC como indicador de desempenho no YIRT2 em jovens futebolistas....(AU)

The aim of the study was to investigate the relationship between biological maturation, parasympathetic heart rate modulation and intermittent endurance test in young soccer players. Participated of the study 23 young soccer players (15.3 ± 1.1 years, 175 ± 6 cm, 64 ± 7 kg) of the sub15 and sub17 categories of the team from the 1st division championship Paulista. The maturational status was determined by the age of the peak height velocity (PHV), used as relative indicator of somatic maturity and are calculated trhough measures of height, trunk-cephalic height, leg length, body weight, and skinfolds. The Heart rate variability (HRV) measures were obtained in rest during 5 minutes and, posteriorly, analyzed by the variable root mean square of the successive difference (rMSSD). For the intermittent endurance test the subjects performed the Yoyo intermittent recovery test level 2 (YIRT 2), before the HRV measures has been taken. The results of the present study shown which there was not relationship between parasympathetic heart rate modulation (rMSSD = 57,4 ± 26,4 ms) and status biological maturation (0,67 ± 0,81 years) of the young soccer players (r= 0,30; p=0,163), then that the intermittent endurance test (YIRT 2= 658 ± 151 m) has a great correlation with PHV (r= 0,71; p< 0,001). The parasympathetic heart rate modulation has a great correlation with intermittent endurance test of the players (r= 0,54; p= 0,007). In this way, the use of the PHV age and HRV as indicator of performance in YIRT2 in young soccer players is suggested....(AU)

Respiratory muscle strength and aerobic performance of wheelchair basketball players

The respiratory system has been described as a limiting factor in the performance of athletes. Therefore, the objective of this study was to evaluate the relationship between the respiratory muscle strength (RMS) and aerobic performance of wheelchair basketball players (WCBPs). We evaluated 19 male WCBPs who were divided into two groups: trunk control group (TCG) and without trunk control group (WTCG). All participants underwent a pulmonary function test, evaluation of maximal inspiratory (MIP) and expiratory (MEP) pressures, and an aerobic performance test. The MIP of both groups and the MEP values of TCG exceeded the predicted values for age and gender. No differences were observed in the MIP and aerobic performance between the groups although a difference was observed in the MEP values. Positive correlations were observed between MIP/MEP and the aerobic performance for both groups. These results suggested that the overall RMS of this group of WCBPs fell within or above the predicted values. Hence, the study concluded that RMS can positively influence the aerobic performance of WCBP

Interval training based on ventilatory anaerobic threshold increases cardiac vagal modulation and decreases high-sensitivity c-reative protein: randomized clinical trial in coronary artery disease

Background: Autonomic dysfunction and inflammatory activity are involved in the development and progression of coronary artery disease (CAD), and exercise training has been shown to confer a cardiovascular benefit. Objective: To evaluate the effects that interval training (IT) based on ventilatory anaerobic threshold (VAT) has on heart rate variability (HRV) and high-sensitivity C-reactive protein (hs-CRP) levels, as well as the relationship between both levels, in patients with CAD and/or cardiovascular risk factors (RF). Method: Forty-two men (aged 57.88±6.20 years) were divided into two training groups, CAD-T (n= 12) and RF-T (n= 10), and two control groups, CAD-C (n= 10) and RF-C (n=10). Heart rate and RR intervals in the supine position, cardiopulmonary exercise tests, and hs-CRP levels were measured before and after IT. HRV was analyzed by spectral and symbolic analysis. The CAD-T and RF-T underwent a 16-week IT program of three weekly sessions at training intensities based on the VAT. Results: In the RF-T, cardiac sympathetic modulation index and hs-CRP decreased (p<0.02), while cardiac parasympathetic modulation index increased (p<0.02). In the CAD-T, cardiac parasympathetic modulation index increased, while hs-CRP, systolic, and diastolic blood pressures decreased (p<0.02). Both control groups showed increase in hs-CRP parameters (p<0.02). There was a strong and significant association between parasympathetic and sympathetic modulations with hs-CRP. Conclusion: The IT program based on the VAT promoted a decrease in hs-CRP associated with improvement in cardiac autonomic modulation.