RESUMEN
To determine if photobiomodulation (PBM) has ergogenic effects on the anaerobic performance of well-trained cyclists. Fifteen healthy male road or mountain bike cyclists participated in this randomized, double-blinded, placebo-controlled, crossover study. Athletes were randomly assigned to receive photobiomodulation (630 nm, 4.6 J/cm2, 6 J per point, 16 points, PBM session) or placebo intervention (PLA session) in the first session. The athletes then performed a 30-s Wingate test to determine mean and peak average power, relative power, mean and peak velocity, mean and peak RPM, fatigue index, total distance, time to peak power, explosive strength, and power drop. After 48 h, athletes returned to the laboratory for the crossover intervention. The repeated-measures ANOVA test followed by Bonferroni post hoc test or Friedman test with Dunn's post hoc test (p < 0.05), and Cohen's d statistic were used for comparisons. Performance in the Wingate test was not significantly different (p > 0.05) between PBM and PLA sessions for any variable. Only a small effect size was detected for time to peak power (-0.40; 1.11 to 0.31) and explosive strength (0.38; -0.34 to 1.09). We conclude that irradiation with red light, under a low energy density, does not promote ergogenic effects on the anaerobic performance of cycling athletes.
Asunto(s)
Rendimiento Atlético , Sustancias para Mejorar el Rendimiento , Humanos , Masculino , Estudios Cruzados , Anaerobiosis , Método Doble Ciego , PoliésteresRESUMEN
INTRODUCTION: The present study aimed to investigate the effects of two high-intensity interval training (HIIT) shuttle-run-based models, over 10 weeks on aerobic, anaerobic, and neuromuscular parameters, and the association of the training load and heart rate variability (HRV) with the change in the measures in young futsal players. METHODS: Eleven young male futsal players (age: 18.5 ± 1.1 years; body mass: 70.5 ± 5.7 kg) participated in this study. This pre-post study design was performed during a typical 10 weeks training period. HIIT sessions were conducted at 86% (HIIT86; n = 6) and 100% (HIIT100; n = 5) of peak speed of the FIET. Additionally, friendly and official matches, technical-tactical and strength-power training sessions were performed. Before and after the training period, all players performed the FIET, treadmill incremental, repeated sprint ability (RSA), sprint 15-m, and vertical jump tests (CMJ and SJ), and the HRV was measured. Training load (TL) was monitored using the session rating of perceived effort. Data analysis was carried out using Bayesian inference methods. RESULTS: The HIIT86 model showed clear improvements for the peak oxygen uptake (VO2peak), peak speed in the treadmill incremental test, first and second ventilatory thresholds, RSA best and mean times, CMJ, and SJ. The HIIT100 model presented distinct advances in VO2peak, peak speed in the treadmill incremental test, RSA mean time, and CMJ. Between HIIT models comparisons showed more favorable probabilities of improvement for HIIT86 than HIIT100 model in all parameters. TL data and HIIT models strongly explained the changes in the RSA mean and best times (R 2 = 0.71 and 0.87, respectively), as well as HRV changes, and HIIT models explained positively VO2peak changes (R 2 = 0.72). All other changes in the parameters were low to moderately explained. CONCLUSION: The HIIT86 proved to be more effective for improving aerobic, RSA, and neuromuscular parameters than HIIT100 during a typical 10-week futsal training period. So, strength and conditioning specialists prescribing shuttle-run intermittent exercises at submaximal intensities can manage the individual acceleration load imposed on athlete increasing or decreasing either the set duration or the frequency of change of direction during HIIT programming.
RESUMEN
Abstract The aim of this study was to compare the characteristics of somatic maturation, anthropometric and physical performance (vertical jump and aerobic power) in young basketball players of different playing positions (under 13 years) and analyze these relationships using Peak Height Velocity (PHV) as a measure of somatic maturation. For this, 26 male athletes were evaluated. Anthropometric variables were: body mass, standing and sitting height, and length of lower limbs. Maturation was determined by age at PHV. Physical performance was determined by lower limb power (counter movement jump - CMJ) and aerobic power (Intermittent Recovery Test) tests. MANOVA reported significant differences (p<0.05) among playing positions regarding variables Maturity Offset, estimated PHV age, standing height, sitting height, estimated leg length, body mass and Yo-Yo IR1. In addition, it was identified that point guards reached estimated PHV at later age than their peers who act as small forwards and centers. Regarding CMJ, no significant differences were identified among playing positions, but in relation to aerobic power, point guards and small forwards presented higher performance. These findings confirm that maturation has great effect on growth and physical performance measures and the estimated PHV age is an applicable tool in young athletes, mainly aiding professionals in structuring the teaching-learning- training process in this age group.
Resumo O objetivo do presente estudo foi comparar as características de maturação somática, antropométricas e desempenho físico entre as posições de jogo em jogadores de Basquetebol sub-13 e analisar estas relações utilizando o Pico de Velocidade de Crescimento (PVC) como uma medida da maturação somática. Para tanto, 26 atletas do sexo masculino foram avaliados. As variáveis antropométricas foram: massa corporal, estatura em pé e sentado e comprimento de membros inferiores. A maturação foi determinada pela idade do PVC. O desempenho físico foi através dos testes de potência de membros inferiores (salto com contra movimento - CMJ) e potência aeróbia (Yo-Yo IR1). A MANOVA reportou diferenças significativas (p<0,05) entre as posições em quadra nas variáveis Maturity Offset, idade do PVC estimado, estatura, altura sentado, comprimento de pernas estimado (CPE), massa corporal e Yo-Yo IR1. Além disso, foi identificado que os armadores alcançaram o PVC estimado, em uma idade mais tarde que seus companheiros que atuam como alas e pivôs. Em relação ao CMJ não foram identificadas diferenças significativas entre as posições, já em relação a potência aeróbia, os armadores e alas apresentaram desempenho significativo superior quando comparados aos pivôs. Estes achados confirmam que a maturação tem um grande efeito nas medidas de crescimento e desempenho físico e a determinação da idade estimada do PVC apresenta-se como uma ferramenta aplicável em jovens atletas, principalmente no auxílio de profissionais na estruturação do processo de ensino-aprendizagem-treinamento nesta faixa etária.
RESUMEN
O objetivo deste estudo foi comparar a concordância entre dois indicadores de obesidade, IMC e percentual de gordura, em escolares de ambos os sexos. Para tanto, 100 meninas e 100 meninos de 8 a 10 anos, alunos do ensino fundamental do município de Londrina, foram submetidos a medidas antropométricas para subseqüente cálculo do Índice de Massa Corporal (IMC) e percentual de gordura como indicadores de obesidade. As variáveis foram analisadas em relação aos critérios de referência apresentados por Williams et al6 e Cole et al7. Os resultados foram analisados pelo índice Kappa, evidenciando que 79% dos meninos e 85% das meninas foram classificados simultaneamente pelos dois procedimentos. Uma concordância moderada entre os dois indicadores de obesidade na classificação para meninos e meninas foi evidenciada (kappa=0,43 e 0,50, respectivamente). Entretanto, os dados encontrados demonstraram que 21% dos meninos e 15% das meninas encontravam-se dentro de uma faixa de peso considerada normal, segundo o IMC, contudo, de acordo com o percentual de gordura corporal, apresentavam um quadro de obesidade. Os resultados demonstraram que o IMC, quando comparado ao percentual de gordura, apresentou concordância moderada para classificar crianças de ambos os sexos, de 8 a 10 anos, em relação à obesidade, acima e dentro do critério de referência para saúde.
The aim of this study was to compare the concordance of two obesity indicators, BMI and % body fat in boys and girls. Therefore, 100 girls and 100 boys, with ages ranging from 8 to 10 years, were submitted to anthropometric measurements for subsequent calculation of Body Mass Index (BMI) and % body fat, both as obesity indicators. The variables were analyzed with relation to the reference criteria proposed by Williams et al6 and Cole et al7. The results were then analyzed with the kappa index, elucidating that 79% of the boys and 85% of the girls were classified simultaneously by both procedures. The kappa index indicated a moderate agreement between the two obesity indicators for obese and non-obese classification. However, our data demonstrated that 21% of the boys and 15% of the girls showed normal weight according to BMI, but were classified as obese according to the % body fat. The results show that BMI, when compared with skinfolds, had moderate agreement in children from 8 to 10 years old for detecting obesity.