Ricardo Santos Oliveira

Seasonal Changes in Physical Performance and Heart Rate Variability in High Level Futsal Players

The aim of this study was to determine the changes in physical performance and resting heart rate variability (HRV) in professional futsal players during the pre-season and in-season training periods. 11 athletes took part in the study (age=24.3±2.9 years; height=176.3±5.2 cm; weight=76.1±6.3 kg), and performed a repeated-sprint ability (RSA) test [6×40 m (20+20 m with a 180° change of direction) sprints separated by 20 s of passive recovery] and Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) at 3 different moments (M1=beginning of pre-season; M2=end of pre-season; M3=mid in-season). The HRV indices were assessed at the same moments. After the short pre-season (3-week), mean RSA time (RSAmean) (M1=7.43±0.2 s; M2=7.24±0.2 s; P=0.003), decrement in RSA performance (RSAdecrement) (M1=6.7±0.3%; M2=5.0±0.9%; P=0.001), and Yo-Yo IR1 distance (M1=1.244±298 m; M2=1.491±396 m; P=0.002) were significantly improved (P<0.05). During the in-season (i. e., M3), performance in Yo-Yo IR1 and RSAmean were maintained. In contrast, RSAbest (M2=6.89±0.2 to M3=6.69±0.3; P=0.001) was improved and RSAdecrement (M2=5.0±0.9% to M3=6.6±0.9%; P=0.001) was impaired. At M2, there was an increase in HRV vagal-related indices compared with M1 that was maintained at M3. In conclusion, after a short pre-season, futsal players improved their RSA and Yo-Yo IR1 performance with concomitant improvements in HRV. These indices were maintained during the in-season period while RSAbest was improved and RSAdecrement impaired. Frequent monitoring of these performances and HRV indices may assist with identification of individual training adaptations and/or early signs of maladaption.

Fourier and wavelet spectral analysis of EMG signals in supramaximal constant load dynamic exercise

Frequency domain analyses of changes in electromyographic (EMG) signals over time are frequently used to assess muscle fatigue. Fourier based approaches are typically used in these analyses, yet Fourier analysis assumes signal stationarity, which is unlikely during dynamic contractions. Wavelet based methods of signal analysis do not assume stationarity and may be more appropriate for joint time-frequency domain analysis. The purpose of this study was to compare Short-Time Fourier Transform (STFT) and Continuous Wavelet Transform (CWT) in assessing muscle fatigue in maximal constant load dynamic exercise (100% Wmax). The results of this study indicate that CWT and STFT analyses give similar fatigue estimates (slope of median frequency) in maximal constant load dynamic exercise (P>0.05). However, the results of the variance was significantly lower for at least one of the muscles studied in CWT compared to STFT (P<0.05) indicating more variability in the EMG signal analysis using STFT. Thus, the stationarity assumption may not be the sole factor responsible for affecting the Fourier based estimates.

The Effects of 17 Weeks of Ballet Training on the Autonomic Modulation, Hormonal and General Biochemical Profile of Female Adolescents

Abstract This study aimed to examine the alterations in physiological and biochemical markers, after 17 weeks of ballet training in high level ballet dancers. Twenty four female ballet dancers from 12 to 15 years old took part in the study. The study followed 17 weeks of ballet training and analyzed changes in body composition, the autonomic nervous system and biochemical variables before and after (post) training. The internal training load was obtained using the session rating of perceived exertion (session-RPE) method, calculated as the mean weekly session-RPE, monotony and strain. After 17 weeks of training there were significant increases in body mass, height, lean body mass, total protein, urea, hemoglobin concentration, testosterone and thyroxine. During this period, decreases in relative body fat, uric acid, red blood cells, C-reactive protein, and ferritin were also found. After the training period, the autonomic modulation demonstrated significant positive alterations, such as increases in parasympathetic related indices. Based on the results obtained we concluded that ballet training led to improvements in body composition and autonomic modulation. In general hematological and biochemical variables demonstrated that the training did not have adverse effects on the health state of the adolescents.

Efeito temporal sobre a resposta da percepção subjetiva do esforço

INTRODUCAO: A percepcao subjetiva de esforco da sessao (PSE da sessao) e um metodo de facil aplicacao e de muita utilidade no contexto esportivo, sendo sugerido um periodo de 30 min apos a sessao de treinamento para sua avaliacao; no entanto, nao existem dados empiricos que suportem essa sugestao.OBJETIVO: Verificar a correlacao e a concordância entre a percepcao subjetiva de esforco (PSE) media reportada durante sessoes de treinamento com valores de PSE reportados 5, 15 e 30 min apos o termino das sessoes de treinamento, em atletas de basquetebol de ambos os generos.METODOS: Participaram desse estudo 11 atletas do sexo feminino e nove atletas do sexo masculino. A PSE foi avaliada atraves da escala de PSE CR-10 a cada 20 min durante a sessao de uma hora de treinamento (PSE media da sessao) e 5, 15 ou 30 min apos o termino. Dessa forma, a PSE media de cada sessao de treinamento foi comparada com os valores de PSE reportados 5, 15 e 30 min apos as sessoes.RESULTADOS: Nao houve diferenca significante da PSE media entre as tres sessoes. As maiores correlacoes foram observadas entre PSE media das sessoes 2 e 3 com a PSE reportada 15 e 30 min, apos para homens (r = 0,92 - 0,91) e mulheres (r = 0,75 - 0,82). Os maiores valores de concordância foram verificados entre a PSE media das sessoes 1 e 2 e as reportadas 15 min e 30 min apos para ambos generos.CONCLUSAO: Com base nos resultados, sugerimos que se evite reportar a PSE 5 min apos o termino da sessao. Alem disso, recomendamos reportar a PSE no minimo 15 min e, sobretudo, 30 min apos o termino da sessao.

Efecto temporal sobre la respuesta de la percepción subjetiva del esfuerzo

INTRODUCAO: A percepcao subjetiva de esforco da sessao (PSE da sessao) e um metodo de facil aplicacao e de muita utilidade no contexto esportivo, sendo sugerido um periodo de 30 min apos a sessao de treinamento para sua avaliacao; no entanto, nao existem dados empiricos que suportem essa sugestao.OBJETIVO: Verificar a correlacao e a concordância entre a percepcao subjetiva de esforco (PSE) media reportada durante sessoes de treinamento com valores de PSE reportados 5, 15 e 30 min apos o termino das sessoes de treinamento, em atletas de basquetebol de ambos os generos.METODOS: Participaram desse estudo 11 atletas do sexo feminino e nove atletas do sexo masculino. A PSE foi avaliada atraves da escala de PSE CR-10 a cada 20 min durante a sessao de uma hora de treinamento (PSE media da sessao) e 5, 15 ou 30 min apos o termino. Dessa forma, a PSE media de cada sessao de treinamento foi comparada com os valores de PSE reportados 5, 15 e 30 min apos as sessoes.RESULTADOS: Nao houve diferenca significante da PSE media entre as tres sessoes. As maiores correlacoes foram observadas entre PSE media das sessoes 2 e 3 com a PSE reportada 15 e 30 min, apos para homens (r = 0,92 - 0,91) e mulheres (r = 0,75 - 0,82). Os maiores valores de concordância foram verificados entre a PSE media das sessoes 1 e 2 e as reportadas 15 min e 30 min apos para ambos generos.CONCLUSAO: Com base nos resultados, sugerimos que se evite reportar a PSE 5 min apos o termino da sessao. Alem disso, recomendamos reportar a PSE no minimo 15 min e, sobretudo, 30 min apos o termino da sessao.

Temporal effect on the response of subjective perceived exertion

INTRODUCAO: A percepcao subjetiva de esforco da sessao (PSE da sessao) e um metodo de facil aplicacao e de muita utilidade no contexto esportivo, sendo sugerido um periodo de 30 min apos a sessao de treinamento para sua avaliacao; no entanto, nao existem dados empiricos que suportem essa sugestao.OBJETIVO: Verificar a correlacao e a concordância entre a percepcao subjetiva de esforco (PSE) media reportada durante sessoes de treinamento com valores de PSE reportados 5, 15 e 30 min apos o termino das sessoes de treinamento, em atletas de basquetebol de ambos os generos.METODOS: Participaram desse estudo 11 atletas do sexo feminino e nove atletas do sexo masculino. A PSE foi avaliada atraves da escala de PSE CR-10 a cada 20 min durante a sessao de uma hora de treinamento (PSE media da sessao) e 5, 15 ou 30 min apos o termino. Dessa forma, a PSE media de cada sessao de treinamento foi comparada com os valores de PSE reportados 5, 15 e 30 min apos as sessoes.RESULTADOS: Nao houve diferenca significante da PSE media entre as tres sessoes. As maiores correlacoes foram observadas entre PSE media das sessoes 2 e 3 com a PSE reportada 15 e 30 min, apos para homens (r = 0,92 - 0,91) e mulheres (r = 0,75 - 0,82). Os maiores valores de concordância foram verificados entre a PSE media das sessoes 1 e 2 e as reportadas 15 min e 30 min apos para ambos generos.CONCLUSAO: Com base nos resultados, sugerimos que se evite reportar a PSE 5 min apos o termino da sessao. Alem disso, recomendamos reportar a PSE no minimo 15 min e, sobretudo, 30 min apos o termino da sessao.