Papers by Thiago F D Kanthack
Behavioural Brain Research, 2017
The efficacy of motor imagery (MI) practice to facilitate muscle stretching remains controversial... more The efficacy of motor imagery (MI) practice to facilitate muscle stretching remains controversial and the underlying neurophysiological mechanisms unexplored. We evaluated the effects of MI practice during a sit-and-reach task. Healthy participants were randomly assigned to a MI PRACTICE (n = 15) or CONTROL (n = 15) group and completed 2 blocks of 5 sit-and-reach trials. During the first block (B1), participants performed 5 maximal stretching trials of 10s. During the second block (B2), trials were divided into two consecutive parts: i) reproducing the maximum performance of B1 (10s, B2 PART 1), and ii) attempting to outperform the maximum performance of B1 (10s, B2 PART 2). Participants performed kinesthetic MI of hamstring stretching during B2 trials in the MI PRACTICE group. We recorded electromyography from the hamstring and rectus femoris of the dominant leg. We also processed skin conductance as an index of sympathetic activity. We measured greater performance improvements from B1 to B2 PART 2 in the MI PRACTICE group compared to CONTROL (p < 0.05). Participants in the MI PRACTICE group exhibited reduced hamstring activation during both B2 PART 1 (p < 0.001) and B2 PART 2 (p < 0.001) compared to CONTROL. Skin conductance revealed higher sympathetic activation during B2 PART 2 compared to both B1 and B2 PART 1 in the two groups. Thus, performing MI during actual movement is likely to improve stretching performance through reduced muscle activation. Such improvement may be grounded in a cortical gain over spinal reflexes.
Música: un recurso psicofi siológico para el ejercicio físico y deporte
Archivos De Medicina Del Deporte Revista De La Federacion Espanola De Medicina Del Deporte Y De La Confederacion Iberoamericana De Medicina Del Deporte, 2013
El uso de la musica se ha identifi cado como un auxiliar ergogenico potencial que ayuda a mejorar... more El uso de la musica se ha identifi cado como un auxiliar ergogenico potencial que ayuda a mejorar el rendimiento en el ejercicio. La musica ha sido clasifi cada como una ayuda ergogenica psicologica y ha despertado el interes principalmente por sus efectos encontrados en estudios con un enfoque en el rendimiento durante, antes y despues del ejercicio, En este contexto, el objetivo de este estudio fue revisar la literatura sobre los principales efectos de la musica sobre el rendimiento y sus posibles mecanismos, cubriendo nuevas perspectivas sobre el tema. El metodo consistio en la busqueda, seleccion y estratifi cacion de los articulos originales de grandes bases de datos (Medline, Sport Discuss, Scopus, Web of Science and Scielo) que utilizan los descriptores: musica, ejercicio, rendimiento y fatiga. Se consideraron todos los modelos y tipos de ejercicio y musica. Estos articulos indican que el uso de la musica como un auxiliar ergogenico podria ser efi caz para mejorar el rendimiento; disminuir la tasa de percepcion de esfuerzo y es capaz de ofrecer mejores sensaciones con el ejercicio, de acuerdo con el tiempo de aplicacion, la condicion fisica de los sujetos, el tipo de ejercicio y componentes musicales, respetando algunas recomendaciones y orientaciones para la insercion. Los principales mecanismos de accion propuestos por los efectos ergogenicos de la musica se basan en la hipotesis de comportamiento y se siguen discutiendo; tampoco hay evidencias sufi cientes para descartar cualquiera de ellos, lo que demuestra la necesidad de estudios futurosen un intento por aclarar tales efectos en el sistema nervioso central.Para resumir todo esto, proponemos algunas orientaciones de uso en el ejercicio submaximo y maximo, permitiendo que los entrenadores y atletas aplicar esta tecnica en sus metodos de entrenamiento
PLOS ONE, 2016
There is compelling evidence that motor imagery contributes to improved motor performance, and re... more There is compelling evidence that motor imagery contributes to improved motor performance, and recent work showed that dynamic motor imagery (dMI) might provide additional benefits by comparison with traditional MI practice. However, the efficacy of motor imagery in different states of physical fatigue remains largely unknown, especially as imagery accuracy may be hampered by the physical fatigue states elicited by training. We investigated the effect of static motor imagery (sMI) and dMI on free-throw accuracy in 10 high-level basketball athletes, both in a non-fatigued state (Experiment 1) and immediately after an incremental running test completed until exhaustion (20m shuttle run-test-Experiment 2). We collected perceived exhaustion and heart rate to quantify the subjective experience of fatigue and energy expenditure. We found that dMI brought better shooting performance than sMI, except when athletes were physically exhausted. These findings shed light on the conditions eliciting optimal use of sMI and dMI. In particular, considering that the current physical state affects body representation, performing dMI under fatigue may result in mismatches between actual and predicted body states.
Influência de Diferentes Protocolos de Exercício Cíclico Sobre o Estado de Humor
Revista Brasileira de Ciência e Movimento, 2014
Physical exercise has demonstrated significant and consistent relationship with psychological alt... more Physical exercise has demonstrated significant and consistent relationship with psychological alterations, especially in its chronic intervention which is capable of reducing stress and anxiety levels after uninterrupted practice. The purpose of this study was to evaluate the acute effect of cyclical exercise sessions with different intensities on mood parameters. Six different protocols (several intensities) have been assessed: 30 min of submaximal exercise intensity on cycle simulator - (SC30m); time-trial protocols of several distances of 1km, 5km and 20km (CR1km, CR5km, CR20km); 5km of running (RUN5km) and 100 m of running (100MR). During all protocols, the participants performed a mood assessment using the Brunel Mood Scale (BRUMS) previously and posteriorly tests. All tests relied on samples of athletes or healthy subjects. Significant differences were found in the following domains: anger for CR1Km (pre: 0.00 (0.0); post: 1.00 (3.0); p=0.042); depression for CR1Km (pre: 0.00 (1.0); post: 1.00(1.0); p=0.039) e 100MR (pre: 0.00 (0.8); post: 2.00 (-2.0); p=0.042); and increased fatigue for all protocols, as well as a tension decrease levels for Run5Km (pre: 2.20 (1.8); post: 1.20 (1.3); p= 0.021). We are able to conclude that acute sessions of exercise were capable of changing the mood parameters for specific samples. Furthermore, different protocols and intensities of exercise may promote diversified changes on these parameters. Thereby, our present findings might help coaches to better control the athlete´s psychological state during each training session.
Short-term effects of integrated motor imagery practice on muscle activation and force performance
Neuroscience, 2015
The effect of motor imagery (MI) practice on isometric force development is well-documented. Howe... more The effect of motor imagery (MI) practice on isometric force development is well-documented. However, whether practicing MI during rest periods of physical training improves the forthcoming performance remains unexplored. We involved 18 athletes in a counterbalanced design including three physical training sessions scheduled over five consecutive days. Training involved 10 maximal isometric contractions against a force plate, with the elbow at 90°. During two sessions, we integrated MI practice (focusing on either muscle activation or relaxation) during the inter-trial rest periods. We measured muscle performance from force plate and electromyograms of the biceps brachii and anterior deltoideus. We continuously monitored electrodermal activity (EDA) to control sympathetic nervous system activity. MI of muscle activation resulted in higher isometric force as compared to both MI of muscle relaxation and passive recovery (respectively +2.1% and +3.5%). MI practice of muscle relaxation also outperformed the control condition (+1.9%). Increased activation of the biceps brachii was recorded under both MI practice conditions compared to control. Biceps brachii activation was similar between the two MI practice conditions, but electromyography revealed a marginal trend toward greater activation of the anterior deltoideus during MI practice of muscle activation. EDA and self-reports indicated that these effects were independent from physiological arousal and motivation. These results might account for priming effects of MI practice yielding to higher muscle activation and force performance. Present findings may be of interest for applications in sports training and neurologic rehabilitation.
Archivos de Medicina del Deporte
The use of music has been identified as a potential ergogenic aid that helps to improve performan... more The use of music has been identified as a potential ergogenic aid that helps to improve performance in exercise. Music has been classified as a psychological ergogenic aid and has attracted interest mainly for its effects found in studies with a focus on performance during exercise, pre-task and post-task. In this context, the objective of this study was to review the literature about the main effects of music on performance and their possible mechanisms, covering new perspectives about the theme. The method consisted of search, selection and stratification of the original articles of major databases (Medline, Sport Discuss, Scopus, Web of Science and Scielo) using the descriptors music, exercise, performance and fatigue. We considered all models and types of exercise and music. These articles suggest that the use of music as an ergogenic aid could be efficient to improve performance; decrease rate perceived of exertion and is capable to bring better feelings to exercise, according ...
Motriz: Revista de Educação Física, 2013
The purpose of this study was to compare the prefrontal cortex (PFC) blood flow variation and tim... more The purpose of this study was to compare the prefrontal cortex (PFC) blood flow variation and time on in males and females while performing a motor task and imagery perspectives. Eighteen right handed subjects (11 males and 7 females) were volunteers to this study. All subjects went through three randomly conditions, a motor task condition (MT) in which they had to do a simple finger tap. The other conditions included practicing imagery in first and third views. During all the conditions, the fNIRS device was attached to the subject forehead to obtain the blood flow; the total time in each task which was measured with a chronometer. No difference had been found in any condition for both sexes in the PFC and time, nor for all subjects integrated in the PFC. Therefore, we conclu-de that both imageries can be used to mentally train a motor task, and probably both sexes can be benefited.
Revista Brasileira de Cineantropometria e Desempenho Humano, 2013
Acute effect of motor imagery on basketball players' free throw performance and self-efficacy Efe... more Acute effect of motor imagery on basketball players' free throw performance and self-efficacy Efeito agudo da imagética no desempenho de lances livres e percepção de autoeficácia em atletas
Psychology and Neuroscience, 2014
The function of the prefrontal cortex (PFC) appears to be more activated in men than in women whe... more The function of the prefrontal cortex (PFC) appears to be more activated in men than in women when it is conditioned to emotional situations via external stimuli. The aim of the present study was to investigate the effects of different music genres on PFC oxygenation according to gender. Eighteen healthy volunteers (10 males and 8 females), aged 20-28 years (mean: 22.25 ± 2.34 years), participated in the study. They remained in silence, and hemoglobin levels in a linear scattering were recorded (O 2 Hb [oxyhemoglobin] and HHb [deoxyhemoglobin]). When this procedure was finished, music was played for 1.5 min. The results showed that different genres of music might change cortical oxygenation in several ways, and such modulation may be related to gender. We conclude that music modulated cortical oxygenation in the PFC in both the right and left hemispheres, and differences in cortical oxygenation were highly related to gender. Furthermore, preferred and motivational songs can be considered the most important for increasing blood flow in the listening process.
Revista Brasileira de Atividade Física & Saúde, 2012
do Esporte (CAME) propõe algumas recomendações para a prática de atividade física na tentativa de... more do Esporte (CAME) propõe algumas recomendações para a prática de atividade física na tentativa de aprimorar a saúde ou prevenir problemas crônicos degenerativos ao ser humano, dessa forma algumas estratégias ergogênicas podem auxiliar essa prática, entre elas o uso da música, capaz de possibilitar um melhor desempenho e menor percepção de esforço. Sendo assim, o objetivo deste estudo foi investigar o efeito da música em variáveis psicofisiológicas de adultos durante a prática de atividade física prescrita segundo as recomendações do CAME/AAC, (2007). Participaram deste estudo 10 voluntários saudáveis do sexo masculino (22,3 ± 1,8 anos, 175,0 ± 5,5 cm e 74,8 ± 11,0 Kg) que realizaram duas sessões experimentais de 30 minutos em ciclossimulador com intensidade correspondente a 60% da frequência cardíaca de reserva (FC Limiar de Treino), sobre duas condições: Música (M) e Controle (C). Foram avaliadas as variáveis: potência média (W MED), variabilidade da frequência cardíaca (VFC), percepção subjetiva de esforço (PSE) e o estado de humor (EH) dos participantes. Para as variáveis: PSE, W MED , VFC foi usado o teste de análise de variância (ANOVA-two-way) para medidas repetidas, seguido do post-hoc de Bonferroni e para a variável EH foi usado o teste de Wilcoxon. O nível de significância estatística adotada nas análises foi de 5%. Nenhuma diferença estatisticamente significante foi encontrada para as variáveis W MED , VFC, PSE e EH dos participantes entre as condições M e C (P > 0,05). Conclui-se que a música não foi capaz de influenciar as medidas psicofisiológicas em esforço submáximo.
Applied Mathematics, 2014
Frequency domain analyses in electromyographic (EMG) signals are frequently applied to assess mus... more Frequency domain analyses in electromyographic (EMG) signals are frequently applied to assess muscle fatigue and similar variables. Moreover, Fourier-based approaches are typically used for investigating these procedures. Nonetheless, Fourier analysis assumes the signal as stationary which is unlikely during dynamic contractions. As an alternative method, wavelet-based treatments do not assume this pattern and may be considered as more appropriate for joint time-frequency domain analysis. Based on the previous statements, the purpose of the present study was to compare the application of Short-Time Fourier Transform (STFT) and Continuous Wavelet Transform (CWT) to assess muscle fatigue in dynamic exercise of a 1-km of cycling (time-trial condition). The results of this study indicated that CWT and STFT analyses have provided similar fatigue estimates (slope) (p > 0.05). However, CWT application represents lesser dispersion (<variance) in comparison with STFT (p < 0.05) for vastus medialis (189.9 ± 82.1 for STFT vs 148.6 ± 60.2 for CWT) and vastus lateralis (151.6 ± 49.6 for STFT vs 103.5 ± 27.9 for CWT). In conclusion, despite the EMG signal did not change (p > 0.05) according to different methods, it is important to note that these responses seem to show greater values for CWT compared to STFT for 2 superficial muscles. Thereby, we are capable of considering CWT as a reliable and useful method to take into consideration when non-stationary or oscillating exercise models are evaluated.
A B S T R A C T The efficacy of motor imagery (MI) practice to facilitate muscle stretching remai... more A B S T R A C T The efficacy of motor imagery (MI) practice to facilitate muscle stretching remains controversial and the underlying neurophysiological mechanisms unexplored. We evaluated the effects of MI practice during a sit-and-reach task. Healthy participants were randomly assigned to a MI practice (n = 15) or Control (n = 15) group and completed 2 blocks of 5 sit-and-reach trials. During the first block (B1), participants performed 5 maximal stretching trials of 10s. During the second block (B2), trials were divided into two consecutive parts: i) reproducing the maximum performance of B1 (10s, B2 part 1), and ii) attempting to outperform the maximum performance of B1 (10s, B2 part 2). Participants performed kinesthetic MI of hamstring stretching during B2 trials in the MI practice group. We recorded electromyography from the hamstring and rectus femoris of the dominant leg. We also processed skin conductance as an index of sympathetic activity. We measured greater performance improvements from B1 to B2 part 2 in the MI practice group compared to Control (p < 0.05). Participants in the MI practice group exhibited reduced hamstring activation during both B2 part 1 (p < 0.001) and B2 part 2 (p < 0.001) compared to Control. Skin conductance revealed higher sympathetic activation during B2 part 2 compared to both B1 and B2 part 1 in the two groups. Thus, performing MI during actual movement is likely to improve stretching performance through reduced muscle activation. Such improvement may be grounded in a cortical gain over spinal reflexes.
There is compelling evidence that motor imagery contributes to improved motor performance , and r... more There is compelling evidence that motor imagery contributes to improved motor performance , and recent work showed that dynamic motor imagery (dMI) might provide additional benefits by comparison with traditional MI practice. However, the efficacy of motor imagery in different states of physical fatigue remains largely unknown, especially as imagery accuracy may be hampered by the physical fatigue states elicited by training. We investigated the effect of static motor imagery (sMI) and dMI on free-throw accuracy in 10 high-level basketball athletes, both in a non-fatigued state (Experiment 1) and immediately after an incre-mental running test completed until exhaustion (20m shuttle run-test–Experiment 2). We collected perceived exhaustion and heart rate to quantify the subjective experience of fatigue and energy expenditure. We found that dMI brought better shooting performance than sMI, except when athletes were physically exhausted. These findings shed light on the conditions eliciting optimal use of sMI and dMI. In particular, considering that the current physical state affects body representation, performing dMI under fatigue may result in mis-matches between actual and predicted body states.
—The effect of motor imagery (MI) practice on iso-metric force development is well-documented. Ho... more —The effect of motor imagery (MI) practice on iso-metric force development is well-documented. However, whether practicing MI during the rest periods of physical training improves the forthcoming performance remains unexplored. We involved 18 athletes in a counterbalanced design including three physical training sessions scheduled over five consecutive days. Training involved 10 maximal isometric contractions against a force plate, with the elbow at 90°. During two sessions, we integrated MI practice (focus-ing on either muscle activation or relaxation) during the inter-trial rest periods. We measured muscle performance from force plate and electromyograms of the biceps brachii and anterior deltoideus. We continuously monitored electro-dermal activity (EDA) to control sympathetic nervous system activity. MI of muscle activation resulted in higher isometric force as compared to both MI of muscle relaxation and passive recovery (respectively +2.1% and +3.5%). MI practice of muscle relaxation also outperformed the control condition (+1.9%). Increased activation of the biceps brachii was recorded under both MI practice conditions compared to control. Biceps brachii activation was similar between the two MI practice conditions, but electromyography revealed a marginal trend toward greater activation of the anterior deltoideus during MI practice of muscle activation. EDA and self-reports indicated that these effects were independent from physiological arousal and motivation. These results might account for priming effects of MI practice yielding to higher muscle activation and force performance. Present findings may be of interest for applications in sports training and neurologic rehabilitation. Ó 2015 Published by Elsevier Ltd. on behalf of IBRO.
Applied Mathematics, 2014
Frequency domain analyses in electromyographic (EMG) signals are frequently applied to assess mus... more Frequency domain analyses in electromyographic (EMG) signals are frequently applied to assess muscle fatigue and similar variables. Moreover, Fourier-based approaches are typically used for investigating these procedures. Nonetheless, Fourier analysis assumes the signal as stationary which is unlikely during dynamic contractions. As an alternative method, wavelet-based treatments do not assume this pattern and may be considered as more appropriate for joint time-frequency domain analysis. Based on the previous statements, the purpose of the present study was to compare the application of Short-Time Fourier Transform (STFT) and Continuous Wavelet Transform (CWT) to assess muscle fatigue in dynamic exercise of a 1-km of cycling (time-trial condition). The results of this study indicated that CWT and STFT analyses have provided similar fatigue estimates (slope) (p > 0.05). However, CWT application represents lesser dispersion (<variance) in comparison with STFT (p < 0.05) for vastus medialis (189.9 ± 82.1 for STFT vs 148.6 ± 60.2 for CWT) and vastus lateralis (151.6 ± 49.6 for STFT vs 103.5 ± 27.9 for CWT). In conclusion, despite the EMG signal did not change (p > 0.05) according to different methods, it is important to note that these responses seem to show greater values for CWT compared to STFT for 2 superficial muscles. Thereby, we are capable of considering CWT as a reliable and useful method to take into consideration when non-stationary or oscillating exercise models are evaluated.
Influence of Different Strategies of Treatment Muscle Contraction and Relaxation Phases on EMG Signal Processing and Analysis During Cyclic Exercise
Computational Intelligence in Electromyography Analysis - A Perspective on Current Applications and Future Challenges, 2012
For a long time we work with muscular activity, trying to answer questions related to fatigue, mu... more For a long time we work with muscular activity, trying to answer questions related to fatigue, muscle activity and other issues related to neuromuscular system. In this way we started to use the electromyography (EMG) as a tool to achieve better results in our studies, since it appeared to us as a truthful method to access the muscle activity inside a lot of perspectives we had been working with. In this chapter we will try to bring some research results that we found on the GEPESINE laboratory in the last couple of years about regarding the EMG analysis. Firstly there are relevant issues that arise during the use of EMG as a tool in others works.
Influence of Different Strategies of Treatment Muscle Contraction and Relaxation Phases on EMG Signal Processing and Analysis During Cyclic Exercise
Computational Intelligence in Electromyography Analysis - A Perspective on Current Applications and Future Challenges, 2012
For a long time we work with muscular activity, trying to answer questions related to fatigue, mu... more For a long time we work with muscular activity, trying to answer questions related to fatigue, muscle activity and other issues related to neuromuscular system. In this way we started to use the electromyography (EMG) as a tool to achieve better results in our studies, since it appeared to us as a truthful method to access the muscle activity inside a lot of perspectives we had been working with. In this chapter we will try to bring some research results that we found on the GEPESINE laboratory in the last couple of years about regarding the EMG analysis. Firstly there are relevant issues that arise during the use of EMG as a tool in others works.
Music: a psychophysiological aid to physical exercise and sport
Archivos de Medicina del Deporte
The use of music has been identified as a potential ergogenic aid that helps to improve performan... more The use of music has been identified as a potential ergogenic aid that helps to improve performance in exercise. Music has been classified as a psychological ergogenic aid and has attracted interest mainly for its effects found in studies with a focus on performance during exercise, pre-task and post-task. In this context, the objective of this study was to review the literature about the main effects of music on performance and their possible mechanisms, covering new perspectives about the theme. The method consisted of search, selection and stratification of the original articles of major databases (Medline, Sport Discuss, Scopus, Web of Science and Scielo) using the descriptors music, exercise, performance and fatigue. We considered all models and types of exercise and music. These articles suggest that the use of music as an ergogenic aid could be efficient to improve performance; decrease rate perceived of exertion and is capable to bring better feelings to exercise, according ...
Effects of caffeine on performance and mood of cyclists
Revista da Educação Física/UEM
This study analyzed the effects of caffeine ingestion on physical performance and mood state of c... more This study analyzed the effects of caffeine ingestion on physical performance and mood state of cyclists in a 1km time trial test. Ten male cyclists performed randomly a 1km time-trial test under two experimental conditions: Caffeine (CAF - 6 mg.kg-1) and placebo (PL) 60 min before the test. During the test were obtained the total time and the mood using the Brunel questionnaire (BRUMS). For comparisons of total time and mood states it was applied the paired Student's t-test and Wilcoxon test, respectively. No significant differences were found in the total time to complete tests and in the mood states between CAF and PL conditions (P>0.05). The results suggested that caffeine does not improve performance or change the mood of cyclists in a 1km time trial test.
Revista da Educação Física/UEM
O objetivo do estudo foi analisar os efeitos da ingestão de cafeína sobre o desempenho físico e e... more O objetivo do estudo foi analisar os efeitos da ingestão de cafeína sobre o desempenho físico e estado de humor de ciclistas em teste contrarrelógio de 1 km. Dez ciclistas do sexo masculino realizaram aleatoriamente um teste contrarrelógio de 1 km em duas condições experimentais: ingestão de cafeína (CAF - 6 mg.kg-1) e placebo (PL) 60 min antes do teste. Durante os testes foram obtidas as medidas de tempo total e estado de humor pelo questionário de Brunel (BRUMS). Para comparações dos parâmetros tempo total e estado de humor, foi utilizado o teste t de Student pareado e teste Wilcoxon, respectivamente. Nenhuma diferença estatisticamente significante foi encontrada no tempo total e no estado de humor nas condições CAF e PL (P>0,05). Os resultados sugerem que a cafeína não melhora o desempenho físico e nem altera o estado de humor dos atletas em um teste contrarrelógio de 1 km.
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Papers by Thiago F D Kanthack