Luciano Sales Prado

Maximal lactate steady state is altered in the heat.

The aim of this study was to compare the maximal lactate steady state (MLSS) and ventilatory threshold (VT) under different environments (TEMP: 22°C; and HOT: 40°C; 50% RH). 8 male subjects (age 23.9±2.4 years, body mass 75.9±7.3 kg and VO2(max) 47.8±4.9 mL·kg(-1)·min(-1)) performed a series of tests to determine the peak workload (W(peak)), VT and MLSS on a cycle ergometer. W(peak) was higher in the TEMP as compared to the HOT condition (225±9 W vs. 195±8 W, respectively; p<0.05). The workload at MLSS was higher at 22°C (180±11 W) than 40°C (148±11 W; p<0.05), as well as VT at 22°C (156±9 W) was higher than 40°C (128±6 W). Likewise, the blood lactate concentration at MLSS was higher at 22°C (5.60±0.26 mM) than 40°C (4.22±0.48 mM; p<0.05). The mean of heart rate (HR) was not statistically different between TEMP (168±3 bpm) and HOT (173±3 bpm) at MLSS, despite being different at trials between the 25(th) and the 30(th) min of exercise. The HR at VT was significantly higher in HOT (153±4 bpm) as compared to the TEMP (145±2 bpm). Our results suggest that environmental conditions may influence the determination of MLSS and VT. Moreover, VT was appropriate for estimation of the workload at MLSS in the HOT.

Selected anthropometric variables and aerobic fitness as predictors of cardiovascular disease risk in children.

The aim of this study was to assess the suitability of body mass index, waist circumference, waist-to-height ratio and aerobic fitness as predictors of cardiovascular risk factor clustering in children. A cross-sectional study was conducted with 290 school boys and girls from 6 to 10 years old, randomly selected. Blood was collected after a 12-hour fasting period. Blood pressure, waist circumference (WC), height and weight were evaluated according to international standards. Aerobic fitness (AF) was assessed by the 20-metre shuttle-run test. Clustering was considered when three of these factors were present: high systolic or diastolic blood pressure, high low-density lipoprotein (LDL) cholesterol, high triglycerides, high plasma glucose, high insulin concentrations and low high-density lipoprotein (HDL) cholesterol. A ROC curve identified the cut-off points of body mass index (BMI), WC, waist-to-height ratio (WHtR) and AF as predictors of risk factor clustering. BMI, WC and WHR resulted in significant areas under the ROC curves, which was not observed for AF. The anthropometric variables were good predictors of cardiovascular risk factor clustering in both sexes, whereas aerobic fitness should not be used to identify cardiovascular risk factor clustering in these children.

Cargas elevadas de treinamento alteram funções cognitivas em jogadores de futebol

INTRODUCTION: In the performance sports, high training loads are necessary for biological adaptations to occur leading to the improvement of fitness and sports performance.OBJECTIVE: To investigate the behavior of the psychological and physiological variables, indicators of possible states of stress and recovery in soccer players throughout the sports season, and the possibility of using these as markers of the conditions of athletes trainability to prevent decreased performance and overtraining.METHODS: The study included 14 soccer players (18.4±0.6 years, 9.64±1.61% with fat and VO2max 49.46 ± 2.88 ml/kg/min) of a junior class of a team of the first division of Brazil. The perception of stress and recovery, the heart rate variability (HRV) at rest, analyzed in the time and frequency domain, and simple reaction time were monitored through the questionnaire RESTQ-Sport. We carried out three collections of data, a control (C), another after four weeks of intense training (T1), and finally after four weeks of light training (T2) performed after T1.RESULTS: No significant difference was found in any of the scales of RESTQ-Sport and HRV at the three collections. The simple reaction time showed a significant increase (p=0.047) in T1 compared to C.CONCLUSION: The results indicate that the reaction time was the only variable sensitive to changes in the training study and could be considered a good indicator of trainability of athletes.INTRODUCCION: En el deporte de rendimiento, las altas cargas de entrenamiento son necesarias para que ocurran adaptaciones biologicas que lleven a la mejora de la forma fisica y del desempeno deportivo.OBJETIVO: Investigar el comportamiento de variables psicologicas y fisiologicas, posibles indicadores de los estados de estres y recuperacion, en jugadores de futbol a lo largo de la temporada deportiva, y la posibilidad del uso de los mismos como marcadores de los estados de entrenabilidad de los atletas para prevenir caidas del desempeno y overtraining.METODOS: Participaron en este estudio 14 jugadores de futbol (18,4 ± 0,6 anos, 9,64 ± 1,61 % con gordura y VO2max49,46 ± 2,88 ml/kg/min) de la categoria junior de un equipo de primera division de Brasil. Fueron monitoreadas la percepcion de estres y la recuperacion por medio del cuestionario RESTQ-Sport, la variabilidad de frecuencia cardiaca (VFC) de reposo, analizada en el dominio del tiempo y de la frecuencia, y el tiempo de reaccion simple. Se efectuaron tres colectas de datos, un control (C), otra despues de cuatro semanas de entrenamientos intensos (T1), y finalmente despues de cuatro semanas de entrenamientos leves (T2) realizados despues de T1.RESULTADOS: No fue encontrada diferencia significativa en ninguna de las escalas de RESTQ-Sport y en VFC en los tres momentos de colecta. El tiempo de reaccion simple presento un aumento significativo (p = 0,047) en T1 en relacion a C.CONCLUSION: Los resultados indican que el tiempo de reaccion fue la unica variable sensible a las alteraciones del entrenamiento estudiado, pudiendo ser considerado un buen indicador de la entrenabilidad de los atletas.

The effects of menstrual cycle phase on the incidence of plateau at V˙O2max and associated cardiorespiratory dynamics

The purpose of this study was to examine the effect of menstrual cycle phase on maximal oxygen uptake ( V˙O2max ) and associated cardiodynamic responses. A total of 16 active females volunteered of which n = 10 formed the non‐oral contraceptive pill group (n‐OCP), displaying a regular menstrual cycle of 28·4 ± 2·2 days (age 20·6 ± 1·6 years, height 169·9 ± 6·4 cm, mass 68·7 ± 7·9 kg) and n = 6 formed the oral contraceptive pill group (OCP) (monophasic pill) (age 21·7 years ± 2·16, height 168·1 cm ± 6·8 cm, mass 61·6 ± 6·8 kg). Each completed four incremental exercise tests for determination of V˙O2max , cardiac output, stroke volume and heart rate. Each test was completed according to the phases of the menstrual cycle as determined through salivary analysis of 17‐β oestrodiol and progesterone. Non‐significant differences were observed for V˙O2max across phases and between groups (P>0·05) with additional non‐significant differences for Q˙max , HRmax and SVmax between groups. For ∆ V˙O2 during the final 60 s of the V˙O2max trial, significant differences were observed between OCP and n‐OCP (P<0·05) with OCP showing zero V˙O2 plateaus in three pseudo‐phases. Significant difference observed for a‐vO2dif n‐OCP between premenstruation and menstruation at 30–100% V˙O2max (P<0·05). Data suggest that the V˙O2 ‐plateau is effected by monophasic oral contraceptive pill, furthermore these data imply that V˙O2max test outcome is independent of menstrual cycle phase but caution should be applied when evaluating maximal oxygen uptake in females who are administered a monophasic oral contraceptive pill.

Effects of Precooling on 30-km Cycling Performance and Pacing in Hot and Temperate Environments

This study examined the effects of precooling on performance and pacing during 30-km cycling exercise in hot and temperate environments. 8 trained male cyclists performed 4 trials involving either cooling (PRECTEMP and PRECHOT) or no-cooling interventions (TEMP and HOT) prior to a 30-km self-paced cycling exercise in either a hot (35°C, 68% relative humidity) or temperate environment (24°C, 68% relative humidity). Exercise time was longer in HOT (60.62±3.47 min) than in TEMP (58.28±3.30 min; P<0.001), and precooling attenuated this thermal strain performance impairment (PRECHOT 58.28±3.30 min; P=0.048), but it was still impaired compared with TEMP (P=0.02). Exercise performance in PRECTEMP (54.58±4.35 min) was no different from TEMP. Initial power output was sustained until the end of the exercise in both TEMP and PRECTEMP, but was reduced from the 12th km until the end of the trial in HOT (P<0.05). This reduction was delayed by precooling because power output was reduced only after the 20th km during PRECHOT (P<0.05). Heart rate was similar in all conditions throughout almost the entire exercise, suggesting the maintenance of similar relative intensities. In conclusion, precooling was effective in attenuating, but not completely reversing thermal strain performance impairment and offered no ergogenic effect in the temperate environment.

FADIGA MENTAL NÃO ALTERA A RECUPERAÇÃO DA FREQUÊNCIA CARDÍACA, MAS AFETA O DESEMPENHO DE JOGADORES DE HANDEBOL

ABSTRACT Introduction: This study involved an analysis of the impact of mental fatigue on heart rate recovery (HRR), subjective measures of fatigue and intermittent running performance in handball players. Objective: This study was aimed at (1) examining the effects of an induced state of mental fatigue on the aerobic performance of handball players, as measured by the Yo-Yo IR1 test, and (2) exploring possible changes in heart rate regulation through HRR analysis. Methods: Twelve handball players (age: 17.50 ± 3.63 years; 5 ± 2.2 years of practice) undertook a Yo-Yo IR1 test on two occasions, separated by an interval of at least 72 hours. The Yo-Yo IR1 test was preceded by a 30-min treatment, consisting of the Stroop Color-Word Test, to induce mental fatigue. Participants in the control condition watched an emotionally neutral video. Results: Higher ratings of mental fatigue and mental effort following the Stroop Test were observed for the experimental group. No differences in motivation were observed between conditions. Moreover, the induction of mental fatigue impaired running performance and led to a higher RPE during the Yo-Yo IR1 test. Notwithstanding, no changes in HRR or blood lactate levels were observed across conditions. Conclusion: Altogether, these results suggest that mental fatigue impairs intermittent running performance, without affecting HRR values. Level of Evidence III; Case-Control study.

Influence of Autonomic Control on the Specific Intermittent Performance of Judo Athletes

Abstract Judo is a high-intensity intermittent combat sport which causes cardiac adaptations both morphologically and related to the autonomic nervous system (ANS). Therefore, this study aims to verify the correlation between heart rate variability (HRV) at rest with performance in the Special Judo Fitness Test (SJFT) and whether groups with different RR values at rest show different performance in the SJFT and during post-test recovery. Sixteen judo athletes with 7.2 ± 3.9 years of training experience participated in the study. Before and after the SJFT execution HRV and lactate measurements were conducted. For HRV analysis, we used the mean interval RR, the standard deviation of the RR interval (SDNN), the root mean square of successive differences in RR intervals (RMSSD), the low frequency (LF) and high frequency (HF) in normalized and absolute units. The sample was split into two groups (low RR and high RR) to verify if this variable could differentiate between specific performance. For the SDNN, a significant and moderate correlation (r = 0.53) was found with the total number of throws and throws in the series A (r = 0.56) and B (r = 0.54) and for the RMSSD a correlation with throws during series B (r = 0.59) in the SJFT. However, the groups did not differ in performance and recovery. Therefore, HRV is related to intermittent judo performance; however, it cannot differentiate between judokas at different levels of performance.

Capacidade de estabilização pélvica em nadadores de diferentes estilos

INTRODUCCION: los estilos de nado con movimientos alternados o simultaneos de los miembros superiores pueden generar demandas diferentes sobre los musculos lumbopelvicos. La evaluacion de la alineacion pelvica en el plano transversal contribuye para la comprension de la influencia de esas diferentes demandas provenientes del nado sobre la estabilidad pelvica.OBJETIVOS: investigar el efecto del entrenamiento de estilos con brazadas alternadas o con brazadas simultaneas sobre la estabilizacion pelvica en el plano transversal.METODOS: fueron evaluados 113 nadadores, 63 practicantes de brazada alternada y 50 de brazada simultanea, a traves del test del puente con extension unilateral de la rodilla. la magnitud y asimetria de caida pelvica fueron cuantificadas por medio de programa de analisis de movimiento. El test de Mann-Whitney fue utilizado para verificar diferencias en la asimetria de caida pelvica entre atletas que practicaban brazada alternada y simultanea en cada repeticion del test. Fue realizado ANOVA con diseno mixto para investigar diferencias en la magnitud de caida pelvica entre repeticiones considerando la brazada practicada.RESULTADOS: La asimetria de caida pelvica no presento diferencia entre grupos en ninguna repeticion. La magnitud de caida pelvica fue mayor en la tercera repeticion 15,96 ± 7,18o que en la primera 15,13 ± 7,52o y segunda 15,16 ± 7,35o en todos los nadadores. Los practicantes de brazada alternada presentaron mayor magnitud de caida pelvica que los de brazada simultanea 16,46 ± 7,38o versus 14,13 ± 7,08o.CONCLUSION: el tipo de brazada practicada no influencia la asimetria de la alineacion pelvica en el plano transversal. Entretanto, la magnitud de caida pelvica fue mayor en la tercera repeticion y en practicantes de brazada alternada.

Cargas elevadas de entrenamiento alteran funciones cognitivas en jugadores de fútbol

INTRODUCTION: In the performance sports, high training loads are necessary for biological adaptations to occur leading to the improvement of fitness and sports performance.OBJECTIVE: To investigate the behavior of the psychological and physiological variables, indicators of possible states of stress and recovery in soccer players throughout the sports season, and the possibility of using these as markers of the conditions of athletes trainability to prevent decreased performance and overtraining.METHODS: The study included 14 soccer players (18.4±0.6 years, 9.64±1.61% with fat and VO2max 49.46 ± 2.88 ml/kg/min) of a junior class of a team of the first division of Brazil. The perception of stress and recovery, the heart rate variability (HRV) at rest, analyzed in the time and frequency domain, and simple reaction time were monitored through the questionnaire RESTQ-Sport. We carried out three collections of data, a control (C), another after four weeks of intense training (T1), and finally after four weeks of light training (T2) performed after T1.RESULTS: No significant difference was found in any of the scales of RESTQ-Sport and HRV at the three collections. The simple reaction time showed a significant increase (p=0.047) in T1 compared to C.CONCLUSION: The results indicate that the reaction time was the only variable sensitive to changes in the training study and could be considered a good indicator of trainability of athletes.INTRODUCCION: En el deporte de rendimiento, las altas cargas de entrenamiento son necesarias para que ocurran adaptaciones biologicas que lleven a la mejora de la forma fisica y del desempeno deportivo.OBJETIVO: Investigar el comportamiento de variables psicologicas y fisiologicas, posibles indicadores de los estados de estres y recuperacion, en jugadores de futbol a lo largo de la temporada deportiva, y la posibilidad del uso de los mismos como marcadores de los estados de entrenabilidad de los atletas para prevenir caidas del desempeno y overtraining.METODOS: Participaron en este estudio 14 jugadores de futbol (18,4 ± 0,6 anos, 9,64 ± 1,61 % con gordura y VO2max49,46 ± 2,88 ml/kg/min) de la categoria junior de un equipo de primera division de Brasil. Fueron monitoreadas la percepcion de estres y la recuperacion por medio del cuestionario RESTQ-Sport, la variabilidad de frecuencia cardiaca (VFC) de reposo, analizada en el dominio del tiempo y de la frecuencia, y el tiempo de reaccion simple. Se efectuaron tres colectas de datos, un control (C), otra despues de cuatro semanas de entrenamientos intensos (T1), y finalmente despues de cuatro semanas de entrenamientos leves (T2) realizados despues de T1.RESULTADOS: No fue encontrada diferencia significativa en ninguna de las escalas de RESTQ-Sport y en VFC en los tres momentos de colecta. El tiempo de reaccion simple presento un aumento significativo (p = 0,047) en T1 en relacion a C.CONCLUSION: Los resultados indican que el tiempo de reaccion fue la unica variable sensible a las alteraciones del entrenamiento estudiado, pudiendo ser considerado un buen indicador de la entrenabilidad de los atletas.

High loads of training affect cognitive functions in soccer players

INTRODUCTION: In the performance sports, high training loads are necessary for biological adaptations to occur leading to the improvement of fitness and sports performance.OBJECTIVE: To investigate the behavior of the psychological and physiological variables, indicators of possible states of stress and recovery in soccer players throughout the sports season, and the possibility of using these as markers of the conditions of athletes trainability to prevent decreased performance and overtraining.METHODS: The study included 14 soccer players (18.4±0.6 years, 9.64±1.61% with fat and VO2max 49.46 ± 2.88 ml/kg/min) of a junior class of a team of the first division of Brazil. The perception of stress and recovery, the heart rate variability (HRV) at rest, analyzed in the time and frequency domain, and simple reaction time were monitored through the questionnaire RESTQ-Sport. We carried out three collections of data, a control (C), another after four weeks of intense training (T1), and finally after four weeks of light training (T2) performed after T1.RESULTS: No significant difference was found in any of the scales of RESTQ-Sport and HRV at the three collections. The simple reaction time showed a significant increase (p=0.047) in T1 compared to C.CONCLUSION: The results indicate that the reaction time was the only variable sensitive to changes in the training study and could be considered a good indicator of trainability of athletes.INTRODUCCION: En el deporte de rendimiento, las altas cargas de entrenamiento son necesarias para que ocurran adaptaciones biologicas que lleven a la mejora de la forma fisica y del desempeno deportivo.OBJETIVO: Investigar el comportamiento de variables psicologicas y fisiologicas, posibles indicadores de los estados de estres y recuperacion, en jugadores de futbol a lo largo de la temporada deportiva, y la posibilidad del uso de los mismos como marcadores de los estados de entrenabilidad de los atletas para prevenir caidas del desempeno y overtraining.METODOS: Participaron en este estudio 14 jugadores de futbol (18,4 ± 0,6 anos, 9,64 ± 1,61 % con gordura y VO2max49,46 ± 2,88 ml/kg/min) de la categoria junior de un equipo de primera division de Brasil. Fueron monitoreadas la percepcion de estres y la recuperacion por medio del cuestionario RESTQ-Sport, la variabilidad de frecuencia cardiaca (VFC) de reposo, analizada en el dominio del tiempo y de la frecuencia, y el tiempo de reaccion simple. Se efectuaron tres colectas de datos, un control (C), otra despues de cuatro semanas de entrenamientos intensos (T1), y finalmente despues de cuatro semanas de entrenamientos leves (T2) realizados despues de T1.RESULTADOS: No fue encontrada diferencia significativa en ninguna de las escalas de RESTQ-Sport y en VFC en los tres momentos de colecta. El tiempo de reaccion simple presento un aumento significativo (p = 0,047) en T1 en relacion a C.CONCLUSION: Los resultados indican que el tiempo de reaccion fue la unica variable sensible a las alteraciones del entrenamiento estudiado, pudiendo ser considerado un buen indicador de la entrenabilidad de los atletas.