Carbohydrate mouth rinse improves performance of mentally fatigued cyclists despite null effects on psychological responses.

Mental fatigue reduces exercise performance through an impaired psychological response such as increased perceived exertion. Carbohydrate (CHO) mouth rinses improve exercise performance and perceived exertion likely due to an improved activation in cerebral reward areas, then we investigated if the CHO mouth rinse-improved exercise performance in mentally fatigued individuals was associated with ameliorated reward-related psychological responses. We hypothesised that CHO mouth rinse would be beneficial for mentally fatigued cyclists mainly in high-metabolic disturbance intensities. After familiarization and baseline sessions, well trained cyclists (n = 20) performed a maximal incremental test (MIT) after mental fatigue induction. They completed the MIT either without mouth rinse (MF) or rinsing their mouth with CHO (MF+CHO) or placebo (FM+PLA) solutions at every 25 % of the MIT. Psychological responses such as ratings of perceived exertion (RPE), affective valence, emotional arousal, and motivation were assessed throughout the MIT, while performance was assessed as peak power output and time of exercise. Mental fatigue reduced MIT performance (P < 0.05), but CHO mouth rinse was effective to counteract this deleterious mental fatigue effect (P < 0.05). However, we found null effects of CHO mouth rinses in psychological responses above the VT2 (P > 0.05) such as RPE, affective valence, emotional arousal, and motivation. Correlational analysis showed a significant, but moderate negative correlation between motivation and time of exercise above the VT2 when participants used CHO mouth rinse. In conclusion, the ergogenic CHO mouth rinse effects on MIT performance of mentally fatigued cyclists were irrespective of ameliorated psychological responses to exercise.

No Evidence of Postactivation Performance Enhancement on Endurance Exercises: A Comprehensive Systematic Review and Meta-analysis.

PURPOSE: Narrative reviews have suggested that postactivation induced by warm-up routines is effective to increase endurance exercise performance in real-world scenarios. However, systematic reviews with meta-analysis rather than narrative ones are required to provide an up-to-date summary of the evidence and provide directions for practical decisions. Therefore, we systematically reviewed peer-reviewed and gray literature to determine the certainty of evidence and the relative effects of postactivation performance enhancement (PAPE) in endurance exercises. METHODS: The effects of PAPE on endurance performance were meta-analyzed as a standardized mean difference (SMD) from control conditions within a random-effects model considering polled data and subgroups (PAPE strategies, endurance test modalities, and V̇O 2max -based endurance level). RESULTS: Eligible studies ( n = 35) showed a high risk of bias due to methodological flaws in randomization and blinding procedures. A meta-analysis including 57 comparisons (432 participants) revealed a significant but very small PAPE effect on endurance performance ( Z = 2.49, SMD = 0.15-very small, 95% confidence interval = 0.03 to 0.28) due to exceptional effect sizes reported by two studies (SMD of 2.85 and 2.14). We also observed that neither PAPE strategies nor endurance test modalities or V̇O 2max -based endurance levels influenced the PAPE effects on endurance performance. Meta-regression showed that PAPE effects were correlated neither with the time interval between conditioning routines and endurance exercise nor with endurance exercise duration. We found a very low certainty of evidence that PAPE potentiates endurance performance. CONCLUSIONS: Based on the analyses of bias and certainty of evidence, we found no support to recommend PAPE strategies to improve endurance exercise performance. Significant but very small PAPE effects on endurance performance were due to two exceptional effect sizes.

Measurement of physical activity and sedentary behavior in adolescents by accelerometer: a cross-sectional study / Atividade física e comportamento sedentário em adolescentes medidas por acelerômetro: um estudo transversal

The objective of this study was to analyze the level of physical activity and sedentary behavior (SB) in students from Minas Gerais, Brazil. It is a cross-sectional study with 153 participants of both sexes and had to be between 10 and 12 old. We carried out measurements of socioeconomic and anthropometric variables. Also, physical activity and sedentary behavior were measured using an accelerometer (MiniMitter, Actiheart®). The accelerometer was fixed on the chest and the participants should remain with it for three days (Thursday, Friday, and Saturday). We categorized the data as SB - < 1.6 METs (< 0.39 kcal.kg-1.15min-1); light physical activity - 1.6 to 2.9 METs (0.42 to 0.76 kcal.kg-1.15min-1). In the study, both sexes showed a low time of moderate and vigorous (~ 0.85 hours/day) activities. Higher times were recorded for light activity (~ 2.6 hours/day) and SB (~ 12.5 hours/day) in both sexes. Also, boys spent greater time on a vigorous physical activity and lower time of SB in the three evaluated days (~ 1.3 hours/day boys vs ~ 0.4 hours/day girls) (p = 0.001; np2= 0.42). However, the physical activity behavior was similar during weekdays and weekends (p = 0.14; np2= 0.078). We conclude that boys are more engaged than girls in physical activities in public schools of Minas Gerais, Brazil. However, SB is similar between them

O objetivo do estudo foi analisar o nível de atividade física e comportamento sedentário (CS) em escolares. Trata-se de um estudo transversal com 153 escolares de 10 a 12 anos de ambos os sexos, de escolas públi-cas de São João Nepomuceno do estado de Minas Gerais, Brasil. Foi realizada a mensuração de variáveis socioeconômicas e antropométricas e a utilização de acelerômetro para medir o nível atividade de física. O acelerômetro foi fixado no peito dos participantes por um período de 3 dias (quinta, sexta e sábado). A partir disso os dados do acelerômetro foram definidos em CS - < 1,6 METs (< 0,39 kcal.kg-1.15min-1); atividade física leve ­ 1,6 a 2,9 METs (0,42 a 0,76 kcal.kg-1.15min-1). No estudo, ambos os sexos apresentaram baixo tempo de atividades moderadas a vigorosas (~ 0,85 horas/dia). O principal achado indicou um elevado tempo em atividade leves (~ 2,6 horas/dia) e CS (~ 12,5 horas/dia) em ambos os sexos. De acordo com o sexo, os meninos apresentaram mais tempo envolvidos em atividades físicas moderada a vigorosas e baixo CS nos três dias avaliados (~ 1,3 horas/dia meninos e ~ 0,4 horas/dia meninas) (p = 0.001; np2= 0.42). Além disso, o comportamento da atividade física foi semelhante nos dias úteis e finais de semana (p = 0.14; np2= 0.078). Concluímos que para os três dias avaliados, meninos apresentam maior tempo de envolvimento em atividades moderada a vigorosa, porém ambos os sexos com alto CS

Percepção da qualidade de vida em atletas de atletismo e natação paralímpica / Perception of quality of life in athletes of athletics and swimming paralympic

Resumo O objetivo do presente estudo foi avaliar a percepção da qualidade de vida (QV) dos atletas paralímpicos das modalidades de atletismo e natação. Tratou-se de um estudo descritivo e de corte transversal com 32 paratletas, sendo 22 de atletismo e 10 de natação. Para avaliação da QV foi utilizado o questionário de avaliação abreviado da qualidade de vida da Organização Mundial da Saúde. Para análise dos dados foi utilizado o teste de Shapiro-Wilk; como os dados apresentaram distribuição não paramétrica, foi adotada a apresentação descritiva em mediana (Md) e intervalo interquartílico (Q1; Q3). Para comparar a QV em função do gênero e do patrocínio, foi utilizado o teste de "U" de Mann-Whitney, e para comparar a QV entre o nível de escolaridade, foi utilizado o teste de Kruskal-Wallis. Observou-se entre os domínios de QV que o domínio meio ambiente obteve o menor índice e o domínio social obteve o maior índice entre os paratletas pesquisados. Em relação aos subgrupos mais prejudicados os menores valores encontrados foram entre os paratletas com níveis de escolaridades fundamental I e nível superior, que apresentaram diferenças nos domínios ambientais e de QV geral, fundamental I com ensino médio, apenas na QV geral e fundamental II com ensino superior, apenas no domínio ambiental. Não foram constatadas diferenças significativas na percepção da QV entre os paratletas com e sem patrocínio, e entre as modalidades atletismo e natação. Conclui-se que os atletas paralímpicos que possuem menor nível de escolaridade apresentaram-se como os grupos com menores percepções de QV.

Abstract The objective of the present study was to evaluate the perception of the quality of life (QoL) of Paralympic athletes of athletics and swimming. It was a descriptive and cross-sectional study with 32 Paralympic athlete. To evaluate the QoL, the questionnaire of abbreviated quality of life evaluation of the World Health Organization was used. For the analysis of the data the Shapiro-Wilk test was used; because the data presented non-parametric distribution, the descriptive presentation was adopted in median (Md) and interquartile range (Q1; Q3). To compare QoL according to gender and sponsorship, the Mann-Whitney "U" test was used, and the Kruskal-Wallis test was used to compare the QoL between the level of schooling. There was a lower perception of QoL in the environmental domain and a greater perception in the social domain among the parathletes surveyed. In relation to the most impaired subgroups, the lowest values ​​were found among paratrans with primary and higher levels of schooling presented differences in environmental domains and general QoL, fundamental I with secondary education, only in general and fundamental QoL II with higher education, only in the environmental domain. There were no significant differences in the perception of QoL between Paralympic athlete with and without sponsorship, and between athletics and swimming modalities. It is concluded that Paralympic athletes who have lower level of schooling presented themselves as the groups with lower perceptions of QoL.

Can disordered eating behaviors reduce maximum oxygen consumption in road cyclists? / Comportamentos de risco para os transtornos alimentares pode reduzir o consumo máximo de oxigênio em ciclistas de estrada?

Abstract The aim of this study was to compare the maximum oxygen consumption (VO2max) between road cyclists with and without risk for eating disorders. The sample was composed of 43 cyclists aged 18-25 years, participants of the road cycling championship of the State of Pernambuco. VO2max was measured by a computerized metabolic analyzer during an incremental test in cycleergometer. The initial test load was 50 W, with increments of 25 W every minute until volitional exhaustion or inability to maintain the current load. To evaluate disordered eating behaviors (DEB), the Eating Attitudes Test was used (EAT-26). Univariate analysis of covariance (ANCOVA) was used to compare the VO2max between cyclists with (EAT-26 ≥ 21) and without (EAT-26 < 21) risk for eating disorders. The findings showed statistically significant VO2max difference between cyclists with and without risk to eating disorders (F (2,41)=28.44; p=0.01), indicating moderate effect size (d = 0.6). It was concluded that DEB was related to cyclists with lower VO2max.

Resumo O objetivo da pesquisa foi comparar o consumo máximo de oxigênio (VO2máx) entre ciclistas de estrada com e sem risco para o desencadeamento de transtornos alimentares. A amostra foi composta por 43 ciclistas com idade entre 18 e 25 anos, participantes do campeonato pernambucano de ciclismo de estrada. O VO2máx foi mensurado por um analisador metabólico computadorizado no decorrer de um teste incremental realizado em cicloergômetro. A carga inicial do teste foi 50 W, com incrementos de 25 W a cada minuto até atingir a exaustão voluntária ou impossibilidade de manter a carga atual. Para avaliar os comportamentos de risco para os transtornos alimentares (CRTA) foi utilizado o Eating Attitudes Test (EAT-26). Conduziu-se a análise univariada de covariância (ANCOVA) para comparar o VO2máx entre ciclistas com (EAT-26≥21) e sem riscos (EAT-26<21) para os transtornos alimentares. Os achados revelaram diferença estatisticamente significante do VO2máx entre ciclistas com e sem risco para os transtornos alimentares (F(2,41)=28,44; p=0,01), indicando moderado tamanho do efeito (d=0,6). Concluiu-se que os CRTA estiveram relacionados aos ciclistas com menor VO2máx.

Effect of tapering on anaerobic power and capacity of tae-kwon-do athletes / Efeito de um período de polimento na potência e capacidade anaeróbia de atletas de tae-kwon-do

Abstract The aim of the study was to analyze the effect of a tapering period on anaerobic power and capacity of tae-kwon-do athletes. Thirty-one male tae-kwon-do participants of the Brazilian Championship were selected in a non-probabilistic way. Subjects were randomly divided into two groups, namely: experimental group (EG, n = 15) and control group (CG, n = 17). Both groups followed the same training protocol up to the tapering stage. CG was submitted to training loads contained in the last two weeks of the macrocycle. Only EG was submitted to tapering. Tapering had 2 weeks duration, adopting the linear tapering method. Taekwondo Anaerobic Test was performed by athletes before the start of the season, which was named as pre-intervention, and the last week of each mesocycle [Prep I, Prep II and Tapering (only EG)]. Group vs. time effect interaction (p < 0.01) was identified for alactic anaerobic power, with an increase only in EG in tapering (p = 0.01). A significant group vs. time interaction (p <0.01) was revealed to fatigue index, improved anaerobic capacity being checked in EG only after the tapering period (p = 0.01). It was concluded that two weeks of linear type tapering optimized the anaerobic power and capacity of male tae-kwon-do athletes.

Resumo O objetivo do estudo foi analisar o efeito de um período de polimento sobre a potência e capacidade anaeróbia de atletas de tae-kwon-do. Trinta e um atletas de tae-kwon-do do sexo masculino participantes do campeonato brasileiro de tae-kwon-do foram selecionados de forma não probabilística. Os atletas foram separados aleatoriamente em dois grupos, a saber: experimental (GE, n = 15) e controle (GC, n = 17). Ambos os grupos seguiram o mesmo treinamento até a fase do polimento. O GC manteve as cargas de treinamento constantes nas últimas duas semanas do macrociclo. Somente o GE realizou o polimento. O polimento teve duração de 2 semanas, adotando-se o método de polimento linear. O Taekwondo Anaerobic Test foi realizado pelos atletas antes do início da temporada, o que foi denominado como pre-intervenção, e na última semana de cada mesociclo [Preparatório I, Preparatório II e Polimento (somente para o GE)]. Foi identificado efeito de interação grupo vs. tempo (p < 0,01) para a potência anaeróbia alática, com aumento apenas no GE na fase do polimento (p = 0,01). Uma interação significante grupo vs. tempo (p < 0,01) foi revelada para o índice de fadiga, com melhoria da capacidade anaeróbia sendo verificada no GE somente após a fase de polimento (p = 0,01). Concluiu-se que duas semanas de polimento do tipo linear otimizou a potência e capacidade anaeróbia de atletas de tae-kwon-do do sexo masculino.

Disordered eating behaviors in young volleyball players: can be the coach's leadership style an intervenient factor? / Comportamentos de risco para os transtornos alimentares em jovens atletas de voleibol: o estilo de liderança do treinador é um fator interveniente?

Abstract The aim of this study was to analyze the influence of coach’s leadership style on eating disorders (ED) in female volleyball athletes. This is a prospective study with 73 participants of sub-17 state of Pernambuco Championship. The Eating Attitudes Test was applied to evaluate ED. The perception of the coach’s leadership style was evaluated with Leader Sport Scale subscales. Triceps and subscapular skinfolds were measured to estimate body fat percentage. The findings showed no influence of “Training-Instruction” on ED (F(3, 70)=45.02; R2=0.12; p=0.34). The “Social Support” subscale showed statically significant influence on ED (F(4, 69)=59.77; R2=-0.16; p=0.02). However, the results indicated no statically significant relationship of “Reforce” subscale with ED (F(5, 68)=52.40; R2=0.13; p=0.17). The “Democratic” subscale so showed no influence on ED F(6, 67)=49.08; R2=0.10; p=0.21). Finally, the “Autocratic” subscale showed influence on ED (F(7, 66)=67.23; R2=0.18; p=0.01). We concluded that the coach’s leadership style (social support and autocratic) influenced the adoption of DEB in young female volleyball athletes.

Resumo O objetivo da investigação foi analisar a influência do estilo de liderança do treinador sobre os comportamentos de risco para os transtornos alimentares (CRTA) em atletas de voleibol do sexo feminino. Trata-se de uma investigação com delineamento prospectivo (follow-up de 3 meses) desenvolvida com 73 atletas participantes do campeonato Pernambucano da categoria sub-17. Para avaliar os CRTA foi aplicado o Eating Attitudes Test. A fim de se avaliar a percepção do estilo de liderança do treinador, foram utilizadas as subescalas da versão percepção-atleta da Escala de Liderança no Desporto. Foram aferidas as dobras cutâneas triciptal e subescapular para a estimativa do percentual de gordura corporal. Os achados não revelaram influência da subescala “Treino-Instrução” sobre os CRTA (F(3, 70)=45,02; R2=0,12; p=0,34). A subescala “Suporte Social” demonstrou influência estatisticamente significante nos CRTA (F(4, 69)=59,77; R2=-0,16; p=0,02). Todavia, os resultados não indicaram relação estatisticamente significante da subescala “Reforço” com os CRTA (F(5, 68)=52,40; R2=0,13; p=0,17). Do mesmo modo, a subescala “Democrático” também não demonstrou influência sobre os CRTA (F(6, 67)=49,08; R2=0,10; p=0,21). Por fim, a subescala “Autrocrático” apontou influência sobre os CRTA (F(7, 66)=67,23; R2=0,18; p=0,01). Concluiu-se que o estilo de liderança do treinador (suporte social e autocrático) influenciou na adoção de CRTA em jovens atletas de voleibol do sexo feminino.

Effect of 10% weight loss on simulated taekwondo match performance: a randomized trial.

The objective of the present study was to analyze the effect of 10% body mass reduction on simulated taekwondo match performance. Thirty-one male taekwondo athletes were randomly distributed in two groups: weight loss group (n= 15) - athletes in this group reduced 5% body mass per week during two successive weeks, totaling 10% body mass reduction; control group (n= 16) - athletes in this group kept their body mass constant during the 2-week period. Twenty-four hours before and after this period, athletes performed a simulated 3-round taekwondo match (6 min). Athletes wore body protectors to validate the scores during the match according to the official taekwondo rules. Match was filmed and actions were categorized using the Game Performance Assessment Instrument. There was a group and time interaction (P< 0.001) for body mass, with decrease only for the weight loss group (P= 0.001). A group and time interaction was also observed for the taekwondo match performance (P< 0.001), with performance increase being found only for the control group (P= 0.01). Thus, the 10% weight loss was not a good strategy to improve taekwondo skills' performance.