RESUMO
In this paper, we present a quantitative assessment of muscle fatigue using surface electromyography (sEMG), a widely recognized method that is conducted through various analytical approaches, including analysis of spectral and time-frequency distributions. Existing research in this field has demonstrated considerable variability in the computational methods used. Although some studies highlight the efficacy of wavelet analysis in dynamic motion, few offer a comprehensive method for determining fatigue and applying it to specific movements. Previous research has focused primarily on discerning differences based on sport type or gender, with a notable absence of studies that presented results for quantifying fatigue during exercise with rowing ergometers. Developing on our previous work, where we introduced a method for determining muscle fatigue through wavelet analysis, considering biomechanical aspects of limb position changes, this current article serves as a continuation. Our study refines the research approach for a selected group, focusing on fatigue determination using the previously established method. The results obtained confirm the effectiveness of DWT analysis in assessing muscle fatigue, as evidenced by the achievement of negative values of the regression coefficients of Median Frequency (MDF) during exercises performed to maximal fatigue. Furthermore, it has been confirmed that the homogeneity of the group and, in the case of the examined group, the results previously achieved or lower limb strength do not have an impact on the results. Finally, we discuss the main limitations of our study and outline the subsequent steps of our investigation, providing valuable information for future investigations in this field.
RESUMO
Abstract Few studies about food consumption of athletes have assessed the quality of their food choices, and the factors that influence these choices. The aim of this study was to assess the diet of team sports athletes through a revised version of the Healthy Eating Index (HEI-R) in order to identify their nutritional knowledge and the stage of intention to change eating behavior (SICEB) and to identify possible association with demographic and anthropometric variables. Seventy-two athletes (35 men) were evaluated for the following variables: body mass, height, Body Mass Index (BMI), body fat percentage (BF%), nutritional knowledge (questionnaire), food intake (24-hour recall), diet quality (HEI-R) and SICEB (transtheoretical model). For statistical analysis, the Student t test and the Pearson correlation coefficient were used. None of the athletes presented diet classified as "healthy" and 45.7% (men) and 51.4% (women) had "inadequate" diets. Low consumption of fruits, vegetables, whole grains, milk and dairy products was observed. The HEI-R "meats, legumes and eggs" component received the best scores. Pre-contemplation (25.0%) and action (23.6%) stages were the most frequent in the group. The mean percentage of correct answers in the nutritional knowledge questionnaire was 55.7% (men) and 57.3% (women). No association was found between HEI-R and variables age, BMI, BF%, SICEB, nutritional knowledge score and energy intake. This group presents inadequate dietary intake. The lack of association between study variables indicates the need to investigate other factors that influence athlete's feeding behavior.
Resumo Poucos estudos sobre o consumo alimentar de atletas avaliam a qualidade dos alimentos selecionados e os fatores que interferem nessas escolhas. Objetivou-se avaliar a dieta de atletas de esportes coletivos por meio do Índice de Qualidade da Dieta - Revisado (IQD-R), identificar seu conhecimento nutricional, estágio de intenção de mudança de comportamento alimentar (EIMCA) e identificar possíveis associações com variáveis demográficas e de antropometria. Foram avaliadas as seguintes variáveis em 72 atletas (35 homens): massa corporal (MC), estatura, IMC, percentual de gordura (%G), conhecimento nutricional (questionário), consumo alimentar (recordatório de 24-horas), qualidade da dieta (IQD-R) e EIMCA (modelo transteórico). Para a análise estatística empregou-se o teste t de Student e coeficiente de correlação de Pearson. Nenhum atleta apresentou dieta classificada como "saudável" e 45,7% (homens) e 51,4% (mulheres) apresentaram dieta "inadequada". Há baixo consumo de frutas, hortaliças, cereais integrais e leite e derivados. O componente do IQD-R "carnes, leguminosas e ovos" recebeu a melhor pontuação. Os estágios pré-contemplação (25,0%) e ação (23,6%) foram os mais frequentes. O percentual médio de acertos dos atletas no questionário de conhecimentos nutricionais foi 56,5%. Não foi observada associação entre IQD-R e as variáveis: idade, IMC, %G, EIMCA, escore de conhecimento nutricional e consumo energético. O grupo apresenta inadequação do consumo alimentar. A falta de associação entre as variáveis estudadas indica a necessidade de investigação de outros fatores que influenciam o comportamento alimentar de atletas.