Definition of gain muscle and nitrogen retention of bodybuilders: Ingestion energy versus protein.
palavras-chave: treinamento com pesos, ingestão energética, ingestão protéica, balanço nitrogenado, ingestão glicídica.
Keywords: resistance exercises, energy intake, protein intake, nitrogen balance, carbohydrate intake.
resumo
Objetivo: estabelecer a relação entre o consumo energético e de proteínas com o peso, massa muscular e adiposa do corpo e balanço nitrogenado. Metodologia: Foram estudados 42 homens saudáveis (18-35 anos), com dois anos de treinamento com pesos e sem uso de ergogênicos. Após a avaliação do consumo alimentar, antropometria (peso, altura, circunferências e dobras cutâneas) e cálculos do índice de massa corporal (IMC kg/m2), adiposidade corporal, massa muscular e balanço nitrogenado (BN), todos os indivíduos receberam dieta com 1,5g de proteína/kg de peso/dia durante as duas primeiras semanas, seguida de 2,5g de proteína/kg de peso/dia, por mais duas semanas. As dietas foram associadas ao protocolo de treinamento com pesos (6 dias/semana). Resultados: As análises de variância (ANOVA) e correlação de Pearson mostraram que com o aumento da ingestão protéica de 1,8 para 2,2g/kg/dia houve positiva e significante relação com BN (r=0,61), mas sem aumento significante da massa muscular. A ingestão energética total teve boa correlação com BN (r=0,69), peso corporal (r=0,59), massa muscular (r=0,41) e gordura corporal (r=0,34). Pela correção da ingestão energética, com a protéica, os valores „d 30kcal/g de proteína resultaram em maiores ganhos da massa muscular e do BN, sem aumento da gordura corporal. Entre os substratos energéticos a ingestão de carboidratos teve correlação forte e positiva e a de gordura negativa, com o BN e a massa muscular. Conclusão: desta forma, conclui-se que a composição corporal alterada pelo treinamento com pesos pode ser modulada pelos componentes energéticos da dieta em magnitude igual ou mesmo superior à ingestão protéica.
abstract
purpose: establishing the relationship between the dietary energy-yielding nutrients with the body weight, muscle and fat mass and nitrogen balance. methodology: we studied 42 clinically healthy volunteered men (18-35 yrs) on at least two-year body building training. After a baseline (M0) assessment of food intake (24h questionnaire recall), anthropometry (body weight, height, arms and trunk circumferences and skinfolds) and calculations of BMI (kg/m2), body fatness (Siri equations), muscle mass (Martin equation) and nitrogen balance, they all have adjusted the protein intake to approximately 1.5 kg/day offered during the first two weeks followed by 2.5g/kg/day given sequentially to the other two weeks. Both diets were fed along with a 6 day/wk resistance training protocol and preceded (M1) and succeeded (M2) by the assessments described for M0. Results: The analysis of variance (ANOVA) and correlation of Pearson showed that by increasing protein intake from 1.8 to 2.2 g/kg/day there was a positive and significant relationship with nitrogen balance (r=0.61) without significant increase on muscle mass. Total energy intake correlated well to nitrogen balance (r=0.69) body weight (r=0.59) muscle mass (r=0.41) and body fat (r=0.34). By correcting the energy intake by the protein, the values ≥ 30kcal/g protein gave greater gain of both muscle mass and nitrogen balance without fat gaining. Among the dietary energy-yielding substrates the carbohydrate had the strongest positive and the fat the negative relationship with nitrogen balance, and muscle mass. Conclusion: thus it was concluded that energy compounds of the diet can modulated the body composition changed by resistance training.