Correlation Among Muscle Mass, Strength And Cross Sectional Muscle Area According To Carbohydrate And Protein Supplementation

Abstract

Many people participating in resistance training such as weigh lifting, weigh training and body building have used a variety of high calorie nutritional supplements in effort to gain body mass, muscle mass and muscular strengh. The aim of this study was to investigate the relationship among muscle mass (Mm), strengh and cross sectional muscle area (CSA) according to carbohydrate (NP) and protein (HP) intake in young men undergoing 8 weeks of resistance training. The sample was constituted by 16 men (BMI: 23.6 ± 2.51 kg/m2) from 23–37 y of age (x: 28.5 ± 1.8 y). Subjects were randomly assigned to 1 of 2 groups, HP (n=8; age= 30.2±1.9 y; height= 176 ± 4.4; body mass= 24.2 ± 1,9 kg/m2): the supplemention of protein altogether with protein intake from the diet should consisted of 4g/kg−1/d−1 (x: 136.9 g) and NP (n=8; age= 27.5±1.8 y; height= 172.9 ± 6.7; body mass= 23.8 ± 2,7 kg/m2): consisted of subjects administered a carbohydrate supplement that was isocaloric with the HP supplement (x: 233g, 812.5 kcal). The volunteers were selected from the Physical Education of the Military Police of Sao Paulo, SP - Brazil. Muscle mass (Mm) and body fat percentage (% fat) were determined through skinfold and circunferences measurements, it was used the protocols developed by Durning & Womwersley, 1974, and by Siri (1961). The CSA was determined by computed tomography. Strengh was determined by 1 RM test. The training volume and intensity were defined as 5 sets of 8 repetitions using 80% of 1 RM for the exercises: biceps: 2 exercises, triceps: 2 exercises. The statistical analyses used was Pearson-correlation coefficient (r). The significance level adopted was p < 0,05. The mean values of pretest and post-test intervention for protein, carbohydrate, calorie intake, fat free mass and cross sectional area were: P= 133.5 ± 32.3g to 296.8 ± 31.3g (4g/kg−1/d−1); C= 362.1 ± 48.6g to 337.8 ± 48.3g, Kcal= 3108 ± 491.4 to 3709 ± 215.9 kcal; Mm= 61.2 ± 6.2 kg to 61.5 ± 3.3 kg, and CSA= 46.5 ± 11.4 cm2 to 51.7 ± 12.5 cm2 for the HP group, and P= 127.8 ± 20g to 129.9 ± 14.4g (4g/kg−1/d−1); C= 418.7 ± 81.7g to 580.7 ± 72.3g, Kcal= 3193 ± 493.6 to 3767 ± 492.7 kcal; Mm= 58.3 ± 4.4 kg to 61.4 ± 3.0 kg, and CSA= 48.1 ± 9 cm2 to 54.6 ± 11.7 cm2 for the NP group. The NP group presented significant association among carbohydrate (%) intake and CSA (r: 0.9, P=0.001), Mm and CSA (r: 0.8, P=0.001), and between strengh triceps and Mm (r: 0.8, P=0.001) These data indicated that high carbohydrate intake is effective in increasing strengh, Mm and CSA when combined with resistance training.