Effect of Protein Consumption and Resistance Training on Body Composition, Muscular Strength and Functional Capacity in the Elderly

The increase in life expectancy of the world population is associated with a higher incidence of diseases, leading to functional incapacity and dependence in old age. Aging is usually accompanied by progressive loss of muscle mass, muscular strength and functional capacity, possibly exacerbated by inactivity and low protein and energy consumption of elderly individuals. However, the response to strength training, as well as the daily recommendation of protein and other factors related to sarcopenia in this population seem not to be well understood. Objective: To evaluate the effect of protein intake and resistance training on body composition, muscle strength and functional capacity in the elderly. METHODS: A randomized placebo-controlled clinical trial will be conducted with 38 elderly people, ≥ 60 years old, sedentary, and body mass index between 22 and 30 kg / m2. All those who agree to participate will be randomized into two groups (intervention or placebo) and will undergo an initial assessment consisting of food consumption analysis through the application of the three-day food record, assessment of muscle thickness of the thigh and arm by muscle ultrasonography, evaluation of body composition by dual energy X-ray absorptiometry (DEXA), dynamic maximal strength (1RM) test of knee extension and elbow flexion, peak torque test of knee extension, functional capacity tests and quality of life questionnaire (SF-36). The elderly will participate in resistance training for 12 weeks, two session per week. The intervention group will be supplemented with whey protein isolate (2x / day - 20g for breakfast and 20g for dinner) and the placebo group will receive maltodextrin (2x / day - 20g for breakfast and 20g for dinner). All outcomes will be assessed before and after the 12-week resistance training period.