EFFECT OF INCREASED DAILY INTAKE OF PROTEIN, COMBINED WITH A PROGRAM OF RESISTANCE EXERCISES, ON THE MUSCLE MASS AND PHYSICAL FUNCTION OF COMMUNITY-DWELLING ELDERLY WOMEN

Abstract

Background: In elderly women, significant loss of muscle mass due to declining levels of estrogen secretion is a health concern. Increasing the recommended dietary allowance of protein intake has been included as a general health guideline to prevent age-related sarcopenia. Objectives: To investigate effects of light-to-moderate resistance training combined with increased protein intake on the muscle mass, strength, and physical function of community-dwelling elderly women. Design: The 12-week training program combined weight-bearing and resistance band exercises, performed 3 times per week. Setting: Hyogo Prefecture, in either City K or Town H. Practical Intervention: Women were randomly allocated to three groups: exercise with protein intake adjusted to the recommended daily allowance (RDA) of 1.0–1.1 g/kg body weight/day (MP+EX group); exercise with protein intake adjusted above the RDA level at 1.2–1.3 g/kg body weight/day (HP+EX group); and a control group receiving classroom-based session on nutrition management, with protein intake adjusted to the RDA level (MP group). Measurements: Body weight and physical composition were measured by multi-frequency bioelectrical impedance analysis. Results: Exercise prevented decreases in muscle mass and strength and in performance of physical function tasks (p<0.05). Increasing dietary intake of protein above RDA level increased muscle mass (p<0.01), walking speed (p<0.01) and knee extensor strength (p<0.05). Conclusion: Adjusting protein intake to 1.2–1.3 g/kg body weight/day, in combination with light-to-moderate resistance training, can improve body composition and physical function in elderly women. The result of this study could be effective in lowering the incidence of age-related sarcopenia.