Efeitos da ingestão proteica superior à recomendação da RDA na função muscular de mulheres pós-menopausadas praticantes de exercício de força

Abstract

Introduction: Postmenopausal period leads to changes in women body composition, especially in regard to the reduction of muscle mass, strength and functional capacity. Such changes are totally related to functional impairment, since there is a greater risk of falls, weakness and loss of independence, negatively impacting women's quality of life. Objective: To evaluate the effect of protein intake recommended by Recommended Dietary Allowance (RDA) with new consumption proposals and the impact on strength and functional capacity of postmenopausal women after exercise protocol. Material and methods: A blind, randomized, parallel and prospective study was performed. Postmenopausal women were divided into two groups: RDA group (NP), which received a diet plan containing ~0.8g protein·kg−1·d−1 or New Proposals Group (HP), which received ~1.2g protein·kg−1·d−1. Resistance training protocol was performed 3 times/week, with intensity of 10-12 maximal repetitions. Strength (maximum repetition - 1-RM and handgrip strength) and functional capacity (Short Physical Performance Battery - SPPB, 6-minute walk test, 400-meter walk test, 10-meter walk test and Timed Up and Go test - TUG) were evaluated before and after the intervention. The diet was evaluated by nine 24-hour food recalls. Dietary intervention and resistance training protocol lasted 10 weeks. Results: HP group presented higher protein intake (1.18±0.3 vs 0.87±0.2g protein·kg−1·d−1, p = 0.008) than NP group, respectively, during the study. After intervention, only HP increased bench press RM, leg extension RM and right/left handgrip, however, no differences were found by analyzing the delta (Δ) of these variables when compared to NP group (ΔBench press RM: 2.75±3.01 vs 1.09±2.25 kg, p = 0.153; ΔLeg extension RM: 6.75±12.46 vs 9.45±7.03 kg, p = 0.533; ΔRight handgrip: 1.66±3.20 vs 1.90±1.64 kg, p = 0.823 and ΔLeft handgrip: 1.83±2.62 vs 2.81±2.56 kg, p = 0.373), NP and HP group respectively. For the other tests, no differences between groups and/or moments were observed. Conclusion: A protein intake according to new proposals did not improve strength and functional capacity of postmenopausal women when compared to RDA recommendation after resistance training protocol.