Exercise and Protein Effects on Strength and Function with Weight Loss in Older Women. Issue 1 (January 2021)

• Record Type: Journal Article
• Authors: EVANS, ELLEN M.; STRAIGHT, CHAD R.; REED, RACHELLE A.; BERG, ALISON C.; ROWE, DAVID A.; JOHNSON, MARY ANN
• Is Part Of: Medicine and science in sports and exercise. Volume 53:Issue 1(2021)
• Publication Date: 2021-01
• Subjects: MULTICOMPONENT EXERCISE TRAINING -- PHYSICAL FUNCTION -- DIETARY PROTEIN; Sports medicine -- Periodicals; Exercise -- Physiological aspects -- Periodicals; Exercise -- Health aspects -- Periodicals; 612.044
• DOI: 10.1249/MSS.0000000000002429
• Languages: English
• ISSNs: 0195-9131

Abstract

ABSTRACT: Obesity negatively affects lower extremity physical function (LEPF) in older adults. Exercise and a higher protein diet are both known to positively and independently affect body composition, muscle strength, and LEPF during weight loss; however, their potential interactive effects have not been well characterized in older women. Purpose: The aim of this study was to determine the relative efficacy of a higher protein diet with or without exercise to improve body composition, muscle strength, and LEPF in older inactive overweight/obese women after weight loss. Methods: Postmenopausal women (body mass index = 31.1 ± 5.1 kg·m −2, 69.2 ± 3.6 yr) completed a 6-month weight loss program after randomization to three groups ( n = 72 randomized; 15% dropout): 1) higher protein diet (PRO, ~30% energy from protein; n = 20), 2) PRO plus exercise (PRO + EX; n = 19), or 3) a conventional protein control diet plus EX (CON + EX, ~18% energy from protein; n = 22). EX was supervised, multicomponent (aerobic, muscle strengthening, balance, and flexibility), and three sessions per week. Body composition was measured via dual-energy x-ray absorptiometry, leg strength by isokinetic dynamometry, and LEPF via 6-min walk, 8-ft up and go, and 30-s chair stand tests. Results: Changes in weight (−7.5 ± 4.1 kg; −9.2% ± 4.8%), fat mass, and leg lean mass did not differ among groups (all P > 0.50). Despite weight loss, muscle strength improved in the exercise groups (PRO + EX and CON + EX) but it declined in the PRO group ( P = 0.008). For all LEPF measures, the PRO group had attenuated improvements compared with both PRO + EX and CON + EX (all P < 0.01). Conclusion: Exercise during weight loss is critical to preserve strength and enhance LEPF; however, a higher protein diet does not appear to influence body composition, muscle strength, or LEPF changes when combined with multicomponent exercise.