Protein supplementation during resistance-type exercise training in the elderly.

Abstract

INTRODUCTION:

Resistance training has been well established as an effective treatment strategy to increase skeletal muscle mass and strength in the elderly. We assessed whether dietary protein supplementation can further augment the adaptive response to prolonged resistance-type exercise training in healthy elderly men and women.

METHODS:

Healthy elderly men (n = 31, 70 ± 1 yr) and women (n = 29, 70 ± 1 yr) were randomly assigned to a progressive, 24-wk resistance-type exercise training program with or without additional protein supplementation (15 g·d-1). Muscle hypertrophy was assessed on a whole-body Dual-energy X-ray absorptiometry (DXA), limb (computed tomography), and muscle fiber (biopsy) level. Strength was assessed regularly by 1-repetition maximum (RM) strength testing. Functional capacity was assessed with a sit-to-stand and handgrip test.

RESULTS:

One-RM strength increased by 45% ± 6% versus 40% ± 3% (women) and 41% ± 4% versus 44% ± 3% (men) in the placebo versus protein group, respectively (P < 0.001), with no differences between groups. Leg muscle mass (women, 4% ± 1% vs 3% ± 1%; men, 3% ± 1% vs 3% ± 1%) and quadriceps cross-sectional area (women, 9% ± 1% vs 9% ± 1%; men, 9% ± 1% vs 10% ± 1%) increased similarly in the placebo versus protein groups (P < 0.001). Type II muscle fiber size increased over time in both placebo and protein groups (25% ± 13% vs 30% ± 9% and 23% ± 12% vs 22% ± 10% in the women and men, respectively). Sit-to-stand improved by 18% ± 2% and 19% ± 2% in women and men, respectively (P < 0.001).

CONCLUSION:

Prolonged resistance-type exercise training increases skeletal muscle mass and strength, augments functional capacity, improves glycemia and lipidemia, and reduces blood pressure in healthy elderly men and women. Additional protein supplementation (15 g·d-1) does not further increase muscle mass, strength, and/or functional capacity.

• Authors: Marika Leenders, Lex B Verdijk, Letty Van der Hoeven, Janneau Van Kranenburg, Rachel Nilwik, Will K W H Wodzig, Joan M G Senden, Hans A Keizer, Luc J C Van Loon
• Journal: Medicine and science in sports and exercise (Med Sci Sports Exerc) Vol. 45 Issue 3 Pg. 542-52 (Mar 2013) ISSN: 1530-0315 [Electronic] United States
• PMID: 22968306 (Publication Type: Journal Article, Randomized Controlled Trial)

Chemical References

• Dietary Proteins
• Glycated Hemoglobin A
• Lipoproteins, LDL
• Cholesterol
• Creatinine
• Nitrogen

Topics

• Absorptiometry, Photon
• Adaptation, Physiological
• Aged
• Analysis of Variance
• Body Composition
• Cholesterol (blood)
• Creatinine (blood)
• Dietary Proteins (administration & dosage)
• Dietary Supplements
• Female
• Glycated Hemoglobin (metabolism)
• Hand Strength
• Humans
• Insulin Resistance
• Lipoproteins, LDL (blood)
• Male
• Muscle Fibers, Fast-Twitch (cytology)
• Muscle Strength
• Nitrogen (urine)
• Quadriceps Muscle (anatomy & histology, diagnostic imaging, physiology)
• Resistance Training
• Tomography, X-Ray Computed