Protein supplementation before and after resistance training in older men
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We determined the effects of protein supplementation immediately before (PRO-B) and after (PRO-A) resistance training (RT; 12 weeks) in older men (59–76 years), and whether this reduces deficits in muscle mass and strength compared to younger men (18–40 years). Older men were randomized to PRO-B (0.3 g/kg protein before RT + placebo after RT, n=9), PRO-A (placebo before + protein after RT, n=10), or PLA (placebo before and after RT, n=10). Lean tissue mass, muscle thickness of the elbow, knee, and ankle flexors and extensors, and leg and bench press strength were measured before and after RT and compared to databases of younger subjects (n=22–60). Myofibrillar protein degradation (3-methylhistidine) and bone resorption (cross-linked N-telopeptides) were also measured before and after RT. Lean tissue mass, muscle thickness (except ankle dorsi flexors), and strength increased with training (P<0.05), with little difference between groups. There were no changes in 3-methylhistidine or cross-linked N-telopeptides. Before RT, all measures were lower in the older compared to younger groups (P<0.05), except for elbow extensor muscle thickness. Following training, muscle thickness of the elbow flexors and ankle dorsi flexors and leg press strength were no longer different than the young, and elbow extensor muscle thickness was greater in the old men (P<0.05). Supplementation with protein before or after training has no effect on muscle mass and strength in older men. RT was sufficient to overcome deficits in muscle size of the elbow flexors and ankle dorsi flexors and leg press strength in older compared to younger men.
KeywordsAge Muscle Strength Catabolism Bone
This study was supported through a research grant from Experimental and Applied Sciences, Golden, CO, USA, and by the Natural Sciences and Engineering Research Council of Canada. Funding for the weight training equipment was provided by the Saskatchewan Health Research Foundation. The authors would like to thank Dr Bernhard Juurlink, Department of Anatomy and Cell Biology at the University of Saskatchewan for the use of his lab and materials.
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