Comparable Rates of Integrated Myofibrillar Protein Synthesis Between Endurance-Trained Master Athletes and Untrained Older Individuals

Frontiers in Physiology

Sara Y. Oikawa¹  Stuart M. Phillips¹  Carolyn Greig²  Leigh Breen²  Benoit Smeuninx⁴  James McKendry⁴  Brandon J. Shad⁴  Gareth Wallis⁴ 

[1] Department of Kinesiology, McMaster University, Hamilton, ON, Canada;MRC-Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom;NIHR Birmingham Biomedical Research Centre, Birmingham, United Kingdom;School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom;

关键词: muscle;    anabolism;    master athlete;    resistance exercise;    sarcopenia;   

DOI  :  10.3389/fphys.2019.01084

来源: DOAJ

【 摘 要 】

BackgroundAn impaired muscle anabolic response to exercise and protein nutrition is thought to underpin age-related muscle loss, which may be exacerbated by aspects of biological aging that may not be present in older individuals who have undertaken long-term high-level exercise training, or master athletes (MA). The aim of this study was to compare rested-state and exercise-induced rates of integrated myofibrillar protein synthesis (iMyoPS) and intracellular signaling in endurance trained MA and healthy age-matched untrained individuals (Older Controls).MethodsIn a parallel study design, iMyoPS rates were determined over 48 h in the rested-state and following a bout of unaccustomed resistance exercise (RE) in OC (n = 8 males; 73.5 ± 3.3 years) and endurance-trained MA (n = 7 males; 68.9 ± 5.7 years). Intramuscular anabolic signaling was also determined. During the iMyoPS measurement period, physical activity was monitored via accelerometry and dietary intake was controlled.ResultsAnthropometrics, habitual activity, and dietary intake were similar between groups. There was no difference in rested-state rates of iMyoPS between OC (1.47 ± 0.06%⋅day–1) and MA (1.46 ± 0.08%⋅day–1). RE significantly increased iMyoPS above rest in both OC (1.60 ± 0.08%⋅day–1, P < 0.01) and MA (1.61 ± 0.08%⋅day–1, P < 0.01), with no difference between groups. AktThr308 phosphorylation increased at 1 h post-RE in OC (P < 0.05), but not MA. No other between-group differences in intramuscular signaling were apparent at any time-point.ConclusionWhile our sample size is limited, these data suggest that rested-state and RE-induced iMyoPS are indistinguishable between MA and OC. Importantly, the OC retain a capacity for RE-induced stimulation of skeletal muscle remodeling.

【 授权许可】

Unknown