Sarcopenia, age-associated involuntary loss of muscle and strength, can progress to clinically relevant functional decline. Resistance exercise attenuates muscle and strength loss but may not be feasible for some older adults. Aerobic exercise training (AET) improves cardiopulmonary health; however, effects on protein turnover, muscle mass, and strength are less clear. We aimed to determine whether AET improves basal myofibrillar protein synthesis (MPS) and capillarization, promoting hypertrophy and strength. We hypothesized that AET improves strength with increased MPS and capillarization. Older adults were randomized to non-exercise (NON; n = 11, 71.4 ± 4.18 years) or exercise (EX; n = 12, 73.7 ± 4.05 years). EX completed 24 weeks of AET (walking 3×/week, 45 minutes, 70% heart rate reserve); NON remained sedentary. A stable isotope tracer was infused. MPS and capillarization were analyzed from vastus lateralis muscle biopsies. Strength was measured via isokinetic dynamometry. Lean mass was determined with dual-energy X-ray absorptiometry. Basal MPS increased in EX (+50.7%, P = 0.01) along with capillary density (+66.4%, P = 0.03), peak oxygen consumption (+15.8%, P = 0.01), quadriceps strength (+15.1%, P = 0.01), and muscle quality (peak torque divided by leg lean mass, +15.5%, P = 0.01). Lean mass did not change (P > 0.05). AET increases muscle protein turnover and capillarization in older adults, improving muscle quality.
|Number of pages||11|
|Journal||Translational Sports Medicine|
|State||Published - Apr 2019|
Bibliographical noteFunding Information:
These results are without fabrication, falsification, or data manipulation. We gratefully recognize the contributions made by study coordinators: Jennifer Timmerman, Paula Skinkis, and Roxana Hirst, the nursing staff at UTMB ITS-Clinical Research Center, and by Samantha Lane, Kelli Faaitiiti, and Amanda Randolph. This work was supported by National Institutes of Health/National Institute on Aging (grant numbers R01AG030070, R01AG030070S1, R56AG051267, P30AG024832, UL1TR001439, and T32AG000270).
© 2019 The Authors. Translational Sports Medicine Published by John Wiley & Sons Ltd.
- protein turnover
- walking exercise
ASJC Scopus subject areas
- Orthopedics and Sports Medicine