6. Human Muscle Protein Metabolism in Relation to Exercise and Aging: Potential Therapeutic Applications

  1. Valerie Askanas MD, PhD and
  2. W. King Engel MD
  1. Micah J. Drummond PhD1 and
  2. Blake B. Rasmussen PhD2

Published Online: 19 DEC 2011

DOI: 10.1002/9781444398311.ch6

Muscle Aging, Inclusion-Body Myositis and Myopathies

Muscle Aging, Inclusion-Body Myositis and Myopathies

How to Cite

Drummond, M. J. and Rasmussen, B. B. (2012) Human Muscle Protein Metabolism in Relation to Exercise and Aging: Potential Therapeutic Applications, in Muscle Aging, Inclusion-Body Myositis and Myopathies (eds V. Askanas and W. K. Engel), Wiley-Blackwell, Oxford, UK. doi: 10.1002/9781444398311.ch6

Editor Information

  1. Departments of Neurology and Pathology, University of Southern California Neuromuscular Center, University of Southern California Keck School of Medicine, Good Samaritan Hospital, Los Angeles, CA, USA

Author Information

  1. 1

    Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA

  2. 2

    Department of Nutrition & Metabolism, Division of Rehabilitation Sciences, Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX, USA

Publication History

  1. Published Online: 19 DEC 2011
  2. Published Print: 27 JAN 2012

ISBN Information

Print ISBN: 9781405196468

Online ISBN: 9781444398311

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Keywords:

  • blood-flow restriction;
  • human;
  • leucine;
  • mTORC1;
  • muscle wasting;
  • resistance exercise;
  • translation initiation

Summary

Age-related muscle loss (sarcopenia) can result in muscle weakness, injuries, loss of mobility, and eventual loss of independence. Data reported within the last decade strongly support that a key contributor to muscle loss is the reduced muscle-protein-synthesis response following anabolic stimuli such as resistance exercise and nutrient ingestion, especially mixed meals which raise insulin levels. Although many cellular and molecular pathways likely participate in the gradual muscle loss that accompanies aging, we suggest that the mammalian target of rapamycin (mTORC1) cellular signaling pathway is integral in stimulating translation initiation and elongation and, furthermore, muscle protein synthesis. This chapter thoroughly reviews the current literature in humans and identifies cellular mechanisms of age-related anabolic resistance following exercise and nutritional intake. We conclude the chapter with possible therapeutic strategies to restore or even overcome sarcopenia, such as traditional resistance exercise training, combining resistance exercise with postexercise essential amino acid or protein ingestion, and implementing blood-flow restriction exercise.