Impact of aerobic exercise training on age-related changes in insulin sensitivity and muscle oxidative capacity

Kevin R. Short, Janet L. Vittone, Maureen L. Bigelow, David N. Proctor, Robert A. Rizza, Jill M. Coenen-Schimke, K. Sreekumaran Nair

Research output: Contribution to journalArticle

433 Scopus citations

Abstract

Insulin resistance increases and muscle oxidative capacity decreases during aging, but lifestyle changes especially physical activity - may reverse these trends. Here we report the effect of a 16-week aerobic exercise program (n = 65) or control activity (n = 37) performed by men and women aged 21-87 years on insulin sensitivity and muscle mitochondria. Insulin sensitivity, measured by intravenous glucose tolerance test, decreased with age (r = -0.32) and was related to abdominal fat content (r = -0.65). Exercise increased peak oxygen uptake (VO2peak; 10%), activity of muscle mitochondrial enzymes (citrate synthase and cytochrome c oxidase, 45-76%) and mRNA levels of mitochondrial genes (COX4, ND4, both 66%) and genes involved in mitochondrial biogenesis (PGC-1α, 55%; NRF-1, 15%; TFAM, 85%). Exercise also increased muscle GLUT4 mRNA and protein (30-52%) and reduced abdominal fat (5%) and plasma triglycerides (25%). None of these changes were affected by age. In contrast, insulin sensitivity improved in younger people but not in middle-aged or older groups. Thus, the muscle mitochondrial response to 4 months of aerobic exercise training was similar in all age-groups, although the older people did not have an improvement in insulin sensitivity.

Original languageEnglish (US)
Pages (from-to)1888-1896
Number of pages9
JournalDiabetes
Volume52
Issue number8
DOIs
StatePublished - Aug 1 2003

ASJC Scopus subject areas

  • Internal Medicine
  • Endocrinology, Diabetes and Metabolism

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    Short, K. R., Vittone, J. L., Bigelow, M. L., Proctor, D. N., Rizza, R. A., Coenen-Schimke, J. M., & Nair, K. S. (2003). Impact of aerobic exercise training on age-related changes in insulin sensitivity and muscle oxidative capacity. Diabetes, 52(8), 1888-1896. https://doi.org/10.2337/diabetes.52.8.1888