Skeletal Muscle Hypertrophy Following Resistance Training Is Accompanied by a Fiber Type-Specific Increase in Satellite Cell Content in Elderly Men

J Gerontol A Biol Sci Med Sci. 2009 Mar;64(3):332-9. doi: 10.1093/gerona/gln050. Epub 2009 Feb 5.

Abstract

We determined muscle fiber type-specific hypertrophy and changes in satellite cell (SC) content following a 12-week resistance training program in 13 healthy, elderly men (72 +/- 2 years). Leg strength and body composition (dual-energy X-ray absorptiometry and computed tomography) were assessed, and muscle biopsy samples were collected. Leg strength increased 25%-30% after training (p < .001). Leg lean mass and quadriceps cross-sectional area increased 6%-9% (p < .001). At baseline, mean fiber area and SC content were smaller in the Type II versus Type I muscle fibers (p < .01). Following training, Type II muscle fiber area increased from 5,438 +/- 319 to 6,982 +/- 503 microm(2) (p < .01). Type II muscle fiber SC content increased from 0.048 +/- 0.003 to 0.084 +/- 0.008 SCs per fiber (p < .001). No changes were observed in the Type I muscle fibers. In older adults, skeletal muscle tissue is still capable of inducing SC proliferation and differentiation, resulting in Type II muscle fiber hypertrophy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Aged
  • Aging / metabolism
  • Aging / physiology*
  • Analysis of Variance
  • Anthropometry
  • Biopsy, Needle
  • Body Composition
  • Diet Records
  • Humans
  • Hypertrophy
  • Immunohistochemistry
  • Male
  • Muscle Fibers, Skeletal / metabolism
  • Muscle Fibers, Skeletal / pathology
  • Muscle Strength / physiology
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / pathology*
  • Probability
  • Reference Values
  • Resistance Training*
  • Sampling Studies
  • Satellite Cells, Skeletal Muscle / metabolism
  • Satellite Cells, Skeletal Muscle / pathology*
  • Tomography, X-Ray Computed