ACTN3: A genetic influence on muscle function and athletic performance

Exerc Sport Sci Rev. 2007 Jan;35(1):30-4. doi: 10.1097/JES.0b013e31802d8874.


A common variant of the ACTN3 gene, R577X, results in complete deficiency of the alpha-actinin-3 protein in the fast skeletal muscle fibers of more than a billion humans worldwide. We review the evidence that this genetic variant is strongly associated with elite athlete status and with normal variation in human muscle strength and sprinting speed.

Publication types

  • Review

MeSH terms

  • Actinin / genetics*
  • Humans
  • Musculoskeletal Physiological Phenomena*
  • Phenotype
  • Physical Endurance / genetics
  • Physical Fitness / physiology*
  • Sports*


  • ACTN3 protein, human
  • Actinin