ACTN3

TraitSportsModerate evidenceBackground

Your muscle fiber type skews toward power or endurance.

ACTN3 influences fast-twitch muscle fibers. One common variant is more typical in sprinters and power athletes; another pattern shows up more in endurance athletes. Neither decides your fitness - training still dominates - but it is a fun read on how you are built.

Also known as: sprinter gene, alpha-actinin-3

Associated with

  • muscle
  • sprint
  • endurance
  • athlete
  • fitness

Educational only. Significant findings should be reviewed with a clinician.

Educational reference only — not a diagnosis. Discuss significant findings with a clinician.