Human Strength

[Polar]

Genotype influences muscle performance

"Elite endurance athletes commonly have mutations that result in the loss of the protein α-actinin-3, which is a major component of fast-twitch muscle fibers. Loss of α-actinin-3 is associated with reduced power, increased endurance capacity, and enhanced response to endurance training.

In this issue of the [i]Journal of Clinical Investigation, Kathryn North and colleagues at the Murdoch Children's Research Institute report that the loss of ?-actinin-3 in fast-twitch muscle fibers, results in compensation by ?-actinin-2. The presence of ?-actinin-2 in fast-twitch muscle contributed to reprogramming these muscles through increased calcineurin signaling.[/i]

This study provides insight into how mutations in the gene encoding ?-actinin-3 promote skeletal muscle adaptations that are advantageous to elite endurance athletes."

So, endurance runners naturally have microscopic aerobic muscular advantages to their muscles. Reply