{{Genotype
|rsid=1815739
|allele1=T
|allele2=T
|magnitude=2.3
|summary=Impaired muscle performance. Likely endurance athlete.
}}
{{PMID|18043716}} This is under-represented in elite strength and sprint athletes, consistent with previous reports of impaired muscle performance. However this is more common in endurance athletes. This SNP makes fast-twitch muscle fibers completely unable to produce alpha-actinin-3.