The ACTN3 R577X variant in sprint and strength performance

Abstract

[Purpose] The aim of this study is to examine the association between the distribution of ACTN3 genotypes and alleles in power, speed, and strength-oriented athletics. [Methods] ACTN3 genotyping was carried out for a total of 975 Korean participants: top-level sprinters (n=58), top-level strength athletes (n=63), and healthy controls (n=854). [Results] Genetic associations were evaluated by chi-squire test or Fisher’s exact test. In the power-oriented group composed of sprinters and strength athletes, the frequency of the XX genotype was significantly underrepresented (11.6%) in comparison to its representation in the control group (11.6% versus 19.1%, P<0.05). When the power-oriented group was divided into strength-oriented and speed-oriented groups, no significant difference in the ACTN3 XX genotype was found between the strength-oriented athletes and the controls (15.9% versus 19.1%, P<0.262). Only the speed-oriented athletes showed significant differences in the frequency distributions of the ACTN3 XX genotype (6.9% versus 19.1%, P<0.05) from that of the controls. [Conclusion] The ACTN3 genotype seems to mainly affect sports performance and especially speed.