ACTN3 Genotype in Professional Endurance Cyclists

• DOI: 10.1055/s-2006-923862
• Publication Date: 2006-11-08T16:20:22Z
• Authors: A. Lucia; F. Gómez-Gallego; C. Santiago; F. Bandrés; C. Earnest; M. Rabadán; J. Alonso; J. Hoyos; A. Córdova; G. Villa; C. Foster
• Keywords: Sprint; Endurance Training

The Z-disk protein α-actinin-3 is only expressed in type II muscle fibres, which are responsible for generating forceful contractions at high velocity. Despite the evolutionary conservation of α-actinin-3, approximately one every five Caucasians European ancestry totally deficient this protein, due to homozygosity a R577X polymorphism ACTN3 gene. This, together with results recent research on elite athletes, suggests that "null" XX might confer some advantage endurance performance events. To test hypothesis, we studied frequency distribution genotypes group 50 top-level male professional cyclists (26.9 ± 0.4 yrs [mean SEM]; V·O2max: 73.5 0.8 ml · kg-1 min-1). Their were compared those 52 Olympic-class runners (26.8 0.6 yrs; 73.3 min-1) and 123 healthy, sedentary controls. All subjects Caucasian, ancestry. No significant differences (p > 0.05) found between groups: RR: 28.5 %; RX: 53.6 % XX: 17.9 controls; 28.0 46.0 26.0 cyclists; 25.0 57.7 17.3 runners). indices (VO2peak or ventilatory thresholds) athlete carriers each genotype. In summary, although genotype may be detrimental sprint humans, gene does not appear an ability athletes sustain extreme performance.