Genetic polymorphisms related to VO2max adaptation are associated with elite rugby union status and competitive marathon performance

Purpose: Genetic polymorphisms have been associated with the adaptation to training in maximal oxygen uptake (V̇O2max). However, the genotype distribution of selected polymorphisms in athletic cohorts is unknown, with their influence on performance characteristics also undetermined. This study investigated whether the genotype distributions of three polymorphisms previously associated with V̇O2max training adaptation are associated with elite athlete status and performance characteristics in runners and rugby athletes, competitors for whom aerobic metabolism is important. Methods: Genomic DNA was collected from 732 men, including 165 long-distance runners, 212 elite rugby union athletes and 355 non-athletes. Genotype and allele frequencies of PRDM1 rs10499043 C/T, GRIN3A rs1535628 G/A and KCNH8 rs4973706 T/C were compared between athletes and non-athletes. Personal best marathon times in runners, as well as in-game performance variables and playing position of rugby athletes, were analysed according to genotype. Results: Runners with PRDM1 T alleles recorded marathon times ~3 min faster than CC homozygotes (02:27:55 ± 00:07:32 h vs. 02:31:03 ± 00:08:24 h, p = 0.023). Rugby athletes had 1.57 times greater odds of possessing the KCNH8 TT genotype than non-athletes (65.5% vs. 54.7%, χ2 = 6.494, p = 0.013). No other associations were identified. Conclusions: This study is the first to demonstrate that polymorphisms previously associated with V̇O2max training adaptations in non-athletes are also associated with marathon performance (PRDM1) and elite rugby union status (KCNH8). The genotypes and alleles previously associated with superior endurance training adaptation appear to be advantageous in long-distance running and achieving elite status in rugby union.