NRF2 genotype improves endurance capacity in response to training.

The aim of this work was to examine the association between the polymorphisms in nuclear respiratory factor (NRF2) gene and endurance capacity measured prior to and after an 18-wk endurance training program in young Chinese men. The phenotypes measured were running economy (RE) and VO(2max). The RE was determined by measuring submaximal VO(2) for 5 min at a constant running speed of 12 km x h (-1) and VO(2max) was measured during an incremental test to volitional exhaustion. Genomic DNA was extracted from white cells of peripheral blood and the genotypes were examined in SNPrs12594956, rs8031031 and rs7181866 by PCR-RFLP. Genotype distributions were in Hardy-Weinberg equilibrium at three loci, and linkage disequilibrium was observed (LD D' = 1 and r (2) = 0.903) between rs8031031 and rs7181866. The VO(2max) was associated with rs12594956 at baseline while the training response of VO(2) at RE, was associated with rs12594956, rs8031031 and rs7181866. When the three SNPs were considered together, those carrying the ATG haplotype had 57.5 % higher training response in VO(2) at RE (p = 0.006) than non-carriers. In conclusion, polymorphisms in NRF2 gene may explain some of the between-person variance in endurance capacity.