It turns out that for endurance runners, it may be in the genes.
Nir Eynon and his colleagues at the Wingate Institute, plus Alberto Alves from the University of Porto, compared elite endurance runners (who had competed internationally) with long distance runners who had only competed nationally, sprinters, and healthy non-athletes. In particular, the researchers were looking at the ‘nuclear respiratory factor 2’ (NRF2) gene, which encodes a mitochondrial transcription factor. In other words, our cells’ power plants depend on NRF2. In addition, NRF2 is thought to be involved in mitigating exercise induced oxidation and inflammation.The scientists found that a particular NRF2 allele occurred much more frequently in elite endurance runners than in sprinters (80% of the time, vs. 46% of the time). This particular gene did not differ significantly between the sprinters and the non-competitive controls.