Beschreibung:
<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>We have previously suggested that some of the mutations defining mitochondrial DNA (mtDNA) haplogroups J and K produce an uncoupling effect on oxidative phosphorylation and thus are detrimental for elite endurance performance. Here, the association between haplogroups J and K and physical performance was determined in a population-based cohort of 1036 Finnish military conscripts.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Following a standard-dose training period, excellence in endurance performance was less frequent among subjects with haplogroups J or K than among subjects with non-JK haplogroups (<jats:italic>p</jats:italic> = 0.041), and this finding was more apparent among the best-performing subjects (<jats:italic>p</jats:italic> < 0.001).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>These results suggest that mtDNA haplogroups are one of the genetic determinants explaining individual variability in the adaptive response to endurance training, and mtDNA haplogroups J and K are markers of low-responders in exercise training.</jats:p></jats:sec>