High–intensity exercise training induces the oxidative modification of malate dehydrogenase 2 in skeletal muscles

•High–intensity training causes mitochondrial dysfunction.•Oxidative modification in muscle mitochondria is higher following intense training.•Oxidative modifications of MDH2 were higher in the muscles of exercised mice.•A mitochondrial fission factor was increased by exercise.•The modifications may limit effective adaptation in response to exercise training.