West, Daniel W D; Doering, Tho M; Thompson, Ja M; Budiono, Boris P; Lessard, Sarah J; Koch, Lauren G; Britton, Steven L; Steck, Roland; Byrne, Nuala M; Brown, M A; Peake, Jonathan M; Ashton, Kevin J; Coffey, Vernon G
What is the central question of this study? The extent to which genetics determines adaptation to endurance versus resistance exercise is unclear. Previously, a divergent selective breeding rat model showed that genetic factors play a major role in the response to aerobic training. Here, we asked: do genetic factors that underpin poor adaptation to endurance training affect adaptation to functional overload? What is the main finding and its importance? Our data show that heritable factors in low responders to endurance training generated differential gene expression that was associated with impaired skeletal muscle hypertrophy. A maladaptive genotype to endurance exercise appears to dysregulate biological processes responsible for mediating exercise adaptation, irrespective of the mode of contraction stimulus.