Abstract

There is a growing interest in examining interindividual differences in adaptations to exercise training and classifying individuals as “responders” or “low-responders.” Despite this increasing popularity, the mechanisms underlying individual differences in training responses remain largely unclear. This chapter reviews the available evidence highlighting possible genetics and biological mechanisms that may explain individual differences in adaptations to exercise training. Prior to exploring possible mechanisms, we begin with a brief overview of statistical considerations associated with analysing, interpreting, and discussing individual responses to exercise training. We then conclude by acknowledging future large-scale collaborative projects, such as the Athlome consortium, that are anticipated to provide important insight toward the mechanisms underlying individual differences in adaptations to exercise training.