Physical activity can be rewarding and lead to anxiety reduction, and physical activity levels in the general population are heritable, suggesting individual differences in the degree to which physical activity is reinforcing via biobehavioral pathways. Increases in physical activity are often associated with positive mental health outcomes, though more is not always better. For example, up to 40% of individuals with bulimia nervosa and up to 60% of those with anorexia nervosa present with driven exercise (exercising in a driven manner to control weight and shape). Driven exercise is a serious, concerning, and understudied eating disorder symptom. Existing research points towards compulsivity and general propensity to exercise as potential risk factors for driven exercise. At present, our understanding of the developmental etiology of driven exercise is poor, and the extent to which this symptom relates to patterns of PA during development is unknown.
We will examine risk for driven exercise in the ALSPAC cohort by identifying trajectories of physical activity during development and identifying whether these trajectories associate with driven exercise and eating disorder diagnoses in adolescence and emerging adulthood. We will then investigate the developmental timing and predictive strength of driven exercise in relation to eating disorder onset and maintenance. Finally, we will evaluate the degree to which genetic risk profiles inform risk for driven exercise.