The risk factors for compulsive exercise are unknown. This study aims to explore longitudinal sociocultural risk factors for compulsive exercise, using a 12-month prospective design. A sample of 332 male and female adolescents (aged 13-15 years at baseline) completed self-report measures of sociocultural risk factors and compulsive exercise at baseline and eating disorder psychopathology and compulsive exercise at 12-month follow-up assessment. Hierarchical regressions found that family and peer messages to become more muscular predicted compulsive exercise in boys, whereas feeling pressure from the media to be thin was a significant predictor of compulsive exercise in girls. These relationships remained significant when controlling for eating disorder psychopathology but became nonsignificant when initial levels of compulsive exercise were entered into the model. The findings suggest that sociocultural risk factors may contribute to the development of compulsive exercise but future research should utilise a younger sample and employ a longer follow-up period to identify true longitudinal effects. Copyright © 2014 John Wiley & Sons, Ltd and Eating Disorders Association.