An intervention based on the predictions of Maddux's revised Theory of Planned Behaviour was designed to improve fitness training adherence of a group of elite netball players. The intervention consisted of a persuasive communication and time management workshop, which targeted the social cognitive constructs of the theory. We adopted a multiple baseline across-individuals design over 14 weeks with 17 elite netball players. Baseline training adherence data were collected over the first 7 weeks. The targeted social cognitive constructs were assessed at baseline, post-intervention and follow-up. Large effect sizes for changes in training adherence from baseline to post-intervention were noted for 13 players (76%). Post-intervention analysis revealed significant changes in two of the targeted variables, perceived vulnerability and attitude towards current behaviour, suggesting that the intervention was associated with cognitive changes. Data from an intervention check provided additional evidence to support the efficacy of the intervention. A follow-up assessment over an additional 7 weeks showed that players' training frequency remained improved. The results support the view that the revised Theory of Planned Behaviour can help inform interventions that enhance the training adherence of elite netball players.