Long-term relations between intentions, planning, and exercise: a 3-year longitudinal study after orthopedic rehabilitation.

OBJECTIVE Planning has been hypothesized to operate as a mediator linking intentions to health behaviors. To explore the temporal variation of these constructs and their interrelationships, a long-term study of intentions, planning, and physical activity was conducted. METHOD A sample of 328 individuals in orthopedic rehabilitation provided data at five measurement occasions over 3 years after their discharge from rehabilitation. A process-oriented approach combining mediation analysis and latent growth curve (LGC) modeling was applied. RESULTS The orthopedic rehabilitation led to an initial increase in planning and behavior, followed by a decrease after 6 months and stabilization for the next 2.5 years. Intention revealed a slight but constant decrease for 6 months and remained stable up to 3 years after rehabilitation. The mediation model confirmed planning as mediator between intention and physical activity in former rehabilitation participants. CONCLUSIONS Prior evidence on the mediating role of planning in the intention-behavior relation is corroborated and extended by the present findings at the level of long-term processes. Planning can and should be integrated in rehabilitation treatment programs to facilitate sustainable recovery.