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.