Self-efficacy and planning seemed to be functional as proximal predictors of health behaviors, whereas health risk perception appeared to be a negligible factor. When predicting health behaviors, self-regulatory variables should be used in addition to the behavioral intention.

Young, middle-aged, and older adults in orthopaedic outpatient rehabilitation (N = 373) were randomly assigned to either an interviewer-assisted or a standard-care self-administered planning intervention. Physical activity planning consisted of specifying action plans to facilitate action initiation, and coping plans to overcome barriers. The interviewer-assisted condition led to more complete action plans and a longer duration of physical activities up to six months after discharge. Regarding coping planning, older and middle-aged adults benefited more from interviewer-assisted planning while younger adults benefited more from self-administered planning. Planning as such was found to be an effective tool for enactment irrespective of chronological age. The delayed effect of coping planning on enactment suggests that coping planning is important for long-term maintenance.

Although health risk perception appeared to be a negligible factor, action planning and recovery self-efficacy were effective predictors of physical exercise adherence.

A 'views-on-ageing'-component within a physical activity intervention affects change in physical activity via change in views on ageing. Views on ageing are a promising intervention technique to be incorporated into future physical activity interventions for older adults.

Objective-Stage assessments are examined to develop and test refined measurements that can be used for classifying individuals.Design-Stages were assessed in 1,850 persons in terms of their physical activity and dietary behaviors.Main Outcome Measures-Stages for both behaviors were compared to behavior and other test variables. Misclassification, sensitivity, specificity, receiver-operation-curves, and discontinuity patterns were computed. Discontinuity patterns were tested with trends across stages and planned contrasts between adjacent stages.Results-In comparison to previous studies, sensitivity (70% to 80%) and specificity (80% to 87%) were high. When using lower level criteria (such as less intensive activity), sensitivity was lower, whereas specificity was higher. When behavioral maintenance was assessed, results suggested that the temporal cut-off point between action and maintenance was equally optimal at different cut-off points. Applying contrast analyses, nonlinear trends across the stages and a match of 87% of predictions of stage differences resulted. Conclusion-Stageassumptions are supported in general, and refined stage assessment in particular. Levels of psychological variables (e.g., easiness, habit) may discriminate stages as well as or even better than temporal stage definitions. Keywords stages; misclassification; specificity; sensitivity; health behavior Behavior change toward a particular goal (such as smoking cessation) can be understood either as a continuous process or as a series of distinct stages that represent an ordered set of categories into which people can be classified. These categories reflect cognitive or behavioral characteristics, such as the motivation to perform a behavior or the habit of doing so for an