Planning bridges the intention–behaviour gap: Age makes a difference and strategy use explains why

Objective: This study examines age-differential association patterns between intentions, planning and physical activity in young and middle-aged individuals. The effectiveness of planning to bridge the intention–behaviour gap is assumed to increase with advancing age. We explore the use of behaviour change strategies that include selection, optimisation and compensation (SOC) as underlying mechanisms for age differences. Methods: In N = 265 employees of a national railway company (aged 19–64 years), intentions, planning, SOC strategy use and physical activity were assessed at baseline (Time 1) and again 1 month later (Time 2). Hypotheses were tested in two different path models. Results: Age moderates the extent to which planning mediates the intention–behaviour relation due to an increasing strength of the planning–behaviour link. As a possible psychological mechanism for these age differences, we identified SOC strategy use as a mediator of the age by planning interaction effect on physical activity. Conclusion: These findings suggest differential mechanisms in behaviour regulation in young and middle-aged individuals.