Habit as mediator of the relationship between prior and later physical activity: A longitudinal study in older adults

• Prior physical activity (PA) is a good predictor of later PA.
• Habit is a proposed mediator of the relationship between prior and later PA.
• The SRHI was used as an operationalization of habit.
• Habit was found to be a mediator of the relationship between prior and later PA.
• The ASE/TPB model may benefit from incorporating habit.

ObjectivesHabit has been proposed as an explanation of why prior behavior is a good predictor of later behavior. This study examined whether habit mediates the relationship between prior and later physical activity (PA), within the framework of the attitude-social influences-efficacy (ASE) model and the theory of planned behavior (TPB).DesignA longitudinal design was used.MethodsA total of 1976 older adults completed questionnaires on ASE/TPB constructs and PA at baseline, intention at three months, habit at six months, and PA at twelve months.ResultsPath analyses showed that habit significantly mediates the relationship between prior and later PA, after ASE/TPB variables were taken into account.ConclusionsHabit is a partial solution to the question why prior PA is a good predictor of later PA. It is recommended to incorporate habit into the ASE/TPB model.