Does situation specificity affect the operation of an implementation intention intervention to increase physical activity?

Abstract

Background: Interventions that ask participants to link critical situations with appropriate responses (implementation intentions) have shown promise in increasing physical activity. Whether the specificity of the stated critical situation influences the effectiveness of an implementation intention-based intervention to increase physical activity is tested. Methods: Office workers (N=133) were allocated to: (a) form implementation intentions using a “volitional help sheet†that provided 10 specific critical situations; (b) form implementation intentions using a “volitional help sheet†that provided a single generic critical situation; or (c) think about critical situations and appropriate responses, but not form implementation intentions. Findings: At two-month follow-up, participants who formed implementation intentions reported engaging in significantly more vigorous physical activity than those in the control condition (d = 0.57). There were no significant differences between participants between the two implementation intention conditions (d = 0.04). Discussion: Situation specificity did not affect the operation of an implementation intention-based intervention to increase physical activity meaning that participants may not need to be offered exhaustive lists of specific critical situations with which to form implementation intentions.