Gollwitzer & Sheeran 2006, implementation intentions and goal achievement (meta-analysis)

Meta-analysis of 94 independent tests of implementation intentions, concrete ‘if situation Y, then I will do X’ plans that specify in advance when, where and how an action will be taken. Forming an implementation intention had a medium-to-large effect on goal attainment (d ≈ 0.65). The plans worked by pre-committing the action to a specific cue, which helped people start on time, shield the behaviour from distraction, and disengage from failing efforts. The mechanism, binding a specific cue to an intended action, is the same one habit formation relies on, so if-then planning and context-based habit approaches complement each other. Large and highly cited, but not exercise-specific, so the effect should be tempered when applied to running.