Atomic Habits: An Easy & Proven Way to Build Good Habits & Break Bad Ones · chapter 5 · id atomic-habits-c5-01-people-who-make-a-specific-pla

“People who make a specific plan for when and where they will exercise are more than twice as likely to follow through. 91% of the implementation intention group exercised vs 38% of control.”

needs contextconfidence: high⚠ extracted by pipeline, re-audit pending

Receipts

Milne, Orbell & Sheeran 2002, British Journal of Health PsychologyDOI registry: valid

Control: ~38% exercised. Motivation-only (PMT): ~35%. Implementation intention + motivation: ~91%. N=248 split three ways, one-week self-reported follow-up.

Gollwitzer & Sheeran 2006 meta-analysis, Advances in Experimental Social PsychologyDOI registry: valid

Meta-analysis of 94 studies found medium-to-large effect size d=0.65 for implementation intentions on goal attainment. Substantial but not "doubling."

Adriaanse et al. 2011 meta-analysis, AppetiteDOI registry: valid

Meta-analysis of eating behavior found small-to-medium effect d=0.51. Effects stronger in lab than field, stronger short-term than long-term.

This claim is a stable, citable object. If you can falsify a verdict, tell us — corrections are loud here.