Make it observable
Choose an action you can describe without turning it into a body or disease outcome promise.
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planner
90-day experiment planner
Design one bounded 90-day experiment with a backup, stop rule and review date. The aim is learning, not compliance.
Use it thoughtfully
Plan the restart
Write the smallest useful version and the cue for resuming after disruption.
Your worksheet
A bounded experiment that can be revised without judgement.
Boundaries and sources
This tool does not
- Does not promise that twelve weeks will transform long-term risk or require a commercial intervention.
Evidence links
Content owner: Healthspan content and clinical governance · Reviewed: 2026-07-13 · Next review due: 2027-07-13
- The behaviour change wheel: a new method for characterising and designing behaviour change interventionsImplementation Science · reviewed 2026-07-13
- Implementation intentions and goal achievement: a meta-analysisAdvances in Experimental Social Psychology · reviewed 2026-07-13
- Self-regulatory behaviour change techniques in interventions to promote healthy eating, physical activity, or weight loss: a meta-reviewHealth Psychology Review · reviewed 2026-07-13