Shrink the habit until it is guaranteed

Cut the behavior down until skipping it would be more effort than doing it.

Why it works

Consistency is the only thing that builds a habit, and the biggest threat to consistency is the size of the ask on bad days. Shrinking the behavior to something trivially small — one push-up, read one line — removes the variability: it can be done when you are tired, sick, or busy. You are optimizing for "never zero," because a habit done at 100% size half the time loses to a micro version done every day.

How to do it

1. Take your intended habit and cut it until you are slightly embarrassed by how small it is.
2. Test it against your worst realistic day — if you could not do it then, shrink it further.
3. Lock the micro size as the real requirement, not a fallback you feel guilty about using.

Evidence

Grounded in research on activation energy/friction as the failure point of behavior and on habit formation through repetition. The "absurdly small" framing is a practitioner heuristic applying those findings. Gardner et al. (2012) translate the same repetition mechanism into general-practice guidance, showing that keeping the behavior simple and repeatable is what lets it become habitual. (mechanistic)

There is no studied "correct" minimum size; the principle is reducing the cost to start until consistency is guaranteed.

Sources

• Lally et al. (2010), repetition drives automaticity (median ~66 days), European Journal of Social Psychology
• Lally, P., van Jaarsveld, C. H. M., Potts, H. W. W., & Wardle, J. (2010). How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology, 40(6), 998–1009.
• Gardner, B., Lally, P., & Wardle, J. (2012). Making health habitual: the psychology of 'habit-formation' and general practice. British Journal of General Practice, 62(605), 664–666.

Common mistake

Setting the micro size where you think you "should" be able to do it instead of where you can do it on your worst day, so it fails the moment life gets hard.