What does it mean that commitment stacking?

Link new commitments to existing reliable behaviors.

Example: You have meditated every morning for two years. It is the most reliable behavior in your life — you do it without thinking, without deciding, without negotiating with yourself. Now you want to start journaling. Instead of creating a new standalone commitment ('I will journal every day'), you stack the new commitment onto the existing one: 'After I finish meditating, I will open my notebook and write three sentences.' The meditation is already a solved problem — automatic, effortless, locked in. By chaining the journal commitment to it, you borrow the older behavior's momentum. You are not starting from zero. You are drafting behind something that already works.

Try this: Map your five most reliable daily behaviors — the things you do every day without fail, without thinking, without any structural support. These are your anchors. Now identify one commitment you have been struggling to keep. Write a commitment stack in this format: 'After I [reliable anchor behavior], I will [new commitment scaled to two minutes or less].' Install it today. Run it for seven days. At the end of the week, assess: did the anchor hold the new behavior in place? If yes, expand the scope slightly. If no, the anchor was wrong or the new behavior was too large — diagnose which one and redesign.