Commitment isn't tested on the day you write the goal down. It gets tested on a wet Tuesday when you're tired, the thing is optional, and no one would ever know.
Most commitments convert quietly into intentions right about then. Not dramatically — you just don't do it, twice, and by the third time it isn't really a plan.
Decide now what the minimum version looks like. Ten minutes. One page. Small enough to survive a bad day, because bad days are what it has to survive.