I think wwa means 100% certainty that you'll stick to the precommitted course of action. But that isn't what people mean when they say "precommitment", they mean deliberately restricting your own future actions in a way that your future self will regret or would have regretted had you not precommitted, or something like that. The restriction clearly can't be 100% airtight, but it's usually pretty close; it's a fuzzy category.
r/Fitness does a weekly "Moronic Monday", a judgment-free thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. I thought this seemed like a useful thing to have here - after all, the concepts discussed on LessWrong are probably at least a little harder to grasp than those of weightlifting. Plus, I have a few stupid questions of my own, so it doesn't seem unreasonable that other people might as well.