It’s true that half an hour a week is enough to learn a few technique changes that can make the stroke more efficient, and thus faster. But even my adult private lessons, who come once a week for a half-hour of stroke correction plus another few times a week to practice, rarely improve their two-length (50 m) time by more than a second or two. Improving your swimming technique takes more than knowing what to do.
Shouldn’t you improve to a plateau? At least in the limiting case where you have not swum at all in a while?
It’s true that half an hour a week is enough to learn a few technique changes that can make the stroke more efficient, and thus faster. But even my adult private lessons, who come once a week for a half-hour of stroke correction plus another few times a week to practice, rarely improve their two-length (50 m) time by more than a second or two. Improving your swimming technique takes more than knowing what to do.