On the 'younger' end here (late 20s). Usually 1 or 2 days w/o is still good to go. I try to do at least 3 before going for a session.

I've done a full week before and definitely saw a massive increase in the amount.

Been slipping recently because of the holidays though and need to discipline myself again to get back to the 3 days. Had a FS session recently and went pretty quickly, pretty sure the ML was disappointed haha, I definitely was.