I'm a few months past 62, and returned to cycling last fall after my knees protested my AT hike attempt in May/June. At first it was to strengthen my quads but then I remembered how much I love cycling and decided my hiking can go to the back burner while I cycletourcamp. I haven't pedaled as far as you, so I'm not tired of cycling yet. I am willing to mix in a hike here and there, though, given an invite from the right party. Mostly, I think my walking technique is not smooth enough to click off 20 mile hiking days, but 75 mile biking days are eminently doable.