Sailing can provide pleasant exercise and stretching. As I get older, rowing is a real plus for core muscles. I feel that just a week or so after seasons begins when I'll row several miles every week.
Adjusting to a moving boat feels good for my agility. If you combine your sailing with hiking, you have a well rounded program of healthy exercise. Tools like electric winches can prolong that healthy lifestyle but I find two speed winches can fill that gap as well: at least up to a point. Then we're lucky to have these new electric tools.
Working on your boat, that's a little like building for me. It gets harder as I get older. But I can still find my pace after a period of none use, then it feels great again to build-make-fix.
The physical decline is fairly predictable each season.'Muscles,can you crank that mainsail up the track this season?' Mental attitude as I've seen it, is mysterious. Like an ON-OFF switch, it can be thrown at any time.