I recently turned fifty. I was never particularly athletic as a youngster, and I think that I'm probably as fit and strong now as I was in my twenties (except where archery is concerned).
I walk half an hour into town to get the train to work each morning, same walk back home each evening but often with a few kilos of beer, meat or veg in a rucksack. Some mornings, I'll just set off into the woods with just a pocket knife and a couple of apples in my pocket, put one foot in front of the other and listen to the birds, and keep on going for six or seven hours. The land here is as flat as a pancake, though, and it can get a bit boring.
I ride horses every Sunday morning for an hour, and help feeding afterwards, and do an extra hour or two of a specialised class (last week was jumping) every few weeks. From time to time, I go out on a full day's ride: three or four hours, a two hour break, then another three or four hours. At the end of July, I'm going for a full week away: a two day ride to get to a gathering, then three days of activities (horseback archery and cattle rounding, among other things).
This weekend, I found myself a little anvil, 95kg, so I'm going to start swinging a hammer a bit more often. Oh, and a got myself a bow towards the end of last year; I'm taking up archery after a break of almost thirty years. I brought my old bow from my mum's house in December, but I'll not be pulling that 45lb bow for a while yet!
My eyesight has declined a bit, starting in about 2013, so I have glasses for reading. Other than that, and finding that I wake up much, much more easily in the morning than when I was younger, the only changes have been because of little injuries, and even there it's nothing more than a very minor inconvenience.