Unfortunately, more and more often, I am called out on a SAR incident to look for an older person who has wandered away from his or her safe place, either their own home, or a care facility. Sometimes it is a hunter who has hunted the same woods for 60 or more years, whose family will usually say "he sometimes has short term memory problems". Most often it is much more severe than the family knows or is willing to admit. Many times those kinds of SAR incidents do not end happily.
On the other hand, as a canoe racer I see plenty of older folk in marathon canoe races. there is an 80+ yr old guy who consistently beats my butt on the water and on the portages ( I'm in my 60s). A class of "super veteran racers" (in their 70s and beyond) was recognized in last week's Adirondack 90 mile canoe race.