> But you and I both know of 90 year olds that are 'younger' than some 60 year olds.
I once had a rough hike at Half Dome that went deep into the early morning hours (a friend, who was an experienced alpine climber, made the horrible decision to bring his girlfriend at the time who had never even been on a hike before but was "in shape," and so they thought it would "be fine" -- it was NOT) and it was a total mess. We make it back to the trailhead around 2AM and a van pulls in. A 95 year old woman got out with her support team, they were starting the hike up so she could catch the sunrise from Half Dome.
I once had a rough hike at Half Dome that went deep into the early morning hours (a friend, who was an experienced alpine climber, made the horrible decision to bring his girlfriend at the time who had never even been on a hike before but was "in shape," and so they thought it would "be fine" -- it was NOT) and it was a total mess. We make it back to the trailhead around 2AM and a van pulls in. A 95 year old woman got out with her support team, they were starting the hike up so she could catch the sunrise from Half Dome.