At 63 I'm still going strong.
I hike with the Las Vegas area Sierra Club and the "Meetup" online hiking group to stay in shape for backpacking.
At present I'm purchasing more and more lightweight equipment for summer camping. That's why I'm at this forum and likely why you're here too.
Good luck and, as they used to say in the '60s:
"There are no comfortable backpacks. Some are just less uncomfortable than others."