I’ve known several hikers in their 70’s and beyond. One of the things that has kept me hiking is knowing that it is an activity I can enjoy for many more years (and I’ve been doing it now for more than 20.) My husband did his 4th long distance hike at age 66 and intends to do his next one once he gets his new knee.
Are you hiking now? How fit are you? If you’re continuously active, you should be able to hike when you retire. It’s much harder starting from scratch.
The biggest issue I’ve noticed with older hikers is that things take longer to heal than for younger hikers. A strained tendon can heal in a few days for a 30 year old but may weeks if you’re older. You learn to live with pain on a daily basis. Joints may be more of an issue too. Years of abuse take a toll on ankles and knees. Ibuprofen is your friend.
Older hikers tend to be steady hikers - hiking from dawn to dusk day after day. Younger hikers are more likely to be jackrabbits - racing to town then taking several days off, or doing long miles one day and very short miles the next.
A lot of AT hikers are retired folks. You’ll have lots of company.
Ginny