Nothing wrong with the age, just a matter of being a little more careful doing all the little things.
In my last stint with Left Coast (it's been a while), I ran back and forth from Texas to Georgia and back. I would typically take loads that went out the same time as an older guy. I think that was by design, as our safety guy liked us running together, but he never admitted it.
The old man was 85, and I swear he lived on peanut butter sandwiches on the road. Made me a few too!
We would go walking once we parked the trucks at the receiver at night waiting for them to get there the next morning. Also stopped regularly in Temple, GA and walked from the J over to Waffle House. I swear, you had to really step to keep up with him when he was walking. Seemed to be in awesome shape for an 85 year old, hell, I would have considered him to be in really good shape for a 50 year old.
After I left, the old man ended up falling out of the back of a trailer and broke his back. I heard about it a month or so after it happened, and they weren't sure if he would be able to walk again.
Getting around can be fine, just gotta be extra careful regarding what most of us would consider minor accidents.