After having open heart surgery, a constantly painful back, and knee surgery in my early 40.s. I decided I would need to change careers if I wanted to continue to work. Sleeping on the cold ground, carrying bear hides, and moose meat over mountains was not going to be a sustainable career, in to my 50's and 60,s. Also having to get wavers, and pass an FAA physical every two years was getting difficult. One bad word from a doctor and a career can be over in an instant.
I decided I would captain a private yacht in Mexico, in order to be able to work longer. Though I mostly give orders, and have others do the heavy lifting, I still have to do my share of physically demanding mechanic work, but compared to living and working in the Alaska bush it is a job made for sissies. I do have to pass a Coast Guard physical, but I only have to get one every 5 years, and they seem to be less strict than the FAA. I miss the rugged life of the mountains, but I made the right decision to switch jobs when I did. Since moving here I have had to get surgery on one shoulder, and will have to get another one done some day. The knee that was operated on years ago leaves me limping most days, and I will eventually have to get surgery.
I won't have to retire for many years, because as my body gives out I simply hire more of the physical work done. I gave up all of my hobbies, except bass fishing. I am very lucky my knee doesn't hurt when I pedal my Hobie, and my back pain only starts when I stand up after a day on the water. I told my wife the day I can't fish is the day she needs to either put me in a home, or the ground.
After hearing some of the stories in this thread, I feel very young and fortunate. Many here are much older, and have had much tougher lives, and still manage to get out and catch a few bass. I may have many aches and pains from stress on my body when I was young, but the memories are worth it. Besides now I can have an excuse to hand the rod off when a 200 pound tuna bites, and watch some young guy deal with the pain of landing it. Like others, I try to stretch and exercise in order to lesson the pain, but in the end I know the surgeons knife will eventually be needed. For some reason buying tackle seems to help more than exercise. Imagine that.