I just turned 60 this year so I'm not too far ahead of you.
The things I have noticed is that I can still do what I want, but I have to not take anything for granted, have to do my homework. I went mountain goat hunting last year, and hopefully will go this year, but I exercise every day to be able to do that. There was a time I just grabbed my pack and went.
I am a volunteer fireman and EMT, and work with a much younger group. Another scene where I have to do more just to keep doing it.
Definitely worth the effort.
So far I have been blessed with good health, but I know my turn will come. I guess what I am getting at is focusing on what can still be done and doing it. What I can't do will come on it's own, don't need to welcome it in. I watch my wife fight cancer to a draw over the last ten years, and she still gets out and walks 5 miles a day, gardens, goes fishing with me, and she is 67. A good example for me to follow. She says every day is a gift.