I don't know why I'm posting this, but here it is.
About 20 years ago I suffered a heart attack and took a middle of the night trip in an ambulance to the emergency room.
After recovery, I went online and found information about fitness walking. I immediately started a program.
https://www.the-fitness-walking-guide.com/
I am 82 years old and just completed my morning walk. We live on a street that is 0.3 miles long. I walk 4 lengths of the street every day, at least 330 days a year.
I have no physical problems, no pain, and a good appetite. I see a doctor about once a year for a check up.
I encourage you other old dogs to start some sort of regular exercise program.
I just completed my morning walk in Galveston County Texas. It is a sunshiny morning in the 50's. A great day to be alive.