I've been working up to getting back full tilt at the gym after about a 17 year layoff and being a smoker for that time. Been walking outdoors around 7 miles a day. Started back at the gym today. Treadmill for an hour at a distance of 4.5 miles of jogging/walking. Will start with some weight lifting tomorrow.
Ah, yes...that' 50's plus push...
when you realize you're going downhill faster and up your game trying to fight it.
Good luck!
I'm 77 and still working at it!