I'll say you're staving off "old age" pretty well. You look AMAZING!!!
I have to be careful of my knees, so I'm starting off slow, in a Body for Life kind of workout. Here's the plan:
Day 1: upper body
Day 2: HIIT
Day 3: lower body
Day 4: HITT
Day 5: upper body
Day 6: HIIT
Day 7: rest
The next week you start out with lower body, so you're only working upper or lower body twice in a week.
It's pyramid approach. You do 12 reps, then 10 reps, then 8 reps, then 6 reps, and back to 12. You start with light weights and progress with each set. Today I worked the upper body with free weights at 3 lbs, 5, 8, and 10.
Tricep dips (lying on bench)
Pullovers (2 dumbbells in one hand, lower over head behind you; you're lying down)
Then with the Bowflex I did a couple versions of lat pulldowns.
I don't know the real names for the things I do, but I know they're "real" moves.
Then I did just a half mile on the treadmill, incline of 2, at 2.8 mph ... about 15 minutes. I used to love to walk and walk and walk and walk. Now the medial meniscus on both knees really hurts when I do. I don't even know if I still have a medial meniscus on my replaced knee. I shredded it on my left knee, so it's no wonder it hurts. I'm going to have to take the HIIT/cardio very slowly.
My plan is to do either HIIT or, if that's too hard on my knees, just steady-state cardio and alternate it from the recumbent bike, the treadmill, and the elliptical.
I'm very lucky in that I all have this equipment (and more) in our basement. I also have a ballet barre, a Total Gym, and some gimmicky other things. Plus floor mats, yoga equipment (blocks and straps), a large ball, etc.
If only I'd use it ...
Well, I'm starting to now!