As far as regular exercise, my capacity has increased some but not what I would consider a lot. At 79 going on 80, I still try to do 30 to 45 minutes a day on my Teeter FreeStep Cross Trainer which is similar to an elliptical bicycle plus 10 minutes or so on an inexpensive ride and row machine I bought a few months ago. It's a pretty intense machine for getting your heart rate up quickly and I think is better for my core muscles and leg strenghth as it's similar to doing squats combined with rowing - https://sunnyhealthfitness.com/products/squat-exercise-trainer-sf-a020052. On days where I have to shovel snow or other outside tasks I'm not particulary fond of I generally don't do the inside exercising.

I do feel like I can do more than a few years ago when my PMR was active. I think it's good to have a goal to slowly increase the exercise activity as it begins to get easier for you just because it's a challenge and I like the hope of losing less muscle mass or slowing it way down.