I'll be 64 in August and thankfully only have arthritis problems in my hands, wrists and feet. That still makes anything bodyweight for the upper body problematical unless I modify. Which I do, freely. I also have some lumbar spinal stenosis that DOES NOT like a lot of Pilates, so I do little of that
I'm also a BBT fan, although the last couple seasons are kind of
*I do LOTS of walking outdoors
*Water aerobics including deep water work with resistance gloves.
*Ocean swimming
*Non-power yoga--down dog is fine but no endless vinyasas please.
*Jessica Smith--I do some walking videos jogging on the rebounder for a little more intensity. I also use her weight work but modify the plank-y stuff
*Classical Stretch/Essentrics--I have seasons 4, 8, and 10 and kind of cycle through them; also have quite a few of the dvds
*Z-Team Zumba and Shine dance aerobics
*Kettlebells when the mood strikes; Margaret Richard for weights sometimes but I can take the repetitiveness only rarely
*I still love step but I can't do it too often or it aggravates my back. Love Rob Glick, Patrick G, guilty pleasure Ballroom Aerobics, and my once a month "do I still have it?" test, Gin Miller's Intense Moves.
I intend to keep moving until I can't any more.