@woot - I had another thought about "improving" - sometimes, with a progressive disease, and dare I say it, age, maybe the best idea is to maintain, with tiny increments toward improvement.
I always remember trying to get back in shape too quickly as a runner after childbirth in my 30's - the doctor told me "your body is under stress with 2 small children, recovery and nursing - slow down." Instead of pushing to add 10% per week to my distance, she wanted me to drop to 2% - hard advice for a Type A person, but it was the key - my endurance began to slowly improve without more fatigue or injury.

After MAC, remembering that decades old advice, I started with 1/4 mile daily walks, in 4 months I was up to 1 mile - not much but it got me on track. Today, I begin adding to my post-flare 1 1/2 miles - not by trying to go 2 or 3 miles, just 5 more minutes.
Sue