My PMR history and concern about fitness level

It sounds to me as if you might have not only PMR but also something called myofascial pain syndrome (MPS). This has been shown to be caused by the same inflammatory substances, cytokines, as PMR except in PMR they are shed in the body in the early morning and are all through the body but in MPS the form trigger points which can be felt as knots in the muscles - in pairs on either side of the spine, in the shoulders, about rib level and in the low back. The muscles tend to go into spasm to protect themselves and can pinch or irritate nerves, leading to referred pain in the arms, ribs and buttocks, upper legs and low back depending on which trigger point is involved. It can be one-sided or bilateral and often mimics PMR pain although typically PMR is bilateral.  It is often found alongside PMR.  It often improves at higher doses of pred but then returns as the dose is reduced.

The best way of dealing with the trigger points is either steroid injections into the area or manual mobilisation which can be done by a physio or sports massage therapist (or a really good massage therapist).  Obviously these all usually require a doctor to cooperate with referrals but another option that has worked for quite a few people on the forums is Bowen therapy. Do google it and read about it. Searching "Bowen therapy therapists USA" should get you links to 2 sites, bowendirectory and americanbowen acadamy where you could identify a local practitioner. A study is being done in the north of England by the NHS to study its role in relieving persistent back pain. I, and others, have used it and found having these specific pains relieved meant a lower dose was enough for the PMR pain.

Your doctor may have recognised that you had PMR - but he went about treating it in totally the wrong way. A Medrol taper pack will never deal with it - PMR is a chronic illness requiring long term pred over a period of 2 or more years. You start at 15mg or so and reduce very gradually to find the lowest dose that manages the symptoms as well as the starting dose did.

Follow this link

https://patient.info/forums/discuss/pmr-gca-website-addresses-and-resources-35316

and you will find a "reading list" in the first post. The "Bristol paper" describes the diagnosis and management of PMR - written by top UK rheumatologists to assist GPs in the task. In the replies you will find a slow reduction plan which has been used successfully by quite a few patients on the forums, it has been approved by several rheumatologists when their patients have asked about using it and it is about to be used in a research study on PMR.

Your rheumy may think your PMR is atypical - I suppose it depends at what stage you find the people who don't show the "typical" symptoms are in the majority! About 1 in 5 have no raised blood markers and rheumatoid factor is rarely positive in PMR - and anyway, at least 10% of people who don't have an arthritis are positive for rheumatoid factor. By no means all people diagnosed with pMR have BOTH shoulder and hip pain/stiffness. Likewise, some people lose weight when on pred - it makes me lose my appetite but doesn't lead to weight loss! 

In PMR your muscles are intolerant of acute exercise and remain so even when the symptoms due to the inflammation have been relieved by steroids. The underlying autoimmune disorder that causes your immune system to attack your body by mistake remains active and fatigue is a common symptoms in almost all autoimmune disease. You will be able to build your fitness again - but you must take it very slowly when increasing what you can do - I have written a long post on that to someone else today. Increasing 5 min in how long you walk each day over a week will work - trying to increase by 5 mins every day probably won't.

Did the ER find anything? I developed atrial fibrillation which caused similar episodes to what you describe and my BP obviously varied - most of the time it was 130/80 when measured but there was later evidence it had been raised. It can happen with steroids but the cardiologist is confident mine is due to autoimmune damage done by the underlying cause of the PMR. It is well-managed medically.

Your history sounds sort of similar to mine.  My undertreated PMR led to  breathing problems as the inflammation went to my lungs.  Now that I am off oxygen, thank goodness,  and off high dose prednisone, one side of my lower torso is quite painful.  In the morning I stagger around grimacing at the pain.  At this point I take both celebrex and prednisone which, I know,  one is not supposed to do, but the alternative seems to be to lie in bed all day!  Forget exercise!!

      I was taught years ago how to handle trigger points.  Feel around till you find a spot that makes you go "ouch that hurts", then put pressure on the spot till the muscle relaxes.  This takes 30 seconds to a minute per spot.  I can endure the pain for that long, but it can be quite a painful thing to do to oneself.  

        The first problem I had was that I couldn't reach all the spots, so I bought this big plastic S shaped gadget from Amazon just for that purpose for about $25 for a back buddy. More than one company makes them.  Once you are in Amazon you can search for trigger point and find it.That really helped for awhile till the trigger points multiplied to such an extent and reappeared so often that I couldn't keep up.  That is when I first complained and was diagnosed with PMR.  Still, at times, that big plastic S comes in handy.  I have been trying it on the lower torso pain and it helps but it is awkward as I have to stand up to do it.