I was diagnosed with rheumatism around 10 years ago and is under control apart from when I exercise, sometimes it flares up even when I don't exercise and is mainly located around my knees, so high impact activities are out and lunges etc that are putting pressure on the knees. Three years ago I ended up with bursitis in the hip which is just as painful, this usually flares up after I've walked quickly as my stride is long and I have over- mobility in the hip so they go further back than they should when I walk.
Never the less, I have not let this stop me ( no pain , no gain ).
I down right refuse to let this control me.
Today I am proud, I am bursting with joy, nursing my sore hips with a hot water bottle because I did more than the weights and walk for miles, I Ran, on the treadmill today I jogged at 4mph for 4 sets of 5 mins. I have never done this ever and I did it, even had to ring my partner because I was bursting with pride.
I still can't do it out side on concrete/tarmac but one day maybe.