@matt3134,
I've had it as a vague dermatalogic diagnosis that I don't trust, since I know a bit about serious psoriasis and psoriatic arthritis, in passing, from a past career. It was either slightly that or exzema or dermatitis. I too doubt exercise is in any way directly related, but I've no idea of any data on that.
Exercise is generally a good idea, but should be wisely worked out as to starting into it and progressing.
Look up the Mayo Clinic site, regarding psoriasis, that may be helpful.