I used a knee brace when my knees were really bad. My doc suggested the elastic ones that volleyball players use. He had me wearing the all the time for awhile, alleging that keeping them warm (which these braces certainly did!) would keep them moving more fluidly. I ended up with 2 pair, taking the padding out of one to use most of the time. I left the padding in the others for times when I had to be on my knees. Really helped. I'm not sure that they'd be ideal for exercise, but certainly not too expensive to try.