According to studies cited by Mark Liponis, MD, Medical Director at Canyon Ranch in his 2007 book UltraLongevity, exercise can help calm an overactive immune response and lower CRP levels. Furthermore, studies show that rhythmic exercise is particularly effective, and in one of the studies swimmers and rowers had the lowest CRP levels.
Some other suggestions for rhythmic exercise:
rebounding on a mini-trampoline
dancing - swing, polka, English country, contra-dancing, ballroom