Exercising with psoriatic arthritis isn't always the easiest. The autoimmune disorder targets areas where tendons and ligaments connect to bone, causing joint pain, swelling, and stiffness. Exercise, meanwhile, requires those joints to move smoothly and without pain. It’s tempting to think you should minimize movement, but that’s not the case. “Exercise can actually reduce swelling and stiffness, while strengthening the muscles that surround and stabilize the joints,” says Lauren Smith, P.T., a physical therapist at the Hospital for Special Surgery in New York City. Translation: Regular exercise can ease pain associated with psoriatic arthritis—but only if you heed the advice that follows.