If you already have arthritis, exercise will reduce the pain and disability, partly because it stimulates the production of synovial fluid that lubricates the joints. There's another good reason to stay active! When you have arthritis, you will have less pain if you move your joints frequently; if you are sedentary, your joints will become stiff and even more painful. You may need to switch to forms of exercise that are easier on the joints, such as swimming or bike riding. Regular daily exercise is also recommended in arthritis because it improves overall muscle tone and balance and thus helps remove strain on the joints.