If you're new to exercise, start by asking your doctor what activity level is right for you. For example, if you have acute back pain you may have to avoid exercise until your back has healed. Also, ask what types of exercise suit your condition. Water aerobics is often ideal for people with arthritis because it supports joints. Remember, exercise shouldn't hurt. If you notice an increase in pain, stop and tell your doctor. There may be other types of exercise that you can do.