That's tricky, and it's different for everybody with fibromyalgia. Don't push too much—do short bursts at a time. For instance, rather than exercising for a full hour, you might do 10 minutes, 6 different times during the day. Give yourself a good cooldown and warm up time, and monitor what bothers you and what doesn't. Also, it can help to have a physical therapist guide you as to exactly what exercises to do and when.