This study will test the effectiveness of aerobic exercise on improving sleep in patients with systemic lupus erythematosus. The subjects will do treadmill 2 times per week, from 15-20 min. with low to moderate(55-65% maxCF) intensity exercise, so 30 min. until 4ª week. From the 5ª to 8ª week they will be able to make greater efforts to 35-40 min. totalizing 16 weeks. The control group will not do exercise and will receive education class about disease, health, sleep, 1 time per month.