The proposed study will examine the efficacy of a self-paced, home-based aerobic conditioning program, with limited supervision, for managing Fibromyalgia (FM). The study will further examine whether symptom improvements are the result of objective changes in aerobic conditioning as reflected in exercise testing. Patients will undergo quantitative pressure algometry (to assess muscle tender points), and will complete pain ratings and functional / psychological measures. Data analysis will determine whether decreases in pain and other symptoms of FM are associated with changes in conditioning as documented by MET. Psychological measures will be tested as predictors of treatment failure.