Journal of Back and Musculoskeletal Rehabilitation 28 (2015) 609–619 609 DOI 10.3233/BMR-140562 IOS Press Review Article Effects of exercise on functional aerobic capacity in adults with fibromyalgia syndrome: A systematic review of randomized controlled trials Antonio García-Hermoso a , Jose M. Saavedra c,∗ and Yolanda Escalante b a Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Talca, Chile b Facultad de Ciencias del Deporte, AFIDES Research Group, Universidad de Extremadura, Cáceres, Spain c Physical Activity, Physical Education, Sport and Health Research Centre, Sports Science Department, School of Science and Engineering, Reykjavik University, Reykjavik, Iceland Abstract. BACKGROUND: Patients with fibromyalgia present a reduced capacity of upper and lower limb physical performance and affect their independence in performing everyday activities. OBJECTIVE: The purpose of the present systematic review was to summarize evidence for the effectiveness and structure of exercise programs on functional aerobic capacity in patients with fibromyalgia syndrome. METHODS: Keyword searches were made of seven databases. The systematic review was limited to English language studies of people with FM that evaluated the effects of exercise programs on functional aerobic capacity (6-minute walk test). RESULTS: The criteria for inclusion were satisfied by 12 randomized controlled trial (RCT) studies. The main cumulative evidence indicates that the programs based on aerobic exercise alone and on aquatic exercises have large (effect size = 0.85) and moderate (effect size = 0.44) effects. CONCLUSIONS: Aerobic and aquatic exercises at the proper intensity favour the increased functional aerobic capacity of fibromyalgia patients; however, most works do not adequately detail the intensity of the exercises. Moderate intensity exercise (aerobic and aquatic exercise) performed at least two times per week and 30–60 minutes a day is effective for increasing functional aerobic capacity, favouring the daily activities of daily living in this population. Keywords: Fitness, strength, aerobic exercise, aquatic exercise 1. Introduction Fibromyalgia (FM) is a syndrome of unknown ætiology characterized by chronic and diffuse mus- culoskeletal pain accompanied by multiple somatic symptoms. The diagnosis is made according to the * Corresponding author: Jose M. Saavedra, Sports Science De- partment, School of Science and Engineering, Reykjavik University, Menntavegur 1, Nauthólsvík, 101 Reykjavík, Iceland. Tel.: +354 599 6343; Fax: +354 599 6201; E-mail: saavedra@ru.is. classification criteria established in 1990 by the Amer- ican College of Rheumatology (ACR) [1]. The Amer- ican Pain Society’s Guideline for the Management of Fibromyalgia Syndrome Pain in Adults and Chil- dren recognizes additional symptoms such as fatigue, headache, sleeplessness, psychological disorders, and cognitive dysfunction which can affect sufferers’ over- all health and quality of life [2]. The syndrome’s preva- lence in the overall population has been reported to range from 0.5% to 5%, and up to 15.7% in a clinical setting [3]. It affects about eight times more women than men [4]. ISSN 1053-8127/15/$35.00 c  2015 – IOS Press and the authors. All rights reserved