Proof of concept of a treatment for fibromyalgia based on physical activity, psychological support, and exposure to nature (NAT-FM) - Sanabria-Mazoa, Juan P. (Universitat Autònoma de Barcelona. Research Group on Stress and Health) ; Serrata, Mayte (Universitat Autònoma de Barcelona. Research Group on Stress and Health) ; Mateo Canedo, Corel (Universitat Autònoma de Barcelona. Research Group on Stress and Health) ; Feliu-Soler, Albert (Universitat Autònoma de Barcelona. Research Group on Stress and Health) ; Almirall, Míriam (Hospital Universitari Vall d'Hebron) ; Méndez Ulrich, Jorge Luis (Universitat Autònoma de Barcelona. Research Group on Stress and Health) ; Luciano, Juan V (Institut de Recerca Sant Joan de Déu) ; Sanz Ruiz, Antoni (Universitat Autònoma de Barcelona. Research Group on Stress and Health)