GPS-based activity space exposure to greenness and walkability is associated with increased accelerometer-based physical activity - Marquet Sardà, Oriol (Universitat Autònoma de Barcelona. Institut de Ciència i Tecnologia Ambientals) ; Hirsch, Jana A. (Drexel University. Department of Epidemiology and Biostatistics) ; Kerr, Jacqueline (University of California San Diego. Department of Family Medicine and Public Health) ; Jankowska, Marta M. (Beckman Research Institute) ; Mitchell, Jonathan (Children's Hospital of Philadelphia (Pennsilvània)) ; Hart, Jaime E. (Brigham and Women's Hospital (Boston, Estats Units d'Amèrica)) ; Laden, Francine (Brigham and Women's Hospital (Boston, Estats Units d'Amèrica)) ; Hipp, J. Aaron (NC State University) ; James, Peter (Harvard Medical School)