PURPOSE: Accessible interventions to train patients with chronic obstructive pulmonary disease (COPD) are needed. We designed urban trails of different intensities (low, moderate and high) in different types of public spaces (boulevard, beach and park). We aimed to validate the trails' design by assessing the physiological response to unsupervised walking trails of: (1) different intensities in COPD patients, and (2) same intensity from different public spaces in healthy adults. METHODS: On different days and under standardized conditions, 10 COPD patients walked the three intensity trails designed in a boulevard space, and 10 healthy subjects walked the three intensity trails in three different spaces. We measured physiological response and energy expenditure using a gas analyzer. We compared outcomes across trails intensity and/or spaces using mixed-effects linear regression. RESULTS: In COPD patients, physiological response and energy expenditure increased significantly according to the trails intensity: mean (SD) peak [Formula: see text]O2 15.9 (3.5), 17.4 (4.7), and 17.7 (4.4) mL/min/kg (p-trend = 0.02), and MET-min 60 (23), 64 (26), 72 (31) (p-trend<0.01) in low, moderate and high intensity trails, respectively. In healthy subjects there were no differences in physiological response to walking trails of the same intensity across different spaces. CONCLUSIONS: We validated the trails design for the training of COPD patients by showing that the physiological response to and energy expenditure on unsupervised walking these trails increased according to the predefined trails' intensity and did not change across trails of the same intensity in different public space. Walkable public spaces allow the design of trails that could be used for the training of COPD patients in the community.

The study was funded by grants fromSupported by Fondo de Investigacion Sanitaria,Ministry of Health, Spain (FIS PI11/01283), integratedinto Plan Estatal I+D+I 2013-2016 and co-funded byISCIII-Subdirección General de Evaluación yFomento de la Investigación and Fondo Europeo deDesarrollo Regional (FEDER); Spanish Society ofPneumology and Thoracic Surgery (SEPAR 147/2011and 201/2011), and Catalan Society of Pneumology(SOCAP Fisioteràpia 2013). Anael Barberan-Garcia had personal funding from Agaur 2014-SGR-661,Catalan Government.