6MWD 6-min walk distance 6MWT 6-min walk test BMI body mass index COVID-19 coronavirus disease 2019 CPET cardiopulmonary exercise testing ESWT endurance shuttle walk test FEV 1 forced expiratory volume in 1 s HCP healthcare professional HRQoL health-related quality of life ILD interstitial lung disease IPF idiopathic pulmonary fibrosis ISWT incremental shuttle walk test LMICs low- and middle-income countries MCID minimum clinically important difference PR pulmonary rehabilitation QoL quality of life List of abbreviations