1 Royal Brompton & Harefield Hospitals, Guy's and St.Thomas' NHS Foundation Trust, London, UK W.Man@rbht.nhs.uk.
2 Centre for Exercise and Rehabilitation Science, NIHR Biomedical Research Centre - Respiratory, Glenfield Hospital, University Hospitals of Leicester NHS Trust, Leicester, UK.
3 Department of Respiratory Sciences, Institute for Lung Health, University of Leicester, Leicester, UK.
4 Royal Brompton & Harefield Hospitals, Guy's and St.Thomas' NHS Foundation Trust, London, UK.
5 Department of Health Sciences, College of Health Medicine and Life Sciences, Brunel University London, London, UK.
6 University Hospitals Sussex NHS Foundation Trust, Brighton, UK.
7 Brighton and Sussex Medical School, Brighton, UK.
8 School of Health and Social Care, Edinburgh Napier University, Edinburgh, UK.
9 Department of Sport, Exercise and Rehabilitation, School of Health and Life Sciences, Northumberland University Newcastle, Newcastle Upon Tyne, UK.