1. Swansea University Medical School, Swansea University, Swansea, Wales, UK
2. Applied Sports Technology Exercise and Medicine Research Centre, College of Engineering, Swansea University, Swansea, Wales, UK
3. Norwich Medical School, University of East Anglia, Norwich, England, UK
4. College of Human and Health Sciences, Swansea University, Swansea, Wales, UK
5. Department of Paediatric Respiratory Medicine and Paediatric Cystic Fibrosis Centre, Children's Hospital for Wales, Cardiff, Wales, UK