Department of Surgical and Interventional Sciences, Institute of Sport, Exercise & Health, UCL, London, WC1E 6B, UK. Electronic address: anna.marshall.17@ucl.ac.uk. Defence Medical Services, Lichfield, WS14 9PY, UK. Department of Surgical and Interventional Sciences, Institute of Sport, Exercise & Health, UCL, London, WC1E 6B, UK. Defence Medical Services, Lichfield, WS14 9PY, UK; Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK; Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, NE66 2NS, UK. Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK. Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK; Department of Cardiology, Poole Hospital NHS Foundation Trust, Poole, BH15 2JB, UK; Department of Postgraduate Medical Education, Bournemouth University, Bournemouth, BH1 3LT, UK.