John was awarded a 1st class BSc in Sports Science from the University of Wales, Bangor in 2002. In January 2003 he began working as a research assistant at the Olympic Medical Institute, Northwick Park Hospital, where he started his PhD research into the prevalence, diagnosis and treatment of exercise induced asthma in elite athletes. In May 2004 John was appointed as a Research Physiologist for the English Institute of Sport, where he continued to investigate respiratory problems in elite athletes. During this time John was the first researcher to screen the entire Team GB squad for exercise induced asthma prior to the 2004 Athens Summer Olympic Games, 2006 Vancouver Winter Olympic Games and the 2008 Beijing Summer Olympic Games. John was awarded his PhD from Brunel University in March 2006. He has been a BASES accredited Sport and Exercise Physiologist since 2006.
In 2007 John decided to take a research break and worked as an Acquisitions Editor for Human Kinetics, where he commissioned 30 Sports Science and Sports Medicine books. During this time John was also an honorary research fellow at Leeds Metropolitan University where he continued to test elite athletes for respiratory problems. From 2008, John has been an UK Sport advisor for asthma diagnosis in elite athletes.
In January 2010, John was appointed a Post Doctorial Research Fellow, at the Research Institute for Sport and Exercise. In this role John is leading a WADA funded research project investigating the pharmokinetic and performance enhancing effects of salbutamol in athletes.
In August 2012, John joined the School of Sport and Exercise Science at the University of Kent as a Lecturer in Sport and Exercise Science. He teaches on exercise physiology modules ranging from basics anatomy and physiology through to specialised issues in athletes. He is also running the Respiratory Clinic, which provides services to individuals with respiratory problems such as exercise induced asthma or dysfunctional breathing.