His research activity is conducted, primarily, under the auspices of the MRC-ARUK Centre for Musculoskeletal Ageing Research at UoB and centres on skeletal muscle metabolism. Prior to this, Dr Breen completed a Post-Doctoral Research Fellowship at McMaster University, Canada, and a PhD at UoB. He is author of over 40 peer-reviewed articles and is regularly invited to speak at academic (ACSM, ECSS, ICST) and industry conferences (Dairy Council, Arla Nutrition, Nestle Healthcare). In addition, Dr Breen was recently elected as a Review Panel Member for the European College of Sport Science.