Mark is a 5 times European Championships 800m medalist – silver indoors in 2015, bronze indoors in 2019 & 2025 and bronze outdoors in 2014 & 2022. He won 15 National Championships titles in Ireland and holds the Irish 800m Records indoors (1:45.15) and outdoors (1:44.53).  He is a qualified medical doctor having studied at University College Dublin.