Currently Tiarnan is a final year medical student at the University of Limerick. In 2013, he graduated with a 1st class honours from the Bsc. Athletic Therapy and Training Programme in Dublin City University (DCU) and received the Academic Achievement Award upon graduation. After graduation he became a member of Athletic Rehabilitation Therapy Ireland (ARTI), and worked with Exwell Medical, a sports medicine clinic in Dublin, while also working with the DCU Sigerson Gaelic Football team. Since graduation he has also been carrying out research with DCU in the areas of hip and groin pain in elite Gaelic Footballers.

In 2015, Tiarnan founded and is currently President of the Orthopaedics, Sports & Exercise Medicine (OSEM UL) group at the University of Limerick, which currently has roughly a 150 members. This group aims to promote these disciplines within the University by providing educational talks and practical workshops. During his time at medical school Tiarnan has also developed a keen interest in emergency medicine and he was awarded a scholarship to study emergency medicine at the West China School of Medicine, in Sichuan University, China. While studying at Limerick, he has undertaken a number of Orthopaedic Electives and upon completion of his medical degree, he hope to pursue a career in Orthopaedic Surgery, while maintaining an interest in Sports and Exercise Medicine.