In the first episode of a new series, Marie Crowe chats to Sonia O'Sullivan about her development as an athlete, how she became one of the best middle distance runners in the world and how she coped with setbacks.

CJ Stander on doing a job and doing it well

How do sportspeople develop into elite athletes? Each week RTÉ Sport’s Marie Crowe speaks to a sporting icon, tracing their journey from childhood in the hope of finding out how they became heroes.