In this series of special editions of BBC Radio 4 podcast Just One Thing, Michael Mosley quizzes the world’s leading health experts on the best ways to live well. In this Exercise Special, we hear from Marie Murphy – Professor of Exercise and Health at Ulster University and leading expert in physical fitness and lead scientist advising on the UK physical activity guidelines. We hear the top tips that Professor Murphy swears by to get maximum fitness for minimum effort. Could exercising in short bouts be better for you? Why should we all be building muscle over 30? And could the way you walk change your life? And as this is a Just One Thing special, Michael ends the interview by asking Professor Murphy for the single most effective health hack for keeping in shape. Series Producer: Dom Byrne Production Manager: Maria Simons Exec Producer: Zoe Heron Specially composed music by Richard Atkinson (Mcasso) A BBC Studios production for BBC Sounds / BBC Radio 4.