Gillian Russell asks whether we should all be climbing more trees and practicing our cartwheels? Fifty-something mum Jo Mosely describes the sheer joy she gets from doing headstands and talks about her passion for inspiring others to revisit childhood fun. Psychiatrist Prof Steve Peters explains what is happening to body and brain when we engage in simple, playful activities. Charlotte Roach talks about why she set up Rabble, a social community that keeps fit by playing fun games. Exercise physiologist Susan Dewhurst explains why playful, childlike activities can boost our fitness, health, balance and dexterity. Johanna Basford describes why she’s on a mission to make the world a happier place through the joy of colouring in. Cartwheel queens Alex, Susanne, Juliet and Nat share their experiences of revisiting childhood fun by attempting some cartwheels over the summer.