In 1997, The Spice Girls were the biggest phenomenon in the world of music. Their debut album, released in 1996, had been a No.1 best seller in 19 countries .
Melanie Chisholm, a.k.a. Sporty Spice, speaks to Tom Power about her new memoir, "The Sporty One: My Life as a Spice Girl," 25 years after the group skyrocketed her to fame.