Muscle Men is season one of Extreme, the BBC podcast that knows no limits. Each action-packed season tells the story of people who've pushed themselves to the very edge of what's physically or mentally possible - and in doing so, have changed the world...

1980s Los Angeles. A young, amateur bodybuilder named William Dillon comes to California in search of the supersized American dream - to get absolutely jacked. But beneath the smell of sweat, pulsing disco beats, and the rhythmic clank of weights, there's a secret. Many of the bodybuilders and gym rats he meets are using steroids to achieve their pumped up physique. And if that's what it takes to make it big, Dillon's willing to do it too. But not only that, he's smart. He recognises there's money to be made from selling the promise that you can get ripped, quick. Dillon, along with the cult hero of the steroid underground - the 'steroid guru' Dan Duchaine - and David Jenkins, a Scottish Olympic medallist with a nose for business, will launch the largest illegal steroid dealing ring the USA had ever seen. As steroid use grips small-town gym-goers, pro bodybuilders and elite athletes, the cops, legislators and the world of international sport scrambles to crack down. Historian, podcaster and fitness expert Natalia Mehlman Petrzela, presenter of hit podcast Welcome To Your Fantasy, reveals how the rise of America's fitness and gym-culture through the 20th century collided with the unregulated availability of steroids in the 1980s, transforming the way we see our bodies, and the lengths to which we'll go to in the pursuit of perfection.

Presenter and Executive Producer: Natalia Mehlman Petrzela Producer: Caroline Thornham Assistant Producer: Mo Ahmed Editor: Katherine Godfrey Production Manager: Cheree Houston Sound Design and Mix by Nicholas Alexander and Daniel Kempson Original Music by SilverHawk Executive Producer: Max O'Brien Commissioning Editor: Dan Clarke A Novel production for BBC Radio 4