An American import, Roller Derby is part race/part contact sport, in which young women violently jostle and elbow their opponents in an attempt to steer them off course.
Adopting alter-egos on the track characters like Anna Mosity, Grievous Bodily Charm, Vaga-blonde and Debbie does Malice don war paint, vibrantly-coloured costumes and roller skates as they skid, smash and knock into each other.
Leagues are currently springing up in cities across the UK with demand rapidly outstripping the number of places available.
These women often end up bruised and battered - so what has propelled the rise of this aggressive 'sports entertainment' amongst Britain's young women?
In this programme we explore the stories of two young skaters from the London Roller Girls - Auntie Terror, who skates in the main league, and Hannah Harding, who skates in the practice league.
Produced by Eleanor McDowall
A Falling Tree Production for BBC Radio 4.