Is your skin too thick? Feminist, activist and founding leader of the Women's Equality Party Sophie Walker talks to Viv Groskop about coping with hostility and the value of being thin-skinned. She talks pacing, breathing, how fitness will help you rouse the rabble, how young women will inspire you - and why amid all the shouting you must remember the effect your words are having on the quiet ones. Viv's books, including How to Own the Room, are out now.