Steve Cotter didn't invent kettlebells, but it's impossible to talk about their popularity in the Western world without mentioning his name. Since the early 2000s, he's given over 600 seminars and presentations on kettlebell training, in addition to authoring books and producing countless videos for everyone from beginners to competitive athletes. We talk with the coach and IKFF founder about the rise of kettlebells and what so many of us miss about the mental aspect of training.