Instead, over the past thirty years, in the world of action and adventure sports, in situations where asses really were on the line, the bounds of the possible have been pushed further and faster than ever before in history. We've seen near-exponential growth in ultimate human performance, which is both hyperbolic paradox and considerable mystery. Somehow, a generation's worth of iconoclastic misfits have rewritten the rules of the feasible, not just raising the bar but often obliterating it altogether. And this brings up one final question: Where-if anywhere-do our actual limits lie?