The capacity to endure is the key trait that underlies great performance in virtually every field. But what if we all can go farther, push harder, and achieve more than we think we’re capable of?

Blending cutting-edge science and gripping storytelling in the spirit of Malcolm Gladwell—who contributes the book’s foreword—award-winning journalist Alex Hutchinson reveals that a wave of paradigm-altering research over the past decade suggests the seemingly physical barriers you encounter as set as much by your brain as by your body. This means the mind is the new frontier of endurance—and that the horizons of performance are much more elastic than we once thought.

But, of course, it’s not “all in your head.” For each of the physical limits that Hutchinson explores—pain, muscle, oxygen, heat, thirst, fuel—he carefully disentangles the delicate interplay of mind and body by telling the riveting stories of men and women who’ve pushed their own limits in extraordinary ways.