You’ve felt it. The moment your body says stop. Your legs leaden, lungs burning, every instinct telling you there’s nothing left. But what if that signal isn’t the end of your capacity? What if it’s just your brain playing it safe?

In Endure, award-winning science journalist and elite distance runner Alex Hutchinson upends everything we think we know about human limits. Drawing on decades of research and the cutting edge of sports science, he makes a compelling, evidence-backed case: fatigue is not a physical event. It is a sensation, one manufactured and managed by the brain, which is constantly calculating how much you have left and deciding, often conservatively, when to call it.

This changes everything. Because if your limits are partly a decision rather than a fixed ceiling, they can be negotiated. Trained. Pushed.

Hutchinson takes us from early experiments with electrical currents and frogs’ legs to sophisticated brain imaging,