In a three-minute trial (and presumably in 800-meter races), the brain still calls for a sprint as the finish line approaches; the muscles are simply unable to obey. If you’re looking for the midpoint between the muscle’s role in hoisting a car and the brain’s role in running an ultra, this is as good a definition as any: that agonizing point, about 600 meters into an 800-meter race, where you’re holding nothing back but can feel yourself slowing anyway.
