What Does It Take To Keep Going In The Toughest Terrain?

From the time of Hippocrates, the limits of human exertion were thought to reside in the muscles.

- Vaibhav Raghunandan

This hypothesis was established in the Nobel Prize-winning work of A.V. Hill in 1922. The theory is simple: working muscles when pushed to their limit accumulated lactic acid. When concentrations of lactic acid reached a certain level, the muscles could not function. “Muscles contain an automatic brake, carefully adjusted by nature,” Hill wrote. It’s a theory that stands.

Ask an endurance athlete about this and they will always point towards the brake in the mind. Ask Milind Soman, the posterman of running, and he will talk about conquering the mind before conquering the body. And, to a certain extent—through a convoluted way—science has his back.

In 1999, three physiologists from the University of Cape Town Medical School put a group of cyclists to the test to establish the link between neurological control and athletic prowess. They worked themselves to exhaustion through a 62-mile lab ride that was measured via electrodes. And, the percentage of leg muscles they were using was at fatigue limit. Standard theory dictated that the body would recruit more muscle fibres as it approached exhaustion—a compensation for tired and weakening muscles.

Instead, the opposite happened. As the riders approached complete fatigue, the percentage of active muscle fibres decreased, till they were only using about 30 percent. Even as they felt they were giving their all, the reality was quite the opposite. The brain was purposely holding back the body.

Through the test, Timothy Noakes, head of the research group, concluded that the body had a central governor: a neural system that monitors carbohydrate stores, levels of oxygen in the blood, rates of heat gain and loss, and work rates. The governor’s job was to hold our bodies back from the brink of collapse by creating painful sensations.