The runner’s brain is a mystery. Researchers, engineers, doctors, trainers or “heads of performance” cut it into thin slices to find secrets. How do neurons command muscles? How do the muscles respond to them? How many watts does a desire to win produce? How does an emotion help accelerate in a pass? After NBA players or F1 pilots, Tour de France riders will one day invade the Wild West of neuroscience at full gallop. On applications, they will check, amazed, in figures and curves, the law respected for the moment especially by empiricism: it is the head which makes win.