As laboratory demonstrations of the brain’s role in endurance have accumulated, the sports world has begun its own experiments. In May, Red Bull brought four élite cyclists and triathletes and two dozen researchers, led by a team of neuroscientists from Weill Cornell Medical College and Burke Medical Research Institute, in New York, to its Santa Monica headquarters. There they explored the endurance-boosting potential of transcranial direct-current stimulation, the technique used in the Brazilian study. Members of the U.S. national BMX team are testing a program that was developed by neuroscientists at the University of California, San Diego, to encourage mindfulness. Marcora, meanwhile, is in discussion with Recon Instruments, which bills its Recon Jet as “the first heads-up display for sports”—a Google Glass-like contraption that is ideal for flashing subliminal encouragement.
Of course, coaches and athletes have long known to focus their efforts on the brain. I contacted Steve Magness, a cross-country coach at the University of Houston and the author of “The Science of Running: How to Find Your Limit and Train to Maximize Your Performance,” to ask him about Marcora’s study. It was the eve of the N.C.A.A. championships, and he was at a hotel in Indiana. “It’s intriguing that a seemingly subliminal cue could impact performance,” he told me in an e-mail. But he wasn’t surprised. “That’s what coaching is all about.” For months, Magness had been preparing his runners for the critical point in a race, the moment at which fatigue threatens to eclipse motivation. He planned to look his star runner in the eye the next morning and tell him that he was ready for the challenge. “That reinforcement from a coach, if it is genuine, I’m sure has a bigger psychological effect both consciously and subconsciously than presenting smiley faces,” he said.