Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance

by Alex Hutchinson

Similar belief effects can also show up with no pills in sight.

For example, surveys have found that the greater your interest in sports, the more superstitious you’re likely to be. Intrigued by all the tales of superstitious superathletes like Michael Jordan, who famously wore his old college shorts under his uniform throughout his professional career, German researcher Lynn Damisch of the University of Cologne set out to test whether lucky charms actually work. Sure enough, in one study, she found that simply saying “Here is your ball. So far it has turned out to be a lucky ball.” boosted golf putting performance by 33 percent compared to saying “This is the ball that everyone has used so far.”

So, yes, self-confidence can make you try harder—but it can also work in more subtle ways. Telling runners they look relaxed makes them burn measurably less energy to sustain the same pace.12 Giving rugby players a postgame debriefing that focuses on what they did right rather than what they did wrong has effects that continue to linger a full week later, when the positive-feedback group will have higher testosterone levels and perform better in the next game.13 Even doing a good deed—or simply imagining yourself doing

a good deed—can enhance your endurance by reinforcing your sense of agency: in one study, donating a dollar to charity enabled volunteers to hold up a five-pound weight for 20 percent longer than they otherwise could.14 Worryingly, they gained even more strength from imagining themselves doing an evil deed—confirmation, perhaps, of a theory, long discussed on online running message boards, that the best way to run an 800-meter race is fueled by “pure hate.”15

That lesson, he recalled, stuck with him—first as an athlete and later as a scientist: “You have to teach athletes, somewhere in their careers, that they can do more than they think they can.”