In this excerpt of their new book 'Peak Performance: Elevate Your Game, Avoid Burnout, and Thrive with the New Science of Succes,' Brad Stulberg and Steve Magness examine the importance of self-transcendence on and off the track.

It was the 2015 IAAF World Championships, and Ashton Eaton was dead tired. Eaton, as you may know, is a two-time Olympic champion decathlete who some say is the greatest athlete of all time. Still, he had his work cut out for him: In order to break the world record, he needed to run faster than 4 minutes and 18 seconds in the final event, the 1500 meters—a significant challenge in and of itself. But here’s the thing: Eaton had already completed the other nine events in the decathlon, and he had more or less locked up a gold medal. In other words, he was exhausted and had little to gain from going all out, especially because the record he would be trying to break was his own, set a few years prior.

Nevertheless, Eaton decided to go for it. Why, you might wonder? He told the media that when the pain came on, “I was just thinking, it’s not for me so I have to go.” When further questioned, Eaton said, 

“Really I was just thinking about me sitting on the couch when I was little and watching somebody like Michael Johnson or Carl Lewis jump and run, and that’s the reason I’m here today. I thought maybe there’s a kid on a couch somewhere and if I break this world record they may be inspired to do something.” 

He ran the 1500 in 4 minutes and 17 seconds.

The motivation Eaton described is a good example of the power of self-transcendence. In a paradoxical twist, the research suggests that the less we think about ourselves, the better we become. Self-transcendence not only allows us to overcome our greatest fears and break through our limits, but it also improves our performance in less heroic, everyday activities. In one study, researchers from the Wharton School at the University of Pennsylvania found that hospital janitors who cleaned bedpans and mopped floors performed better and reported higher levels of satisfaction when their job was framed as being integral to the healing of other people. The janitors were constantly reminded that by keeping the hospital clean, they were minimizing the chance of bacteria spreading and harming the already vulnerable patients. They no longer saw their job as just removing vomit from the floors; they saw it as saving lives. Some hospitals have even eliminated the job titles “janitor” and “custodian” in favor of titles like “health and safety team member” or “environmental health worker.”

Other research shows that college students working as phone solicitors asking alumni for donations improved their performance after a recent graduate spoke to them about how grateful he was for their work. This wasn’t just any graduate student, though; he had attended the university on scholarship dollars raised via the solicitation efforts of the students. In the month following this meeting, the student solicitors raised 171 percent more money.

These are just two of many examples that show how linking one’s work to a greater purpose enhances everyday performance, even on mundane tasks. Just ask yourself: Are you more likely to give something your all if you know doing so will benefit someone else or a greater cause? For almost every great performer in athletics, art, or at the office, the answer is more likely than not to be an enthusiastic yes.

Exercise science reveals some potential reasons self-transcendence is such a powerful motivator. Fatigue has both physical and psychological components. Samuele Marcora, PhD, the director of research at the University of Kent School of Sport and Exercise Sciences, believes that we constantly weigh our physical perceptions of effort associated with an activity (i.e., how hard something feels) against our motivation to do that activity. When perception of effort is greater than motivation, we slow down or ease up until the two are balanced. It follows that the more motivated we are, the greater the perception of effort we are willing to tolerate. According to Marcora, an athlete can improve her performance by either decreasing her perception of effort (i.e., training her body so that running 5-minute miles feels easier) or by increasing her motivation.

And when it comes to increasing motivation, a wide body of research suggests doing something for others is far more effective than traditional incentives like money or reputation. Perhaps this is why after unbelievable, record-breaking performances—ones that inevitably required enduring immense pain and suffering—athletes like Eaton never say they were thinking about how great it would feel to be a champion or how much money they would win. Rather, after crossing the finish line, they almost always report that when the pain came on, they began thinking about their family, their god, or their friend who has cancer. In other words, they were able to endure the pain, to say “more” when their bodies were screaming “less,” because they were supremely motivated by a self-transcending purpose.

Another great example of this is Meb Keflezighi, who, in 2014, became the first American to win the Boston Marathon in over 30 years. His historic win was extra special because it occurred just 1 year after the horrific terrorist attack at the 2013 race. Keflezighi credits his incredible performance to the inspiration he felt while running for those who had died in the terrorist attack the year before (known as the Boston Bombing). He even wrote their names on his race bib. Representing both the victims of the prior year’s attack, but also as the top American in the race, he ran with greater purpose and motivation.

“Toward the end I was remembering the victims who passed away,” he said. “They helped carry me through.”

While Marcora’s research and the examples of Eaton and Keflezighi are in the realm of athletics, it’s easy to see this theory come to life in other arenas, too. By linking their work to a greater purpose, for example, the hospital janitors and student solicitors increased their motivation in a big way. As a result, they were able to tolerate a greater perceived effort on the job, whether this meant cleaning more arduously or calling more alumni with heightened focus and engagement. Ultimately, they performed better.

Purpose fosters motivation; motivation lets us endure a greater perception of effort; and enduring a greater perception of effort often results in better performance. This equation holds true in every field—from the track to the workplace. A greater-than-self purpose not only makes the world a better place, it makes you a better you.

Excerpted from Peak Performance: Elevate Your Game, Avoid Burnout, and Thrive with the New Science of Success by Brad Stulberg and Steve Magness. By permission of Rodale Books. This piece was previously published on NYMAG: The Science of US.