“The mentality was I will do whatever it takes to win,” he added. “I was totally willing to have the worst pain. I was totally willing to do whatever it takes to win the race.”

But the question is, how do they do it? Can you train yourself to run, cycle, swim or do another sport at the edge of your body’s limits, or is that something that a few are born with, part of what makes them elites?

Sports doctors who have looked into the question say that, at the very least, most people could do a lot better if they knew what it took to do their best.

“Absolutely,” said Dr. Jeroen Swart, a sports medicine physician, exercise physiologist and champion cross-country mountain biker who works at the Sports Science Institute of South Africa.

“Some think elite athletes have an easy time of it,” Dr. Swart said in a telephone interview. Nothing could be further from the truth.

And as athletes improve  getting faster and beating their own records  “it never gets any easier,” Dr. Swart said. “You hurt just as much.”

Image Credit... Ian Walton/Getty Images

But, he added, “Knowing how to accept that allows people to improve their performance.”

One trick is to try a course before racing it. In one study, Dr. Swart told trained cyclists to ride as hard as they could over a 40-kilometer course. The more familiar they got with the course, the faster they rode, even though  to their minds  it felt as if they were putting out maximal effort on every attempt.