By GINA KOLATA

It is one of the secrets of elite athletes: to keep going at a level of effort that seems impossible to maintain. 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 Sports doctors say that, at the very least, most people could do a lot better if they knew what it took .

“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. Nothing could be further from the truth. And as athletes improve “it never gets any easier,” Dr. Swart said. “You hurt just as much.”

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.

Then Dr. Swart and his colleagues asked the cyclists to ride the course with all-out effort, but withheld information about how far they’d gone and how far they had to go. Subconsciously, the cyclists held back the most in this attempt .

That is why elite runners will examine a course, running it before they race it. “You are learning exactly how to pace yourself,” Dr. Swart said. Another performance trick is association, the act of concentrating intensely on the very act of running or cycling, said John S. Raglin, a sports psychologist at Indiana University.

In studies of college runners, he found that less accomplished athletes tended to dissociate, to think of something other than their running to distract themselves. “Sometimes dissociation allows runners to speed up, because they are not attending to their pain and effort,” he said.

“But what often happens is they hit a sort of physiological wall that forces them to slow down, so they end up racing inefficiently in a sort of oscillating pace.” But association, Dr. Raglin says, is difficult .

Dr. Swart says he sees that in cycling, too. “Our hypothesis is that elite athletes are able to motivate themselves continuously and are able to run the gantlet between pushing too hard ? and failing to finish ? and underperforming,” Dr. Swart said.

Athletes must resist the feeling that they are too tired . Instead, they have to concentrate on increasing the intensity of their effort. Kim Smith, an elite runner from New Zealand, did not attribute her success entirely to talent. “You have to be talented, and you have to have the ability to push yourself through pain,” she said.