From the New York Times
How to Push Past the Pain, as the Champions Do

By GINA KOLATA Published: October 18, 2010
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, leaving some energy in reserve.
That is why elite runners will examine a course, running it before they race it. That is why Lance Armstrong trained for the grueling Tour de France stage on l’Alpe d’Huez by riding up the mountain over and over again.