To prepare for a walk that served as a high school physical education exam, he asked his brother Fabián to train for one week next to the group of athletes directed by trainer Luis Muñoz.

With few weeks of preparation he won the race AID, winning the right of representing Ecuador in New York City and London as a sport ambassador.

Two years later, he won the Junior World title in Seoul, Korea, followed shortly by victories in South American and Pan-American open competitions.

Following his win he embarked on a 459 km (285 mi) pilgrimage, walking, jogging and running from Quito's Franciscan cathedral to his hometown of Cuenca.

Pérez's winning time of 1:17:21 in 2003 became the first official world record for the 20 km walk when standards for road events were recognised from 2004 onwards and he received a financial bonus.