EUGENE, Ore. -- They are called the Olympic trials.

But a more apt name would be the Olympic Trials and Tribulations.

America’s potential Olympians have been running, jumping, throwing, diving, swimming, flipping and twisting over the past week to try to win a precious spot on the team going to London for the July 27-Aug. 12 Summer Games.

It’s tough to make the roster of the country that won the medal count at the 2008 Beijing Games and is attempting to regain supremacy in the gold medal count, which it lost to mighty China four years ago.

In the major trials of track and field, swimming and gymnastics, the qualifying format is unforgiving. If an athlete trips over a hurdle, falls off the balance beam or gets out-touched at the wall after four years of training and dreaming — too bad. Perform or go home. Only the top three finishers in individual events make the track team. Only the top two in swimming. In gymnastics, there’s only room for five men and five women.

At Hayward Field at the University of Oregon, triumph and despair were on stark display. Olympic decathlon champion Bryan Clay crashed in the 110-meter hurdles, then fouled out of the discus. His quest to defend his 2008 gold medal ended in tears while young Ashton Eaton set a world record with his scintillating finish in the final event, the 1,500 meters, as the crowd went wild for the Bend, Ore., homeboy. Clay was already an afterthought.

One runner failed to advance to the final of the women’s 400 hurdles, and as she walked off the track, she stopped, knelt down and sobbed. She walked 20 yards and collapsed again, her legs wobbly from exertion and disappointment. She continued in this way, overwhelmed by the finality of her loss, and her sobs grew louder as she murmured, “No, no, no.” Observers felt sympathy, but she was alone with her thoughts.

Others were out-leaned at the finish line. Food poisoning weakened a bunch of athletes who ate salmon at the main hotel. Too bad. Fort Lauderdale’s Walter Dix was afflicted with a recurrence of a hamstring injury, finished last in the 100 meters and scratched from the 200 meters. Four years after he won double bronze and ignited hopes that he would challenge Usain Bolt, Dix had missed his chance to compete on his sport’s biggest stage.

Four years is a long time to wait.

For Miami’s Danell Leyva and his coach, stepfather Yin Alvarez, the time is now.

When Leyva was a toddler, he left Cuba with his mother and stepfather, who had defected from the Cuban gymnastics team. Seventeen years later, Leyva is realizing his vision and that of his parents.

He flew breathtakingly high on the high bar and won the trials in San Jose, Calif., by .50 over John Orozco. Leyva, all-around national champ and world parallel bars champ in 2011, has a checklist of goals on the wall of Alvarez’s Kendall gym. Olympic medals for himself and the U.S. men’s team are on the list.

Jordyn Wieber will go for trials gold Sunday, and unless she misses on her beautiful Amanar vault, no one is likely to beat her. Wieber, defending world champion, is next in line to inherit the tiara worn by Mary Lou Retton, Shannon Miller and Nastia Liukin. Gabby Douglas, the effervescent “flying squirrel,” is stealing the show, however.

The U.S. women’s “Magnificent Five” plans to take the team gold back from China, which competed with underage girls in 2008.