INDIANAPOLIS — It just wasn't Bryan Clay's day.

Being a champion athlete — as Clay was after winning the decathlon at the IAAF World Championships in Helsinki last August — is often a delicate tightrope trip between supreme conditioning and supreme risk, of illness and injury.

Clay, a 1998 Castle High and 2002 Azusa Pacific College graduate, fell off the tightrope yesterday.

Bidding for a third consecutive title in the decathlon at the USA Outdoor Track and Field Championships, the 26-year-old's day began to fall apart in the pole vault, the eighth of the 10 events in the decathlon.

Three consecutive misses at 15 feet, 5 inches spelled the end. On his third trip down the runway, Clay simply ran under the bar.

He was ill to begin with — still subpar after a demanding first-day performance that saw him holding the lead through five events with a score of 4,394 points, but at a physical cost. He had to be carried off the track to the medical tent after winning Friday's final event, the 400 meters.

Clay still managed to finish fourth in the 110-meter hurdles in 14.34 seconds, and won the discus with a throw of 167-6 yesterday morning. But the pole vault was next and he was done. He scratched from the last two events, the javelin throw and 1,500-meter run, leaving the event to his principal rival and 2004 Olympic teammate, Tom Pappas, who went on to win with 8,319 points.

"This is more frustrating than disappointing," Clay said. "I'd much rather give up my title after the 1,500 meters than like this."

Clay had said he was "OK" after Friday's competition, vowing to soldier on.

In truth, though, he wasn't.

"I really felt dehydrated (Friday) and nearly passed out after the 400 meters," he said yesterday. "I got IVs and the doctor said I was hypoglycemic (having low blood sugar). My legs didn't feel well in the hurdles and my discus wasn't very good, and I just didn't have it in the pole vault."

With both Clay and 2005 NCAA champion Troy Hardee of Texas both out — Hardee also had a no height in the vault — the event became a romp for Pappas.

The former Tennessee star, who'd endured his own series of disappointments — including knee, foot and shoulder injuries that knocked him out of the 2004 Athens Olympic event — stayed on his feet this time and added the 2006 U.S. titles to the ones he won in 2000, 2002 and 2003.

Pappas' second-day performances consisted of a 14.32 high hurdles, a 63-4 discus throw, a 16-8 pole vault, a 182-8 javelin throw, and a 4:59.50 1,500.

For Clay, whose career-best total remains the 8,732 points he amassed while winning the gold in Helsinki, where and when he'll be able to return to competition remains pure speculation.

"I'll probably be OK again in maybe two weeks," he said. "But then we'll just have to see. I'll need some time to decide."

If it's any consolation, the history of the decathlon is littered with shattered dreams.

Dan O'Brien's no-heighting the pole vault at the 1992 Trials knocked him out of the Barcelona Olympics. Pappas couldn't make it through the 2004 Athens Games. And Rafer Johnson, Dave Johnson and many other decathlon stars endured major setbacks.

Clay himself was unable to finish the World Championships of 2001 and 2003.

If Clay needs additional consolation, it's the knowledge that this may be the year to take an early break. It's the one year in four with no Olympic or World Championship meets on the agenda.

The World Cup, in Athens on Sept. 16 and 17, is the big event of the 2006 season but is basically an international team competition that does not include the decathlon.