EUGENE, Ore. (AP) Hardly even looking the least bit exhausted, Galen Rupp gave a thumbs-up sign to the crowd before crossing the finish line.
Really, though, the last few weeks have left him thoroughly drained.
Rupp easily won his seventh straight 10,000-meter title at the U.S. championships Thursday night amid allegations that coach Alberto Salazar encouraged him and others to skirt anti-doping rules.
For 28 minutes, 11.61 seconds on a sweltering evening, Rupp had nothing on his mind but racing. Afterward, the questions began concerning the allegations that have triggered the U.S. Anti-Doping Agency to launch an investigation.
''It's been hard. I'm not going to lie. It's been difficult to focus,'' Rupp said. ''I believe in clean sport. I believe the truth will prevail.''
Rupp found himself at the center of a controversy after a story by ProPublica and BBC earlier this month contained contentions from former Salazar assistant Steve Magness and a former Salazar runner, Kara Goucher, that the coach circumvented the rules. Salazar responded on the eve of nationals by publishing a 12,000-word letter online disputing the allegations, saying the Oregon Project he leads ''will never permit doping.''
''I stand behind him 100 percent,'' said Rupp, who will also run the 5,000 on Sunday. ''The statement came out yesterday and I was thrilled with it.''
There was no catching Rupp as he pulled away from the field with around two laps remaining. He beat runner-up Ben True by nearly three seconds, the crowd giving Rupp a warm reception on the home stretch. Rupp rose to prominence at Hayward Field as a member of the Oregon Ducks.
That's why he gave the thumbs up, he explained. Salazar was by his side after he finished.
''In the end, I know the truth,'' Rupp said. ''Got to take a step back sometimes and look at everything. I'm ready to race. I'm not going to let anything get in the way of that.''
Another of Salazar's runners, two-time Olympic champion Mo Farah, was caught up in the aftermath of the BBC story. The British runner, not implicated in any of the allegations, routinely trained with Rupp, who would like to see the running relationship continue.
''We have a great thing going,'' Rupp said. ''We know we do things the right way. That's all I have to say.''
In the 100 meters, Tyson Gay overcame his nerves in advancing through the first round. The 32-year-old Gay was second in his heat behind training partner Remontay McClain, one of the new faces to burst on the scene.
McClain finished in 9.82 seconds to hold off Gay, who's still rounding back into shape after returning last summer from a one-year suspension for doping.
''I'm trying to get used to new faces,'' Gay said. ''It's a different era for me.''
He knows McClain well, training with him and all. Gay will soon get to know Trayvon Bromell well, too, since the sprinter from Baylor keeps flying down the track. Bromell posted the second fastest time of the night.
Taking all the action in from the sideline was Justin Gatlin, who's saving his energy for the 200 since he already has an automatic bye into the world championships in the 100 courtesy of his Diamond League title last season.
Gay wasn't sure how he would be treated in light of his doping offense. He received a one-year ban that started June 23, 2013, for testing positive for steroid precursor DHEA - a penalty that was reduced after he provided information that led to USADA's case against his former coach, Jon Drummond. Gay, the American record-holder in the 100, also accepted a loss of results dating to July 15, 2012, which included the 4x100 relay team being stripped of its silver medal from the London Olympics.
When his name was announced, Gay received some cheers.
''When you're honest and man up to the mistakes you've made, I believe they forgive you,'' Gay said.
Carmelita Jeter had the top time in the women's 100, finishing in 10.87 seconds, which was just barely ahead of Jasmine Todd. Jeter is working her way back from a quadriceps injury.
Some things to know from the opening night of nationals:
WHAT TIME IS IT?: Molly Huddle kept checking her watch on her way to a win in the women's 10,000. And no, she didn't have somewhere else to be. ''I wanted to keep a good pace, stay in that zone,'' she explained.
FASHION FIRST: Even in the hot weather, Sanya Richards-Ross still wore her trademark sleeves in the first-round of the 400. ''They're my thing, so I have to wear them,'' laughed Richards-Ross, who won her heat in 51.93 seconds.
GOOD START: Two-time world champ Trey Hardee is in second place after the first day of the decathlon, trailing Jeremy Taiwo by 78 points. ''I'm in great shape. I'm healthy. But I'm not sharp,'' Hardee said. Ashton Eaton has an automatic bye into worlds being the defending champ. He competed in the long jump.
QUITE A LEAP: First the NCAA title, now a national crown. It's been quite a month for University of Florida long jumper Marquis Dendy. His winning jump was 28 feet, 5 3/4 inches.