PITTSBURGH (AP) -- Simon Biles and her coach Aimee Boorman don't talk about the pressure that comes with being a world champion.
They both know it's there, even if it's hard to tell while Biles is competing.
''She just goes out and does her thing,'' Boorman said.
And at the moment, no women's gymnast on the planet does her thing better than the springy 17-year-old who is still scratching at the surface of her considerable powers.
Biles sprinted to the lead at the U.S. Women's gymnastics championships on Thursday, putting on an impressive display as she closes in on a second straight national title. Her combined score of 61.60 through four nearly flawless events put her well ahead of second-place Maggie Nichols.
Yet as electric as she was at times while posting the best score on floor exercise, beam and vault, Biles wasn't perfect. Her workmanlike bars routine - always an issue - was stiff. She didn't really stick either landing on her two vaults. There was that one little wobble on the beam.
''There's room for improvements everywhere,'' Biles said.
An intimidating prospect for the rest of the small field this weekend - only eight women are competing in the two-day all-around - and the rest of the world, too. Barring catastrophe on Saturday, she will join the likes of Nastia Liukin, Jordyn Wieber and Shawn Johnson in the group of repeat national champions.
All three went on to win Olympic gold. It's a destination that looms in the distance for Biles, who is trying to do the unthinkable: remain atop her sport for two long years until the 2016 Games in Rio.
So far, so very, very good. Biles returned from a 10-month layoff after her triumph at the world championships last fall to win the Secret Classic in Chicago three weeks ago. The meet allowed her to smooth out the rough edges from a shoulder injury that forced her to take a well-deserved breather.
Consider her all the way back.
''This year she's coming in with not just a new attitude, but she's a year better trained,'' Boorman said. ''She has more confidence and experience under her belt.''
That experience turned the other gymnasts trying to earn a spot on the world championship team into a vanishing speck in her rearview mirror. Nichols trails Biles by a massive 3.15 points - the equivalent of a five-touchdown deficit in football - with Alyssa Baumann just behind Nichols in third.
Kyla Ross, who won gold at the London Olympics as part of the ''Fierce Five,'' was fourth after uncharacteristic errors on floor and uneven bars.
''I think this might be the toughest day,'' Ross said. ''I don't remember ever falling twice in a meet. This is frustrating.''
There were no concerns for Biles, who started on beam and moved along the 4-inch wide slab of wood 4 feet off the ground with the confidence of a teenager running roughshod at the mall. Her body landed with an emphatic ''thud'' each time she completed one of her intricate series of leaps and flips. A small wobble cost her but her score of 15.700 was more than a half-point better than anyone else.
And the margin just kept getting bigger. Biles is a 4-foot-9 bundle of kinetic energy, a physical marvel who doesn't jump so much as explode. Not the most graceful dancer, she makes up for it by turning her tumbling runs into 5-second tutorials on defying the laws of gravity.
Buoyed by an energetic crowd that included defending Olympic all-around champion and good friend Gabby Douglas - currently on the comeback trail herself - Biles was captivating. Then again, she figures that's what she's supposed to do.
''We're here to put on a show,'' she said.
Biles is currently hogging the marquee for an American women's program very much in flux. Injuries to several top newcomers, including Rachel Gowey, turned nationals into little more than a coronation for Biles.
Perhaps that's why her performance was so encouraging. On a night when she didn't have to be sharp, she was scintillating.
Call it a sign of maturity. Biles is learning to live with her role as the heavy favorite.
Biles certainly wore it well Thursday. She almost looked bored after drilling her Amanar vault - which packs 2.5 twists into two terrifying flips - and practically yawned during her follow-up attempt, a slightly less difficult version of the same vault.
By the time Biles ended the night on the uneven bars, she needed only to stay upright to take the lead into Saturday's finals. She didn't exactly sit on her advantage. Her 14.550 was only so-so. Considering she's the class of the world in just about everything else, she'll take it.