Olympic champion Nastia Liukin ran out of time.

Liukin withdrew her name from consideration for the world gymnastics championships Monday, saying she hasn't had enough time to train. Liukin, only the third U.S. woman to win the Olympic title, has been in high demand for appearances, photo shoots and commercial opportunities since she left Beijing, but the schedule wreaked havoc on her training.

The first of two training camps that will be used to choose the U.S. women's team is next week, and worlds are Oct. 13-18 in London. There is no team competition at this year's worlds, only the all-around and individual events.

"I didn't want to go out there and compete and represent Team USA if I wasn't at my best," Liukin said. "Physically, I'm not capable of doing it because I didn't have enough time to prepare."

While Liukin said she is going to take a break from the sport _ "I hope to go on vacation, hopefully on an island somewhere" _ she insists she is not retiring.

She plans to return to the gym, and still hopes to compete at the London Olympics in 2012. She'd also like to compete at another world championships. Liukin has won nine medals at worlds, tying her with Shannon Miller for most by a U.S. gymnast.

"This decision has absolutely nothing to do with the rest of my career. It's based on just this year, the world championships," Liukin said. "I really feel like it was necessary just because I haven't really had much time off. I wasn't always in the gym, but I was always on the go.

"I'm going to take some time off, regroup, get ready for the next few years and decide what the plan is from here on out."

Making this decision was stressful, Liukin said, because she didn't want to let anyone down. Though there's no team competition at worlds, these championships set the tone for the leadup to the next Olympics and give an early indication of who are the teams and gymnasts to watch.

The Americans served notice they had rebounded from their disappointing showing in Sydney by winning two of the four event titles at the 2002 world championships. Chellsie Memmel and Liukin were 1-2 in the all-around in 2005, and the Americans went on to collect seven more medals in the event finals. Liukin took gold on beam and bars.

Liukin said she talked with her parents _ father Valeri is her coach _ over the weekend, and spent two days trying to track down women's national team coordinator Martha Karolyi, who is in Romania on vacation. When she finally got ahold of Karolyi on Monday morning, Liukin said it was one of the hardest conversations she's ever had.

"She definitely tried to convince me to come to camp and give it one more shot," Liukin said. "I could tell it was a little hard for her to take, but it hasn't been easy. At same time, this is the right decision for me at this time."

Liukin's decision will give Karolyi some flexibility in selecting a team for worlds. Countries can send only four gymnasts, and are limited to two gymnasts per event. Liukin would have done, at most, balance beam and uneven bars.

"We appreciate her making a decision that is right for her, as well as putting the goals of her teammates ahead of her own," Karolyi said. "We look forward to working with Nastia as she returns to competitive gymnastics when she is ready."

Liukin's announcement wasn't a complete surprise.

She's crisscrossed the country since winning gold in Beijing, doing everything from appearing at Fashion Week to picking up the female athlete of the year award at the ESPYs. She's loved all the experiences, but gymnastics is not a sport that can be done on a part-time basis.

It takes hundreds of repetitions to perfect a routine _ even routines she was doing with ease just last summer. Liukin would feel as if she was making progress after a few days at home, only to leave for a few days and then feel as if she had to start the whole process over again when she returned.

"It was very frustrating," she said.

Liukin curtailed her schedule a few months ago so she could compete at the U.S. championships, which were in her hometown of Dallas. She did one event, finishing fourth on beam, but the solid yet imperfect performance showed she wasn't back to top level yet.

And that's not good enough.

As the Olympic champion, the expectations are higher for Liukin. She not only accepts that, she expects even more of herself. If she's not ready to contend for a gold medal, then she's not ready to compete.

"I've set my standards too high," she said. "I don't want to just go out there and compete."