First, there was Mary Lou Retton in 1984.

Then, there was Carly Patterson in 2004.

Now, gymnast Shawn Johnson has her sights set on becoming the 2008 all-around Olympic champion.

The 16-year-old from Des Moines, Iowa, enters the Beijing Games as the favorite to win all-around gold after claiming the 2007 world title. A victory in China would earn the U.S. just its third gold in the women's all-around competition, and would mark the first time in Olympic history that the U.S. has claimed back-to-back Olympic crowns.

The pressure is on the reigning two-time national champion, but Johnson isn't about to back down.

"I honestly don't know what it takes to be an Olympic champion, but I know if I work as hard as I can and if I go there and give it my all, then I know there is nothing else I could have done," Johnson said.

Johnson, who started gymnastics at age 3, got into the sport because her parents wanted to find a way for their youngster to wear off energy. They found an outlet for their daughter where she not only got to wear off her energy, but she was also able to showcase it.

Marta Karolyi, a former Romanian coach who is now the national team coordinator of the U.S. squad, was drawn to Johnson's energy the first time she saw a video clip of the young athlete.

When recalling the videotape Johnson's coaches, Liang Qiao (Chow) and Liwen Zhuang (Li), sent to her about three years ago, Karolyi said she was immediately impressed by the "bouncing" youngster and offered her an invite to the next national training camp.

It didn't take long for Johnson to soar to the top of the gymnastics ranks. In 2007, she won all-around gold at the world championships, the U.S. nationals, the Pan American championships and the American Cup.

"Last year was kind of a dream," Johnson said. "It just really motivated me to do even better this year and to accomplish my ultimate dream."

At the Beijing Games, Johnson will have to compete against the world's best, including Romania's Steliana Nistor, who was second at Worlds, Brazil's Jade Barbosa, who took bronze at Worlds, and hometown athletes Yang Yilin and Xiao Sha of China.

But the American teen isn't worried about her competition. Claiming that she thrives under pressure, Johnson is looking to have fun at the Olympics.

"I want to go out this year and have the time of my life," Johnson said.