Olympic gymnast Paul Hamm announced his retirement on Tuesday, just four months to the day before the 2012 London Olympics, because his body couldn't handle training anymore, according to The Associated Press.

Hamm, who became the first American male gymnast to ever win a world or Olympic all-around title-he did both-arguably singlehandedly put men's gymnastics in the United States on the global map. He helped lead the U.S. team to its first Olympic silver medal in 20 years in 2004 and was an integral part of the 2001 and 2003 American world championship teams that also won silver.

Hamm's Olympic career is a storied and turbulent one, which includes a judging controversy in 2004 and an injury that kept him from competing in 2008. Hamm hoped that a comeback in 2012 would allow him a strong performance to cap off his Olympic career, but his retirement announcement, just four months before the London Olympic Games, proved that the comeback wouldn't happen.

It's come to that time, said Hamm to The AP. Your mind wants an outcome a certain way, and it used to be a certain way, but you can't get your body to perform that certain way. And I can see it.

Hamm has been no stranger to injury. In 2008, he broke a bone in his right hand at the U.S. championships, just 11 weeks before the Beijing Olympics. He earned a spot on the Olympic team, but he broke his right hand, which, along with an injured left shoulder that he suffered while recovering from the hand injury, forced him to withdraw a few weeks before the games.

Hamm returned to gymnastics in 2010, but, in January 2011, Hamm suffered a torn right labrum and rotator cuff and had surgery. However, he said he continues to be bothered by shoulder problems because of the surgery, and, as a result, any hopes he had of a comeback became futile.

I'm able to just look back at the gymnastics and the performance and remember it for a great thing, he said. I understand the things that happened in my life, it's just a part of the whole story. But overall, I feel the journey I had in the sport of gymnastics was a tremendous journey and very productive for me and my life, and the person I've become.

Hamm, who turns 30 in September, said he can still do gymnastics, but he is already noticing structural issues with his shoulder. He fears the damage the next few months of training could do.

I do have to worry about my body, he said. This is the body I have to carry with me the rest of my life, and hopefully it'll be useful.