ROME — Olympic marathon champion Stefano Baldini has a stress fracture in his left leg and will miss a month of training, slowing his bid to defend his crown.

Medical tests on Thursday revealed the fracture, which occurred during the London marathon on April 13.

Baldini finished 12th in the London race and is intent on defending his Olympic title in Beijing in August.

"I had just gotten over the disappointment from the (London) result and now I've got another problem," Baldini was quoted as saying on the Italian athletics federation Web site. "Being injured is not the best way to approach the games."