The E! News anchor said that she and husband Bill would train together for the athletic event in order to be prepared for the physical strain.
"I really want to run in a marathon this year," she told TooFab.
"Bill has run two marathons, and I've run half a marathon, so I always go around gloating, 'Oh, I've run a marathon', and Bill's like 'A half-a-marathon, honey!' So Bill and I are going to train. He's going to train me, and we're going to run a full marathon together."
Bill also revealed his own goals for 2011, saying: "I'm going to learn Italian. I want to be able to speak Italian fluently by the end of 2011.
"Her parents are always talking about me [in Italian] and I have no idea what they're saying at the dinner table!"