Sheryl Crow's ex-fiance Lance Armstrong is struggling with his bid to complete the New York Marathon - and he's beginning to think it was a bad idea. The Tour De France champion plans to join celebrities like The Streets' MIKE SKINNER for the 26-mile run in November (06), but he admits training is much harder than he initially anticipated. Armstrong says, "It's painful. Running is totally different from cycling - the impact on the body. "Those guys (marathon runners) train hard, watch what they eat and go to bed early - things I don't want to do anymore. I'm over that. I like to have a bit of fun." Armstrong has been given a celebrity boost as he trains in Los Angeles - Matthew Mcconaughey and Jake Gyllenhaal are helping the retired cycling star get in supershape for the marathon.