Bruce Jenner infamously touted the fact that he ran a lot of miles in preparation for his gold medal-winning decathlon performance in the 1976 Summer Olympic Games.

Not to be outdone, Simon Pegg says he's run "lots" for his last two movies.

In "Hot Fuzz," the British comic actor starred as a physically fit police officer who was prone to chasing down criminals on foot. In his latest, the romantic comedy "Run Fatboy Run," Pegg plays an out-of-shape security guard who pledges to run a marathon to win back the woman he loves and to impress his young son.

Again, when discussing the films, Pegg stressed the words "running" and "lots."

"It's been an exhausting couple of movies. Probably more exhausting than anything I've ever done before, really," he said from Los Angeles, where he was helping promote his latest project.

"In fact, after all that running and exercising, I'm hoping to find a role in which I'm sitting down all the time," Pegg said joking. "Perhaps I could even replace Patrick Stewart in the 'X-Men' movies."

Still, he did note that "Run Fatboy Run" gave him "eight weeks to run an entire marathon, when most people do it in something like two hours, 20 minutes, or something ridiculous like that."

All his joking and pseudo-complaining aside, the 38-year-old actor is fairly trim. So, he says it was a challenge playing Dennis, a paunchy security guard who left his pregnant girlfriend, Libby (Thandie Newton), at the altar.

"I was coming off 'Hot Fuzz' and was in almost the best shape of my life," he recalled, noting that it took prosthetics to make him look "a little porky."

"There were three sets of bellies and rear ends — chubby, fat and really, really fat," he laughed. "I wanted to keep them around so I could play jokes on my friends that I don't see that much. 'Wow, you've really let yourself go,' they'd say."

Though he's gained cult status with the art-house hits "Shaun of the Dead" (2004) and "Hot Fuzz" (2007), Pegg is probably best-known to American audiences for a brief but memorable supporting role in 2006's "Mission: Impossible III."

That was one of the reasons why he agreed to star in "Run Fatboy Run." And after making a couple of movies — as well as a television show, "Spaced" — with his longtime friends, director Edgar Wright and actor Nick Frost, he was ready to go solo.

"I love those guys. They're my mates," he said. "But I do think it's best for our careers that we're not doing everything together. This afforded me that chance."

And the movie also allowed him to re-team with another friend, former "Friends" star David Schwimmer, with whom he worked on the 2006 film "Big Nothing." Schwimmer, who was already planning to direct "Run Fatboy Run," thought Pegg would be perfect as the lead.