“X-Factor” judges L.A. Reid and Simon Cowell are in a fitness battle before the launch of the Fox show next month. The stocky Epic Records chief has signed up for daily five-mile runs and cut the wine, carbs and his expensive cigars. “L.A. got a glimpse of the grueling schedule during auditions,” a show insider said. “It’s a six-day-a-week job, especially during the live shows. It’s very different to what he’s used to, and being on screen isn’t forgving.” Cowell passed along his favorite recipes to Reid.