Ludacris admits he's a ''gym rat''.

The 40-year-old rap star has revealed he's obsessive about his fitness regime, saying he works out six days a week in order to stay in good shape.

He shared: ''I am a gym rat myself. I work out like six days a week with two different trainers.''

Ludacris - whose real name is Christopher Bridges - is known for his energetic on-stage performances, and the rapper admitted he takes his live shows very seriously.

Speaking to Billboard, he explained: ''Stage performance is extremely important to me and that whole moving the crowd thing, I just take it really seriously.

''I feel like all the time it's paid off because it kind of reigns throughout the industry ... that we literally are the ones who go above and beyond what is asked of us onstage. That word of mouth gets around from different audiences, not only in the country, but around the world.

''That's kind of what keeps me motivated and inspired to make sure I always give an energetic performance. It's really just internal, man. Just making sure that I never forget that I'm living out my dream, loving what I'm doing. I think that's it.''

Asked which other rappers have a similarly great stage presence, he added: ''I would say before me, Busta Rhymes. That's a hard question because, no disrespect to anybody, but I can't think of anyone that is that ... actually, I'll say Rae Sremmurd.

''They remind me a lot of the energy that I possess. I love how they go out and give a crazy good time.''