While some celebrities claim they’re just ‘naturally thin’, Beyonce Knowles has admitted it’s hard work for her to stay in shape.

The singer/actress told Self magazine: “I’m not one of those people who doesn’t have to work at it. I can’t eat what I want, and I can’t not go to the gym.

“I’m trying to do as much cardio as I can, so if I have a really long day of dancing [in rehearsals], then I’ll run maybe three miles. If not, then I’ll run 6.”

“[Then] I’ll put on a song that I really like and do [biceps curls with] 5-pound weights [for] the whole song and just try to burn out.

“The truth is, it’s a lot of sacrifice. It’s more about your mental strength than physical strength. You have to push yourself. It doesn’t matter what trainer you have. And it doesn’t matter what program you’re on. You have to be healthy and make the right choices.”

And the “right choice” includes knowing when enough is enough: “To me, it’s sexier when it doesn’t look like you go to the gym. If you look like you’ve been spending a lot of time in the gym, then it just looks like you spend a lot of time in the gym.

“So I never want to get to that point where it’s not natural. I think it’s important to feel like a woman, as well as look like a woman.

“I feel best when I’m not really thin and not really heavy, like now, when I’m still curvy. I really believe that everyone is supposed to be different, and whatever is a natural weight for you is usually what looks best.”

She added while she has to “keep things in all the right places” to fit into her Thierry Mugler tour costumes, when she’s not performing or filming a movie, she relaxes her regime: “When I’m off, I feel like I’ve earned [the right] to eat what I want, and I give myself a certain amount of time.

“There’s too much good food out there to never indulge.”