Catherine Zeta-Jones stays slim by hula-hooping and swimming every day.

The 43-year-old 'Playing For Keeps' star has opened up about her dedicated fitness routine and claims she doesn't need any professional help to get motivated in the gym because she loves exercising and does it for at least 45 minutes every single day.

She told the US December issue of InStyle magazine: ''I don't have a trainer. Crazy, right? But I don't need anyone to motivate me. I love exercise, even things like the elliptical and stretching.

''I'm obsessed with hula-hooping. I do it for 20 minutes a day. I don't use the old-fashioned hollow plastic kind we had when we were kids, but I discovered a new one at Danskin that's smaller and weighted.

''I'm lucky to have a pool at my house in Westchester. I do laps for half hour a day where I can. I either work out in the house or, when I'm at our apartment in Manhattan, at an Equinox. I do at least 45 minutes a day, seven days a week.''

The mother-of-two - who shares daughter Carys, nine, and son Dylan, 12, with her husband Michael Douglas - admitted that she tries to stick to a healthy diet most of the time.

She said: ''I don't deny myself food. I'm no saint. I love butter and cream, but I also eat lots of grains and fruits.''

The Welsh born actress also revealed that she feels her inner strength and confidence makes her feel more glamorous.

She said: ''Being glamorous is about strength and confidence. It's black and white - dramatic. You have to be as strong as a woman.''

However, the actress hasn't always been so low maintenance and previously claimed: ''I came out of the womb wearing make-up.''