Cindy Crawford has ditched "tough workouts".

The 54-year-old supermodel has opened up about her journey with exercise and her diet over the years, and admitted she used to get "annoyed" seeing Kate Moss, 47, eating fast food and smoking cigarettes and still staying the same size, because if she overindulged and didn't change her eating habits, she wouldn't fit in the outfits she models.

Cindy told the March issue of Red magazine - of which she is the cover star - that: "I don’t like the word ‘diet’, but I still choose to eat well. I was never one of the people who could eat what I wanted – even I used to get annoyed when Kate Moss would be eating a burger and fries and smoking a cigarette! When I moved to New York, I knew I was going to have to change the way I ate or I wouldn’t be able to get into the clothes – and, by the way, the clothes were much bigger then than the sample sizes now. But the way I’ve exercised has changed."

The 'Fair Game' star - whose children, Presley, 21, and Kaia, 19, whom she has with husband Rande Gerber, followed her into modelling - explained how after she had kids she relied on exercise to "energise” her, and now the “goal" is to not "get hurt" by doing less rigorous routines.

She continued: " In my 20s, I would workout hard and flop down on the couch. Then, I had little kids and realised my workouts couldn’t tire me any more, they actually had to energise me instead. Now my goal is not to get hurt. So, I have added a lot more stretching and Pilates, and I don’t feel as compelled to do those tough workouts any more."

Cindy also opened up about embracing her "insecurities and flaws" as she's gotten older.

She said: "When you’re young, you have the beauty and strength of youth, but you’re really hard on yourself and you haven’t done the work on the inside yet. As you get older, you’ve figured out who you are, but you’re thinking, 'That’s not where it used to be any more!' Maybe that’s the point – having insecurities and flaws is what makes us human."

Read the full interview with Cindy Crawford in the March issue of Red, on sale the 4th of February. It is available in all supermarkets and online at MagsDirect