How does Kate Middleton stay in shape? This is the secret behind her slim figure

Kate Middleton always looks flawless whenever we see her, but how does she stay in shape all the time?

While she also has an immaculate sense of style, Kate's ability to look fantastic in any dress, skirt or pair of trousers is inevitably a result of her super toned physique.

Of course, Kate’s naturally slim figure is also down to genetics, but it’s no secret the royal mum-of-three is known to enjoy all things sporty and is said to love a tough workout.

How does Kate Middleton stay in shape?

According to a royal insider, there’s one key workout move Kate always relies on to stay slim and toned – and that’s the plank. Kate is reportedly a pro at the core targeting exercise and combines “the basic plank, the side plank and the prone sky dive” for 45 seconds before repeating at least ten times.

Kate also enjoys getting out for a run and is partial to a game of tennis at the courts at the Cambridge’s Norfolk home, Amner Hall.

"It has been the scene of many hard-fought matches, singles and doubles," the source told the Daily Mail.

READ MORE: How Prince George, Princess Charlotte and Prince Louis spend their dinner times

What does Kate eat to stay in shape?

As well as plenty of exercise, Kate also enjoys a balanced, nutritious diet to maintain her slim figure too.

She’s said to have a vitamin packed smoothie for breakfast followed by a salad for lunch and lean meat and veggies for dinner, while snacking on superfood goji berries through the day.

On nights where a takeaway is on the cards, Kate says she treats herself to some spicy Indian food.

The Duchess doesn't rely on a personal chef to feed her kids either. She has revealed she loves to cook and bake with her brood, Prince George, Princess Charlotte and Prince Louis, and recently enjoyed homemade pizza with the children.