How did she do it? Earlier this month, Kate Middleton went back to work and made a handful of royal appearances, and royal fans could not believe how amazing Kate looked just six months after giving birth to her third child. Now, insiders revealed all of the diet tips and exercise tricks that Kate used to help her slim down to her incredible post-baby figure.

Firstly, insiders told the Daily Mail that exercise has always been a “non-negotiable” part of Kate’s daily routine and even more so after she gave birth to Prince Louis. “Kate was very concerned about the effects on her figure of a third child, particularly as she is moving towards her late 30s. So she has made an extra effort in toning up,” an insider said.

kate middleton post baby body
Britain’s Catherine, Duchess of Cambridge, plays tennis as she joins a session with a group during a visit the Coach Core Essex apprenticeship scheme at Basildon Sporting Village in Basildon, southeast England, on October 30, 2018. – The Duke and Duchess of Cambridge visited Coach Core Essex to meet new apprentices, hear from graduates, and learn how the scheme in Essex is engaging a diverse local community with sport. The Duke and Duchess met with new Coach Core apprentices and joined in with their coaching sessions, including tennis and indoor athletics. (Photo by Adrian DENNIS / various sources / AFP) (Photo credit should read ADRIAN DENNIS/AFP/Getty Images) Getty Images

To tone up her abs, Kate performs multiple sets of leg raises while laying on a mat and resting her head on a feather pillow, according to the source. The exercise helps to tighten the ab muscles that separate during pregnancy. On top of the leg raises, Kate also followed the 12-week Mutu System, which is a workout program specifically designed for post-natal women and is intended to tighten the ab muscles and strengthen the pelvic floor.

It also helps that Kate has a workout partner in her sister Pippa, and they both workout together at their private gyms. Other exercises that Kate enjoys to do are spinning on an exercise bike, cycling outdoors, swimming, running, body weight training, yoga, and tennis.

kate middleton post baby figure
LONDON, UNITED KINGDOM – OCTOBER 30: (EMBARGOED FOR PUBLICATION IN UK NEWSPAPERS UNTIL 24 HOURS AFTER CREATE DATE AND TIME) Catherine, Duchess of Cambridge visits Coach Core Essex at Basildon Sporting Village on October 30, 2018 in London, England. (Photo by Max Mumby/Indigo/Getty Images) Getty Images

Kate also pairs healthy eating with her exercise routine, and the combination of a good diet and regular exercise is what helped her trim her waist. She really favors smoothies, and she also drinks a green juice every day — made with spirulina, kale, or spinach.

After the birth of her first child, Prince George, in 2013, Kate was coached by lifestyle guru Louise Parker, who is also the author of Lean for Life: The Cookbook. Louise advises clients not to eat white carbs while working towards their goals. A sample day of Louise’s meal plan includes bircher muesli with oat bran and blueberries for breakfast, oat cakes with peanut butter or hummus for a snack, and a lean protein with salads flavored with ginger, herbs, or lemon for lunch.