Kate Middleton has always received praise for her stylish and gorgeous appearance. While her taste in fashion is part of the reason why she always looks stunning, her slender and tall physique are another set of factors.

The Duchess of Cambridge has been known to be a lover of sports. Since her university days, reports have revealed that she engaged in a lot of sports and activities.

Some of these activities include tennis and rowing. Running is also another activity that she loves, according to the Daily Express. This is why it is not surprising that she has been able to maintain her figure even after giving birth to three kids.

Sources from the publication said that she always does cardio, as much as possible. It is also said that she regularly runs either with her only daughter, Princess Charlotte or with the family pet, Lupo at her side.

While cardio is, reportedly, one of the things that allow her to maintain her slim physique, this is not entirely the one that keeps her stomach "flat" and toned. As stated, she does another set of physical routine that helps with this.

A source close to the matter, reportedly, shared that Kate Middleton loves doing planks, aside from her running routines. This is the Duchess' "secret," the source told the Daily Mail. As explained, Kate's regular planks are the ones that "tightens her muscles."

The source then said that there are "three elements" to this routine of the Duchess. These are the basic and side planks, and the "prone sky dive."

It is also said that the mother of three can hold each of these variations for "45 seconds or longer." Not to mention, Kate Middleton repeats each of them for "at least ten times," the source added.

Alongside running and planks, the Duchess of Cambridge also, reportedly, continues to keep up with her sports even today. As shared with the publications, Kate and Pippa Middleton always "enjoy" strenuous aqua aerobic sessions, especially when they are not both busy.

In terms of her diet, OK! asserted that Kate Middleton sticks to meal routines that are "packed with vitamins" and antioxidants. For breakfast, the Duchess' go-to meal is a "smoothie."

She will then, reportedly, enjoy salads for her lunch. As for her snacks, she, reportedly, enjoys "skin-boosting" goji berries. At times when her "sweet cravings" emerge, sources said that she loves to indulge in berries with almond milk.