Kate Middleton has revealed an unexpected hobby that has left her husband Prince William calling her "crazy."

In a 2023 interview on Mike Tindall's podcast, The Good, The Bad, and The Rugby, the Princess of Wales revealed her unusual hobby of cold water swimming.

"I really, genuinely, love all sports. I can always remember being physical, using our bodies, whether it's walking, climbing the Lake District, in Scotland [or] swimming from a young age," she said.

Kate added, "[My parents] always encouraged us to be physically active and sporty and they always encouraged us into doing team sports and trying things."

Her fondness for cold water swimming, however, stands out, as she explained, "Cold swimming the colder, the better. I absolutely love it. Slightly to the point where William's [saying] 'You're crazy' and it's dark and it's raining. I will go and seek out cold water. I love it."

This hobby has caught attention of many, especially as the future queen, 42, is recovering from her cancer.

Typically, cancer patients are advised to avoid extreme activities, but Princess Kate has remained active, including attending events like Wimbledon with her daughter, Charlotte, and her sister, Pippa Middleton.