Princess Kate's intriguing hobby is so daring even has told her: "You're crazy."

During an appearance on podcast, revealed she seeks out the most freezing water possible in plumetting temperatures to satisfy her craving for cold water swimming.

Speaking on The Good, The Bad and The Rugby, she said: "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.

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

"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."

As patrons of the WRU, RFU and SRU, Prince William and Princess Kate alongside Princess Anne, Mike's mother-in-law.

Prince William stressed how important sports are for children, especially when it comes to learning about winning and losing, before Kate joked about friendly competition within the family.

The Prince of Wales said: "I think it's really important from a young age to understand how to lose, and why we lose, and to grow from it and what you learn from that process.

"But also to win well, and not boast. There's so many life lessons that help us all through life, in friendship building, in relationship building, workplace, that you gain from those early years of playing team sport."

Princess Kate joked: "I'm really not that competitive, I don't know where this has come from," before admitting she and William have never managed to finish a game of tennis, as "it becomes a mental challenge between the two of us".

When asked about their three children, the Princess of Wales revealed: "As they're growing and trying out different sports - they're obviously still really young - it's going be interesting to see how that grows and develops."