It's no surprise that the Prince and Princess of Wales enjoy being competitive and enjoying sports - both separately and together.
Princess Kate and Prince William enjoy going on bike rides together and trying to out-do one another in competitive sports such as tennis. However, there is one sport the mum-of-three enjoys that her husband just can't get behind.
Taking to The Good, The Bad and The Rugby podcast, Kate explained: "Personally, I love swimming. Cold swimming, the colder the better. I absolutely love it. It's slightly to the point where William is like, 'you're crazy'."
The sporty royal continued: "It's dark and it's raining and I seek out the cold water. I love it, but I wouldn't want to be put through my paces in a freezing sub-zero ice bath." Mike, who shares a very special bond with William and Kate, added: "We all get together, I know she'll make me do something."
Previously, the Princess shared that she even has a special robe she uses after swims. She made the comment after seeing someone wearing a robe to keep them warm in the rain, when she was due to meet the Central Beacons Mountain Rescue Team in Wales.
Cold water swimming reportedly has strong mental health benefits while also being a good physical exercise for the body. That being said, it's not without its risks.
According to the Outdoor Swimming Society, some of the biggest risk factors for the extreme hobby are cold shock, cold incapacitation, which is where your swimming becomes slower and more ragged, cramp, hypothermia and cold water urticaria, which are hives induced by the cold.
Kate and Mike spoke further about the royal's competitive personality. He said: "I'm not going to say you're uber competitive," pausing to give a nod, before Kate claimed: "I'm not competitive at all." Mike replied: "I've seen her play beer pong!".
The Prince of Wales also has a hobby that Kate is scared of. During a visit to the Scottish city of Dundee back in 2015, Kate was asked during a royal engagement whether William would still ride a motorbike from time to time. She said: "He's still riding it. It always fills me with horror when he goes out on it. I'm terrified. Hopefully, I'm going to keep George off it."
However, during a trip to Isle of Man TT motorcycle races, William explained that he wasn't riding anymore, saying: "I'm a dad of three. I have to tone it down. I miss the big trips, for me biking was always about being with everybody else."