Listing tennis, hockey and running among just a handful of her favourite pastimes, we’ve often wondered why we’ve never seen Kate Middleton taking part in a marathon.
After all, she’s regularly seen donning her trainers during public appearances to promote fitness, attending the London Marathon last year when her mental health charity Heads Together was the event's chosen partner of that year.
However, there’s one very understandable reason why we’ll never see the mother-of-three on the starting line of a marathon.
Earlier this week, journalist and friend Bryony Gordon discussed her close relationship to the royals and the first time she met the Duchess of Cambridge during an appearance on ITV's Loose Women.
After being introduced to the royal to discuss Heads Together at the sporting event, Gordon says she asked Kate if she’d be running the marathon.
‘Oh no, security and all that,’ Kate replied, according to Gordon.
In response, the author of Eat, Drink, Run said: ‘If I can do the marathon, you can.’
Despite being unable to run the 26.2mile course, Kate did take part in a 100-metre sprint with Prince William and Prince Harry during a training day for runners taking part in the marathon, and cheered on the runners on the sporting day itself.
Meanwhile, Kate’s younger sister Pippa - who is pregnant with her first child - completed her first marathon in Kenya in 2015.
Opening up about her decision to take part in the gruelling run, the 34-year-old told HELLO!:"I decided that a marathon was a “life box” that needed ticking and this year was my time – despite it being one of the toughest in the world, with temperatures rising to more than 30ºC, at an altitude of 5,550ft and with the possibility of bumping into lions or rhinos."
Pippa also completed the 2016 Great Wall Marathon in China, finishing with a time of 4:54:51 and a position as the 13th fastest female.
A version of this article originally appeared on Elle.com