The Princess of Wales is never one to shy away from a sporting challenge while out on engagements.
Recently, we've seen her win a gruelling spin race against her husband Prince William, play tennis with Grand Slam champion Emma Raducanu and take on rugby training at Twickenham.
So taking part in the London Marathon seems like it would be a natural fit for the sporty princess.
But as runners pound the streets of the capital today taking part in the 26-mile course, Kate will not be among them.
And it appears she never will be even if she wanted to as one important thing is holding her back.
Journalist Bryony Gordon, who has met Kate and completed the marathon, revealed she asked her if she would consider doing it.
But Bryony told Runner's World: "I can’t remember exactly what happened, but I was like, ‘Are you going to run the marathon?’
"And she was like, ‘Oh I can’t because security is a bit difficult.’ But I was like, ‘Sure, yeah, yeah, good excuse. If I can do it, anyone can.'"
Despite not being able to take part, Kate did attend the 2017 London Marathon when her mental health cause Heads Together was one of the main charities for that year - although she didn't do any running.
However, there is one royal who has completed the famous London challenge - Princess Beatrice, and she even set a record.
In 2010, she ran the race for her mother Sarah Ferguson's charity Children in Crisis and was one of 34 runners who joined together to form a human caterpillar and were tied to each other while running the route.
Among the others taking part were her then-boyfriend Dave Clarke and friends Sam and Holly Branson.
Beatrice donned a fluorescent tutu and sweatbands for the race and was pictured cheering with her medal after crossing the finishing line.
And impressively, the group broke the record for being the most people to finish a marathon while tied together.
Meanwhile, Sophie, the new Duchess of Edinburgh, completed part of the marathon in 2020 when people ran it socially distanced.
She ran 1.5 miles in the pouring rain alongside one of the 45,000 runners taking on the challenge. She joined Tomas, who was running to raise cash for Mencap, which she is patron of.
The charity offers support for carers and families of children with learning disabilities, as well as the children themselves.
