And they're off! Kate, William and Harry race in a 100M relay sprint for Heads Together

Talk about sibling rivalry. They may not be running a marathon any time soon, but they sure can sprint!

The Duke and Duchess of Cambridge and Prince Harry were out in support today for their Heads Together teams for the London Marathon -- and after meeting with and encouraging those running this year, they took off on a little sprint themselves. Taking part in a relay with several other Heads Together team members, the royals threw themselves into the first 100 meter sprint of the relay.

Prince Harry came in first (but, to be fair, he once totally beat Usain Bolt in a race), with William not far behind. Kate definitely held her own -- getting off to a faster start than William, though he wound up taking second place away from her in the end!

Whether or not the royal trio planned on participating in training day, they sure seemed to have fun, to the delight of the day's participants.

Making a point to have a strong Heads Together team at the London Marathon this year further supports William, Kate and Harry's goal to eliminate the stigmas around mental health. Taking over as the 2017 Virgin Money London Marathon Charity of the Year, the organization, and the famous trio behind it, are every day getting closer to that goal.

See more photos from the above day -- including the royal sprint!

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