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Pippa pictured after finishing the 'Race Across America' in Annapolis, Maryland on June 20. Source: Getty Images
Pippa pictured after finishing the 'Race Across America' in Annapolis, Maryland on June 20. Source: Getty Images

After completing a gruelling month-long cycling challenge across America in June, Pippa Middleton has now completed her latest challenge - a four mile swim across a tidal shipping strait in Turkey.

The 30-year-old younger sister of the Duchess of Cambridge has shared the secrets of the protein packed diet she underwent in preparation for the Bosphorus Cross Continental Swimming Race, which she completed with her brother, James, 27.

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Pippa explained to Hello! magazine how she prepared for the challenge, admitting she started training back in June.

She said: "Nothing could have prepared me for the experience of the race itself in Istanbul… The swim requires not only speed and athleticism but also the nous to navigate yourself on the right course."

Pippa said "wholesome carbs" were essential for preparing for the race, including lots of protein, brown rice, lentils and quinoa.

She explained: "To maintain energy I try to eat more protein, particularly fish or chicken… a lot of people swear by carb-loading in the run-up to an event but it doesn't really work for me, so I just up my protein intake."

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The socialite claims to have feasted on seafood and a bowl of porridge with honey, banana and nuts in the morning in order to give her body plenty of energy for the grueling swim.

In the end, her hard work and diet paid off, as she completed the race in one hour and five minutes, beating her brother James.

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She joked: "He said if he'd shaved, he would have beaten me. But of course!"

The sporty siblings also teamed up for the 'Race Across America' cycling challenge in June and helped raise more than $36,000 in donations.

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"The challenge of riding across the Rockies, coping with the heat of the Arizona desert and climbing over 170,000 vertical feet in the six days was incredibly tough, but every inch of the 3,000-mile race was worth it to help the BHF fight heart disease," she says.

Pippa, who is a British Heart Foundation ambassador, is also auctioning off her bespoke bicycle to raise more funds.

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