Pippa Middleton participated in the Highland Cross challenge in Scotland today. The event goes from the West to the East Coast and includes a 20-mile run and 30-mile bike ride. Pippa and her friends had to be invited to the race, which they arrived at by helicopter. The sister of the Duchess of Cambridge also finished a triathlon in England earlier this month, though recently she's been trading her running shoes for heels to attend events. She and Kate went to a pal's wedding last weekend and Pippa joined her family for a party at the Goring Hotel. Pippa was also spotted on a casual date with her ex George Percy following the news that she had split with longtime boyfriend Alex Loudon.