Pippa Middleton Tackles a Triathlon

Jennifer D'Angelo Friedman, Self.com
Omg Balanced Living

If you've been wondering since the royal wedding how Pippa Middleton scores that round-but-firm booty, you're not alone. In fact, there's an entire Facebook page dedicated to her, um, assets.But this weekend, we learned that Kate Middleton's 27-year-old sister owes her famous rear -- and physique -- to more than just great genes.

On Saturday, she crossed the finish line at the GE Blenheim Triathlon in Woodstock, England. Interested in doing a race yourself? Gain inspiration from four more celebs who have sweated it out in marathons or triathlons. 

Cross-Train with P90X

Jennifer Lopez
J-Lo's toned-yet-lean legs stole the show on "American Idol" this year. And while she gets her gorgeous gam moves from celeb trainer Tracy Anderson, the singer also participated in the Nautica Malibu Triathlon in 2008.

Katie Holmes
Mrs. Tom Cruise successfully completed the 26.2-mile New York City Marathon in 2007. At the time, Cruise told People magazine that he was "very" proud of Holmes, who trained for three months.

Almost-Barefoot Sneakers You'll Love

Reese Witherspoon
We know Reese studied the trapeze for "Water for Elephants," but she also took part in a parent-child triathlon with her daughter Ava last year. The actress reportedly competed in the bicycling portion of the race while Ava swam and did the running.

Cute Biking Essentials For Beginner to Expert Riders

Anna Kournikova
The tennis star participated in the Second Annual Nautica South Beach Triathlon in Miami, Florida, in 2009, which included a half-mile ocean swim, 19 miles of biking, and a four-mile run on the beach.

Feeling motivated? So are we. Have you ever done a marathon or triathlon?

More Celebrity Features on Yahoo!:
Pippa Middleton Completes Blenheim Triathlon
Pippa Middleton: Surprise Star of the Royal Wedding
Was Pippa Middleton's Wedding Look Inspired by Cameron Diaz?

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