Kim Kardashian in the Dominican Republic on March 30, 2012 and Miley Cyrus in Hawaii on December 29, 2011. Credit: Splash News;

It takes a lot of work to look this good!

Just ask Kim Kardashian, who lost ten pounds in ten days prior to heading to the Dominican Republic with her family in March. In addition to intense daily sweat sessions, "I went gluten-, dairy-, and sugar-free," Kardashian, 31, told Us Weekly of her slimdown plan.

Barbados native Rihanna takes to the water when she wants a workout.

"I love swimming [and doing] anything in the ocean," the "We Found Love" singer, 24, told Us about her approach to staying in shape. "That's very, very good for your body."

Kate Middleton's scene-stealing little sister Pippa Middleton opened up after the Royal Wedding in May 2011 about her secret to getting toned before her sister's nuptials: pilates.

"I have noticed a huge difference in my core strength and posture," Middleton wrote of her experience with the workout.

Tell Us: Whose major bikini moment is your favorite?