Gabrielle Union: I Love Jessica Biel's Butt!

Gabrielle Union tells Us Weekly she loves Jessica Biel's butt and stays in shape thanks to a trainer on each coast. Credit: Roger Kisby/Getty; JB Lacroix/WireImage.com

The grass is always greener! Gabrielle Union is one of those seemingly ageless celebs who looks as gorgeous and fit now at 40 as she looked at 27, when she got her big break in the cheerleading movie Bring It On, opposite Kirsten Dunst. But that doesn't mean she's immune to a little body envy every now and then.

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Us Weekly caught up with the Think Like a Man actress on Tuesday, April 16, at the BET Upfronts in New York City, where she admitted to having a little beauty crush on Jessica Biel. Asked what it is she loves most about Justin Timberlake's wife, the star exclaimed, "Her ass!"

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Union herself has a pretty enviable physique, thanks to good genes and "a combination of a lot of cardio, yoga, and pilates." She also has two trainers -- one in Miami, Amad, and one in L.A., A.J. Johnson.

"I do something every day," the longtime girlfriend to NBA star Dwyane Wade told Us. "Rarely do I do it all."

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She's game to at least try it all, though. Last year, she opened up to Us about giving boxing a go -- with less than stellar results. "It sucked, to sum it up," she joked. "It's incredibly hard, and every inch of my body was in pain. And they can hit you back! I didn't get that memo...Getting walloped in the face is never a good thing."