Jennifer Lopez Rocks Sweats On The Set Of American Idol

Jennifer Lopez was snapped on the American Idol set in Los Angeles yesterday, and even though her face was all glammed up, she arrived in sweats with a bag of potato chips in her hand. See, she's still Jenny from the block!

After a brief stop by wardrobe, J. Lo emerged wearing a sexy black dress and a pair of sky high Christian Louboutin heels, and we have to say, the 42-year-old singer/actress looks better than most starlets in their twenties. Take that, Marc Anthony!