Hilary & Haylie: Sisters Who Wear Spandex Together, Stay Together

Sisters Hilary and Haylie Duff worked it out Wednesday at a gym in West Hollywood. Even as they left all sweaty, the celebrity siblings still looked glamorous with their over-sized shades and sleek, black workout gear! These sisters can turn sporty spandex into chic attire — well, almost. Regardless of her outfit, Hilary still made time to flash a smile at photogs!

OK! GALLERY: HILARY DUFF DRESSES BOYISHLY BUT RUNS GIRLY ERRANDS

Hillary and Haylie have been spotted working out quite frequently lately.

Could the duo be prepping for Hilary's pending nuptials?

The actress is engaged to hockey star Mike Comrie and wedding bells are definitely in the near future for the couple — who got engaged in earlier this year in Hawaii!