Julianne Hough has a rock-hard bikini body. Hough, 37, showed off her abs in a sizzling hot bikini selfie via Instagram on Tuesday, December 9. She rocked a yellow set featuring a triangle top with delicate straps. The Dancing With the Stars cohost teamed her look with low-waisted bottoms complete with barely-there straps. Hough went makeup-free in her selfie while relaxing in a sauna. She gave the camera a pout while wearing her platinum blonde hair down. "💛," she captioned the post.