Day 20: Plank Pose
"Start on your hands and knees, shoulders over wrists and hips over knees. Straighten your legs. Look forward and down, and breathe in and out through your nose, holding 5-10 breaths — or longer if you can," says Lauren Imparato, founder and owner of New York City’s I.AM.YOU. Studio and author of RETOX . "This pose will help tone your arms, back, and abs without building bulk and will keep you focused." To make it more of a challenge, try holding it as you listen to a song you like and see if you can push yourself one verse past when you feel like giving up.