And never underestimate the value of doing squats the whole time you're brushing your teeth," she tells Women's Health. You'll feel them in your glutes (buttocks), core muscles, and back. You'll feel them in your glutes (buttocks), core muscles, and back. If you're looking to get back into regular exercise like Hannah did, combining something you're already doing with a new practice is worth trying. doing squats (new) while brushing your teeth (old).