SARAH WASSNER FLYNN is a longtime writer for National Geographic Kids. She loves writing, running, and triathlons. When she's not writing about races, she's usually training or competing in one. She also writes nonfiction books and articles for kids and teens, like The National Geographic Kids National Park Guide U.S.A., This Book Stinks, Weird But True! Know-It-All Greek Mythology, and The Girl's Life Guide to the Most Amazing You.