Many classic abs exercises are done on the floor, from planks to crunches and sit-ups. There are a lot of core exercises that you can perform standing up to really engage your midsection. Standing core exercises offer unique benefits you can't find on a mat. They are a great addition to any workout. Evan Williams, CSCS CPT, certified strength coach, and founder of E2G Performance tells SELF that core strength is important because "the center of the human body" is the core. Williams explains that when you perform functional movements,...