If you own a BOSU you probably use it flat side down. Here is way to shake up your core/ab workout. This move strengthens your entire core, as well challenging those arm muscles.
Place your hands on the outside pointed edges, BOSU flat side up. Keep your body tight and straight, in a plank – arms long and flexed. Slowly lean right keeping plank tight (it’s tempting to raise your backside). Return to middle and rotate left. Repeat several times.