"The Stealth Core Trainer is a board that makes planks fun! There's an app that allows you to play games while holding a plank, and your body is the controller. (Read my full review here.) You can buy the Stealth Core Trainer ($139) on Amazon, and you can also get the Stealth Core Trainer ($99, originally $149) on the official Stealth website." — SB
Image Source: POPSUGAR Photography / Sam Brodsky