Myth or Truth?
You have to focus on specific muscles to tone your core....MYTH. The best way to strengthen your abs and save time doing it, is to do total body, not spot toning, moves. Any posture that requires body awareness and slow movement is more challenging than endless reps on the floor. Standing moves will help you achieve firm flat abs because by requiring you to maintain your balance, they force you to engage all your ab muscles in a way that spot training moves don't.
Weight Watchers Magazine July/August 2011