As you already know, I’m all about saving time. So I say, “work shorter, but harder.” When you don’t have much time, do this little ab routine to flatten your tummy quickly.
Here I am using the TRX Suspension Trainer, but you can use a big exercise ball or paper plates. Just place the front tops of your feet on the ball, or your toes onto paper plates and voila! Do two to three sets, exhale just before you start the movement, then draw the belly button towards your spine as you bring your knees in.