Ironically enough, the ultimate six pack exercise has almost nothing to do with building up the muscles that create the six pack.
It is designed to reveal the muscles and get that toned, sexy look everyone wants.
What is this mystery style of exercise? In most cases it is known as High Intensity Interval Training (HIIT).
It is more strenuous than steady-state cardio, so it burns more calories both during and after.
It also takes less time to perform, topping off at 20-25 minutes and never needing to lengthen those sessions no matter how long you've been doing them.
It should be done at most every other day to allow your body to repair itself.
It is preformed by doing any activity that gets the heart rate up and turning up the speed to max in quick bursts.
This brings the heart rate towards threshold levels which has a whole host of other benefits.
There are periods of lesser exertion between the bursts in order to catch your breath.
To make it clearer, take sprinting for instance.
If the sprint lasts too long you are pacing yourself and it is no longer a sprint.
The key is in that high level of exertion, so it requires short rest periods between sprints.
Another form of HIIT has been popularized under the name turbulence training.
This is basically fast-paced circuit training.
It usually takes a few exercises back to back to achieve the desired heart rate, but it also has the benefit of helping maintain your muscles while you are losing fat.
HIIT can be very mentally draining to start with.
Something that may help to get you going is starting a sport that involves sprinting in this fashion.
The competition and fun factor helps to ease up on the mental wear.
If you've done the math, this six pack exercise may only take you 60-80 minutes per week.
It may not seem like enough from an outside view.
You've probably tried and failed with many programs that require far more time investment, but keep in mind that quality trumps quantity in this case.
Besides, it will seem like more than enough when you're doing it.