Check your grammar now! : intense or paroxysmal excitement; especially : the rapid pleasurable release of neuromuscular tensions at the height of sexual arousal that is usually accompanied by the ejaculation of semen in the male and by vaginal contractions in the female.
So, even though you may have only burned 250 calories during your HIIT workout, the total calories burned after will be far greater. Those calories, plus the 250 burned during the HIIT workout surpasses the 400 burned during the slow, steady-state workout by a LONG, LONG way.
This has recently been disproved, as a new and exciting way to perform cardio has arisen. The best cardio for burning off that stubborn fat will have you in the gym shorter than you'd expect. This cardio is called HIIT-High Intensity Interval Training. The concept is pretty simple. You transition from low-moderate intensity intervals to very high intensity intervals.