Most of the science you need to reach the same conclusions as Kurtz79 is high school biology and some basic physics and thermodynamics. Calories are a measure

Most of the science you need to reach the same conclusions as Kurtz79 is high school biology and some basic physics and thermodynamics. Calories are a measure of work (Force x mass). To burn Calories your body has to be doing work of some sort. To burn the same number of Calories in 7 minutes as 45 requires doing an equivalent amount of work. In my case, 45 minutes running is 800 calories. 800 calories in 7 minutes is like 114 Calories/minute. I don't think even maximum anaerobic sprinting comes close to 114 kcal/min, and even if it does I certainly can't maintain that intensity for more than 15-20 seconds. For a comparison, my 2800 lb Honda Civic burns probably 400 kcal/minute in gasoline during city driving at an average speed of 20mph. The article is very vague about how reasonable this 7-minute set of exercises actually is. From the article: Interval training, though, requires intervals; the extremely intense activity must be intermingled with brief periods of recovery. How intense? It doesn't say. This should be possible to measure. To explain more though I will have to read the original paper to see exactly what sort of "benefits" they were talking about and how intense this exercise has to be.