Kiefer recommends HIIT to get rid of glycogen, not burn body fat.
Fair point, that's no doubt why he makes such specific recommendations. Still, if there's a routine that flushes the same amount of glycogen while burning more fat I'd certainly be interested to know.
i remember reading something about HIT increases beta-oxidation and fat metabolism and it basically has an overall affect on making your body more thermogenic as a whole… trying to recall where it was from so i can link.