I read in a nutrion book some time ago and it claimed aerobic activity to be the best for fat loss. According to the book aerobic activity over 20mins is when the body stopped using glucose for energy and epinephrine of some sort another was released to tell the body to start emptying its fat cells. It said that anaerobic activity or HIIT as we call it had little fat burning effect becuase of the demand for energy/oxygen etc on the body was great and so fast that it has no choice but to burn up readily available glucose and create lactic acid in your muscles with results in 'owed' oxygen....
Keep in mind that i buy books at the thrift store so this may have been written awhile ago but it is a nutrition textbook written for what looks to be a college level nutrition class.
But it seems as though according to this book more fat loss could be gained by aerobic activity past 20mins rather than HIIT. In hind-sight, it also said that 124g of protein is the base 148g to be hi....so
The Commander-in-Chief answers him while chasing a fly
Saying, "Death to all those who would whimper and cry"
And dropping a bar bell he points to the sky
Saying, "The sun's not yellow it's chicken."
Throw out the book and forget everything you've read in it.
Big Boss Man, look at this thread and the post (#2) by Anthony. He knows his ish and he breaks this particular issue down.
The only time I see long SS cardio applicable over HIIT is when one is on PSMF or low carb/low cal diets. The energy to do HIIT is not there and may lead to over-depletion of the legs.