I commented on this over at the Body By Science site
Just watched the BBC Horizon programme and the key bit was about what they called HIT but was really HIIT - interval training on an exercise bike. This benefitted the subject who improved his insulin sensitivity but - due they said to his genetics - did not improve his VO2 Max. They explained how this intense exercise had an impact on his glucose metabolism, emptying his muscles of glycogen so that they were able to absorb more glucose form the blood.
This was good in that we are inching along towards an understanding of the benefits of intense exercise, but disappointing in that we never seem to go the whole way from interval training to intense resistance training. If you really want to empty your glycogen stores and have some intense exercise, then go for BBS style HIT!
The other thing was that I found it disconcerting that the scientist who was extolling HIIT was not lean but on the way to obesity…..
I go over all of this science in by book Hillfit by the way.
Martin Gibala has been researching this too for a while and at least he looks lean