Did it for awhile. Yates style. It was ok. Didn't get any super gains from it.
Poliquin wrote a fairly good article and had a suggestion for those wanting to do HIT.
You can google Poliquin and HIT, probably will find it that way.
But it was basically a setup where you would first do around 6 weeks of high volume bodybuilding training, old school. Followed by 6 weeks of HIT. Followed by 6 weeks of German Volume Training. And followed by Max-OT or similar.
Basically, the point Poliquin was trying to get across I guess, is that HIT works very well if you switch to it from a higher volume protocol.
The gains you get is not from previously being "overtrained". But rather from the de-loading, tapering.
But you still need to put in volume training to get results.