The literature shows that HIIT is more efficient at burning fat and retaining muscle...at least, in a certain bf range.
We can also look at the popularity and success of LISS at getting people super ripped for competition.
Given the caloric needs and hormonal response to HIIT, I feel its best suited for the first 6-8 weeks of pre-contest, or at least to drop someone down to the 4-7% range. Beyond that range, you might expect a great loss in muscle with the demands of HIIT combined with a decreasing caloric intake needed to get into contest shape...which is why I suggested LISS for the final weeks, or to drop from <7 to 3-4%
Br