That’s right! I come back to the high-intensity “honest workout” more often than any other for maximizing muscle-fibre growth in the quickest possible time for the advanced bodybuilder.
Working within the 8×8 guidelines is not sufficient to guarantee gains. You must exhaust each muscle with the right tempo and weight resistance. I recommend that you reduce the rest time between sets to 15-20 seconds, ultimately not even letting go of the bar between sets. But be careful not to overpump or overtrain. The secret is to train hard for no more than 45 minutes.
I would far rather train an advanced bodybuilder two or even three times a day, allowing a 72-hour rest period for the muscles afterwards, than to train only once a day with insufficient recuperation time.
The 8×8 workout can be extremely tough, not only on the muscles but also on the cardiovascular system, especially when minimum rest is taken between sets. The secret of short-term recuperation is oxygen loading. Try breathing twice per repetition. This will force oxygen into the bloodstream, and certainly help the pump. After a set, concentrate on hyperventilating (5-10 slow breaths through pursed lips) to pay back the oxygen debt you will incur from the intense sets of 8 reps.