Actually, he didn't mention sets/reps, so it might not be all that much volume. What he did do though, which might not be a real bad idea from a bodybuilding perspective, is to take a major move and follow it up with a couple of others. If I was doing his routine, I would hit the major move for 2-3 work sets, then take the follow ons for 1-2 work sets (not including any necessary warmups), and it's entirely possible he could get through it with major recuperation. I'm not a big fan of going intensly for 5 days straight though, even with a split. Yes, some areas are resting where others are working, but with the exception of the biceps day, the CNS is still getting hammered. Might sound strange coming from me, as I go 3 on 1 off, full body, sometimes mutiple sessions/ day, but the intensities are varied, as is the emphasis on conditioning strength, and volume. But, if you're not having problems with recuperation, why fix what isn't broken?