Here is a link to an AMA he did in 2012:
http://www.reddit.com/r/weightroom/c...his_is_my_ama/.
Kind of interesting but he seems to be a big believer in doing lots of DL reps at a lighter weight. And he has a whole (hard to read, lol) paragraph just about how CORE is the most important thing in lifting. Getting it tight, keeping it tight, and controlling it during the lift. So it sounds that even if he's doing high rep DL stuff at submaximal weight, he's able to keep really, really good form and that is his focus. Seems tough "cardio"-wise, though.