That article made intuitive sense to me (I ignored all the science
) because I used to do intervals back when I was running five days a week (before Crossfit). I'd either do short sprints and jog back or I'd do 15 seconds of full power holding onto the handlebar "running" followed by slow-motion "walking" on the elliptical. Which incidentally got me just as many strange looks as CF does. Anyways, doing this for twenty minutes definitely sucked more than my short sprint or slow long distance days, even though I was only full-out running for 5 minutes. I took my brother to the gym when he was visiting me last winter, and he said it sucked more than anything, which surprised him as he'd just finished running a half marathon. And we were on the wimpy little elliptical! (I'm far too uncoordinated to put my feet on the sides of the treadmill without falling over and didn't want to keep fumbling with the settings, hence the elliptical.) So it had to be the intervals.
I always wondered why the CF intervals didn't suck as bad, but I thought it was because there were other exercises interspersed which used other muscles (etc.) and never considered the rest factor.
So if one wanted to do today's WOD with that stellar research in mind, would you just do 21 deadlifts, take a 2 minute break, and then do the HSPU's and take another 2 minute break?