Odd timing. I actually just saw this episode this afternoon with some friends.
For what it's worth, they were doing 20 second sprints. And it seemed like only a couple of them were doing it at a "12", a couple of people were standing still on the treadmill, and more than one ended up grabbing the handrails and windmilling their legs for a few strides. Given all of that, I don't find it impossible to believe.
I do think that the show's producers apply of a lot of creative editing to get the storylines and "drama" that they want, but that's true of all reality television. *shrug* Just my two cents.
2009 BMC Road Racer SL 01 / Specialized Ruby 155
2007 LeMond Reno / Luna Chix Team Saddle
1980-something Lotus Odyssey / Brooks Finesse
1992 Bridgestone RB-2 / Brooks B-17 Imperial
Nada Bike singlespeed / Brooks Team Pro in white