Sorry about the title but apt :)
I'd read this blog entry on TGU ages and ages ago, and largely due to fogetting and, if I'm honest, skepticism. Still though, one hour today on the Curragh plains with the podcast having me running sprints (intervals, which I've used for climbing to great affect).
Having not being running for a few weeks due to a problematic foot injury, I suffered. A lot. It's not as if someone (i.e. Lance Armstrong) is screaming in your ear, but it definitely makes a change to just running with some music in the background.
To be fair, even if I had been running regularly recently, I still would be suffering now - it's set up for all abilities. If you're looking for some motivation, give the podcasts a try.
Image: Now I feel like he looks in that image ;)