randy does circuit training as well and that is why they have the 2 best gas tanks in the ufc. they aren't concerned with bulking up but with having great endurance.
What does bulking up have to do with anything? Bulking up means eating more calories.
About the OP, I don't think Franklin's workout program is the best, but it works for him, and does a pretty good job at giving him some good muscular endurance. I'd personally go about it a different way, but then again, I'm not as successful as Rich Franklin, so no need to fix what isn't broken.