I had been doing sprintervals as my exercise in 09 back before discovering GM. I agree its a great workout! Whenever I JUST run I am exhausted and yet don't lose anything, for whatever reason sprintervals is a great workout for me (which I often forget about doing :/ )
I haven't been really keeping up with GM, other than occasionally listening to the mp3 (maybe 2 nights a week if i'm lucky) and still eating chia seeds every day. I REALLY need to sit down and re-read the book and be reminded about all the extra credit visualizations and tricks.
We've had a TERRIBLE winter here and when its been even remotely warm enough to manage going outside, there is still too much ice and snow everywhere for me to do much in the way of exercise. Its an excuse, but at the same time I can't afford a gym membership and I don't enjoy doing workout tapes, and I've been lazy thanks to the winter and personal issues.
However, I'm dying to get out there again, so once this horrifying winter is finally over, I'll be right back to my sprintervals!!!