You can watch Cereal Killers the movie for free until July 4th at articles.mercola.com/sites/... which is documentary that follows Donal O'Neill as he switches to a Low Carb High Fat diet and High Intensity Interval Training (HIIT).
It's well worth watching if you've got the time, if just to expand your knowledge on the subject if nothing else.
I've personally been doing HIIT based program for the past 3 weeks, switching from my daily slog of around 12km plus an hour of cardio I used to do, and so far I am loving the results!