I just came across this polished-looking piece on Tabata Intervals titled Guerilla Cardio (PDF). The focus is on fat-burning, but also includes references to many of the training benefits of Tabatas. On the fat-burning front, there's this note:
To prevent overtraining, try to incorporate the program on your weight training "off days." For instance, I train with weights on Monday, Wednesday and Friday, and perform my Guerrilla Cardio sessions on Tuesday, Thursday and Saturday mornings, before I eat anything. (Studies show cardiovascular exercise performed first thing in the morning, on an empty stomach, burns up to three times more fat than the same amount of exercise performed later in the afternoon!)
Scientists are divided on this idea. Tom Venuto covers it well. Personally, the idea of tackling something as punishing as Tabata sprints upon waking, on an empty stomach, is unappealing, to say the least.
Speaking of sprints, they are the Tabata exercise of choice as outlined by Guerilla Cardio:
Now, while Guerrilla Cardio can be applied to all sorts of activities—the stationary bike, stairstepper, etc.—I would highly recommend you stick to sprinting for a couple of reasons . . .
First, all else being equal, sprinting elicits a significantly higher peak oxygen consumption (VO2 peak) than do other modes of cardiovascular exercise, according to researchers from the University of Missouri, Columbia, who recently compared treadmill sprinting to high-intensity exercise on a stationary skier, shuffle skier, stairstepper, stationary bike and rower. This is important because this new research shows the closer you come to your VO2 peak while exercising, the more fat you'll burn once that exercise session is over.
Second, sprinting is tough. In fact, it's so tough, many people actually fear doing it, which is exactly why I recommend it. (Remember, if you move away from what you fear, you get weaker. But, when you move toward what you fear, you get stronger!)
Leaving the focus on fat loss aside, and having applied quite a few different exercises to the Tabata protocol, there's no question in my mind that sprinting is the toughest, lung-wise, and by a wide margin, in many cases.
(Burpees are the closest contender, and while I personally feel like they take the title for whole-body muscle fatigue, lactic burn from head-to-toe, etc., I don't think they hit the lungs quite as hard as sprints. But that may be because my burpee technique limits my repetition ceiling, whereas sprints don't have a comparable personal limitation.)
