The intense benefits of HIIT (High Intensity Interval Training) cardio workouts have become widely known in the fitness industry in recent years. However, as great as HIIT is, unless you keep your intensity super-high, you're not only going to get sub-optimum results, you'll get poor results. And if you're going to get poor HIIT results, you might as well be doing LSD (Long Slow Distance) training.
So, how do you make sure you get optimum results from your HIIT cardio workouts?
Personally, I think that HIIT is best suited for only a few types of activities. The best is simply running – on the track, in a park, up hills or stairs, etc. Go out and move your tail as fast as you friggin 'can. Behind that, I would say rowing or running on a treadmill. Next might be an elliptical machine, but from there, you're going downhill in the intensity meter. (I hear the versaclimber would be high on that list, but since I've no direct experience on one, I can not comment.)
When using cardio machines, you basically have to look at it this way – which one gets you breathing the hardest? For example, I've done a lot on stationary bikes, and they can be great workouts, but I'm not a big fan when it comes to HIIT. The same goes for stair-stepping machines. There is too much waiting on the machine.
Now, I'm not saying you can not get breathing hard on many of these machines, because you can. But HIIT is not about just breathing hard – it's about breathing as hard as possible. And many machines just do not do it.
One main drawback to doing HIIT cardio workotus is that when they're done correctly, they're really tough on the nervous system. Like very intense strength training, the nervous system is worn down by all the very hard work it has to force the body to produce. This can have negative results on all other facets of your training, and even though your muscular system might not need it, force you to take extra recovery time to keep from being overtrained.
Let's take a look at LSD for a minute. There is not really anyway to short change it, as long as you keep a decent pace and go the distance. And it's going to take a certain amount of cardiovascular condition to get that done.
There is not anything WRONG with LSD. Countless boxers used it for years (Rocky Marciano was known to even do roadwork on the day of his fights – and he was always in great shape), as have many MMAists. Guys like Tito Ortiz, Frank Shamrock, Sean Sherk, and Matt Hughes have all stated that some form of LSD makes up the majority of their conditioning work (outside of fight training).
That said, HIIT can still be more productive. But it has to be done right, or you're doing something that could easily be surpassed by somebody doing LSD.
Train Hard, Rest Hard, Play Hard.