I got a question from a reader regarding what I thought about HIIT (high intensity interval training) and the Tabata protocol in particular. I won't post the entire question, as it was a bit lengthy and contained other questions on different subjects as well, but I will provide my thoughts on HIIT and Tabata style interval workouts. I should also note much of what you'll find below over laps with three posts (which you can find HERE, HERE, & HERE) I made in the last two weeks, so, if you are a regular reader, some of this is redundant. That being said, the other posts from past weeks compliment this one pretty well, so, if you feel so inclined-and are a new visitor to the blog-you might want to check those out as well.
A couple of things before I get into my thoughts. HIIT, in my opinion, is very brief, very hard, very uncomfortable interval training. Typically, HIIT workouts (at least how I define and use them) should not exceed 10:00. They generally consist of 10-30 second near maximal work periods with an incomplete recovery. When I say "incomplete recovery" I'm talking about a work to rest ratio of 1:1 OR LESS. This is why true HIIT, in my opinion, literally cannot exceed 10:00...it's just too fricking hard.
HIIT is NOT to be confused with traditional interval training. I would define traditional interval training as workouts consisting of longer work periods (30-90 seconds) with work to rest ratios closer to 1:2 or 1:3. Also, traditional interval training workouts are longer (again, my interpretation and application): 20-30 minutes.
I'm not implying that traditional interval work is not hard-it certainly is. But from a relative standpoint, traditional interval workouts are a helluva lot less demanding than HIIT style interval workouts...and Tabata style workouts certainly fall within the realm of HIIT.
Before I proceed with my opinion on HIIT and Tabata style workouts, for those of you not familiar with the Tabata protocol, just GO HERE and read the brief "Tabata Method" section. This will give you a primer.
Ok, now that we've got all that out of the way, here are my thoughts. Most people use HIIT and/or Tabata style workouts for fat loss. There is a deeply ingrained belief out there that this style of training is superior for fat loss. The belief is that this style of training elevates metabolic rate for hours upon hours after a workout is over (I've even seen some people claim it elevates metabolism for days), and that it turns your body into a "fat burning machine" or a "human inferno". Furthermore, many believe 2 or 3 of these brief-yet very demanding-workouts per week can produce this effect.
Without going into detail, let me just say that those who buy into the above are misguided. If you really look into the research on post workout calorie expenditure and metabolic rate elevation, I think you'll find it's not all that significant (Lyle McDonald does a great job discussing this topic at length in THIS SERIES of posts). Now, I'm not saying HIIT or Tabata style workouts cannot-or should not-be used when focusing on fat loss. They certainly are tools in the toolbox, but I think they should be used prudently and intelligently in conjunction with other types of training (namely traditional strength training and steady state lower intensity cardio workouts and/or traditional interval training) and certainly in conjunction with a calorie controlled diet.
To me, and for me (and my clients), the real beauty and value of HIIT and Tabata style workouts comes in the way of CONDITIONING benefits...NOT fat loss. These workouts provide very efficient conditioning solutions. If you have no contraindications, have a base level of conditioning, and are willing to work, you can increase or maintain your conditioning and work capacity in 10:00 a couple of times per week. Despite some peoples misguided beliefs, they certainly are not going to result in a huge net calorie expenditure (although the rate of of calorie expenditure during the work periods is through the roof), but if it's time efficient conditioning you are after, these types of workouts give you a great bang for your buck. I think they are ideal to tack on to the end of your strength training workouts, especially if you are someone focusing on strength or mass gains, but who also wants to stay in condition without interfering with recovery between weight training workouts.
So, it should be clear I don't think HIIT or Tabata style workouts are the panacea for rapid fat loss, but I DO think they are worth their weight in gold from a conditioning perspective. However, due to the intense nature of these workouts, I don't think you can do a lot of this stuff. They are as much psychologically demanding as they are physically demanding. 2 or 3 of these per week is plenty, and, again, I think they should be combined with other forms of training if fat loss is what you are after. Trying to do 4-5 HIIT workouts, and trying to do them for 20-30 minutes is a bad idea.
A good approach (for a stand alone conditioning and calorie burning workout), is to open up the workout with a 10:00 HIIT style protocol, and then either go out for a 30 minute walk or do 20-30 minutes of steady state cardio after the HIIT (this could also be done later in the day). If you did this 3 days/week, and strength trained 3 other days/week, you'd have a nice overall program. Alternatively, as I discussed above, you could just tack the HIIT on to the end of your strength workouts and then do longer duration cardio of a more moderate intensity on the days you don't strength train.
Before I conclude, allow me to rant a bit. A lot of people out there claiming to be doing Tabata workouts are either lying or don't understand the original Tabata protocol as it was prescribed in the original research study. If you do a true Tabata protocol (4:00 in duration), that will be all you do in the way of training for the day. You will lie on the floor and will be about as uncomfortable as you ever have been in your life. If you do 8 20 sec. sprints on a Schwynn Airdyne bike, alternated with 10 sec. rest periods, and you hit 800 watts on the sprints, you'll understand what I'm talking about.
When I see fitness enthusiasts on the internet (you know, because everybody is world class and hardcore on the net) claiming to have done 4 sets of "Tabatas", I burst out laughing, because I've done the real Tabata protocol, and I know how grueling it is. Also, doing Kettlebell Tabata workouts, body weight Tabata workouts, etc., while no doubt "hard", is not the real thing. You can, in fact, do multiple rounds of :20/:10 Kettlebell swings and not want to shoot yourself afterward. I can't say the same thing for performing one Tabata protocol, properly, on an Airdyne bike.