I am quite vocal about my feelings about applying the labels of “HIIT” or “Tabata” to what we exercise professionals used to call “Circuit Training”. HIIT- and Tabata-style training can have beneficial cardiorespiratory effects, but it must be clear how these are defined.
The research by Dr. Izumi Tabata and colleagues, published in 1996*, employed an extremely strenuous protocol (IE1 protocol) that included 8 rounds of 20 seconds of very high intensity cycling (170% of VO2max) followed by 10 seconds of recovery four times a week, with an additional steady-state workout on day a week, for six weeks. For most, this intensity is nearly impossible. Moreover, it is absolutely impossible when performing the weight-bearing type exercises that many exercise leaders incorporate in what they call “Tabata”.
HIIT can include an extensive variety of intensity:recovery combinations. These intensities must be high, or we would have to refer to it as moderate-intensity interval training (MIIT)—which can be beneficial, too. In general, the high-intensity intervals need to exceed 80-85% of maximum. The lower the intensity, the longer these sessions need to be to produce significant cardiorespiratory improvement.
There are several issues with performing cycles of weight-bearing resistance exercise for cardiorespiratory benefit. First, there is a high risk of injury. As one fatigues, one’s movement mechanics will break down. The only way to continue is to slow the movement or allow for poor form/technique. The former reduces the stimulus for adaptation; the latter leads to injury. Second, the intensities of these movements are simply not great enough or for a long enough duration to promote substantial improvement.
Are these so-called “HIIT” workouts useless, then? Absolutely not! For one thing, not everyone is looking to substantially improve VO2max. In addition, these are possibly more effective for burning fat than traditional aerobic exercise. There is reasonable evidence that these workouts promote a longer post-exercise energy expenditure that traditional aerobic exercise. That is, they can turn up the metabolic furnace for several hours allowing the exerciser to keep burning calories (perhaps for as much as a day or longer). They also improve muscle endurance. They won’t, however, substantially improve cardiorespiratory endurance or muscle strength. So, specificity applies—you will want to incorporate other forms of exercise to get gains in these areas.
For clarity sake, I propose adopting a new label for these body-weight circuits (for the record, I am not the first to coin this label—bummer). I would prefer to call this “high-intensity interval resistance training” or “HIIRT”. The name might just be catchy enough to be trendy, and it better captures the nature of the exercise. I still use quotation marks around “Tabata” when referring to short duration, ultra-high-intensity interval training on stationary cycles, rowing machines, etc. (though “burst training” is still a better label) to differentiate the training from longer HIIT programs for cardiorespiratory endurance and to demonstrate understanding that we are probably not coming close to the prescribed 170% VO2max.
HIIRT would be reserved for high-intensity body-weight (or otherwise resisted) intervals—what we are seeing as a trend in many fitness centers. These should be directed at muscle endurance and body composition (not considered “cardio”) and can be performed several times a week in conjunction with a strength and/or cardiorespiratory training program.
Typical HIIRT programs include circuits of several exercises (e.g., 5) performed for a specified duration (e.g., 20-30 seconds) or repetitions (e.g., 10-20 reps) repeat for a specified number of sets (e.g., 5) with a period of rest (e.g., 30-60 seconds) in between. There is a tremendous opportunity for variation. Another way I like to do HIIRT is with a partner—alternating sets until the circuit is finished. My favorite Bulgarian bag HIIRT workout is my “Core 550” workout. The Core 550 takes less than 10 minutes and includes 10 sets of 10 repetitions each of:
Hip thrusts (think kettlebell swing).
Side toss, right.
Side toss, left.
Spin, right.
Spin, left.
The rest between sets (not exercises) is usually 30-60 seconds.
This is great for burning some calories. I estimate 150 kcal for the session with a 17-kg bag, not counting the elevated post-exercise energy expenditure. It is also great for an athletic core (because of the extensive rotational acceleration and deceleration).
Be creative. Most of all, spread the word. Let’s make “HIIRT” the standard label!
Be your best today; be better tomorrow!
Carpe momento!
* Tabata, Izumi; Nishimura, Kouji; Kouzaki, Motoki; Hirai, Yuusuke; Ogita, Futoshi; Miyachi, Motohiko; Yamamoto, Kaoru (1996). Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Medicine & Science in Sports & Exercise. 28(10): 1327–30. doi:10.1097/00005768-199610000-00018
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