which prevails?

This time I want write about at the moment very popular and widely used training methods - SMIT (Supramaximal Interval Training) and HIIT (High-Intensity Interval Training). I bumped into this terminology first time last summer / autumn and got very familiar with these during the trip to Florida in October. You couldn't miss noticing SMIT and HIIT even if you would have been blindfolded. I have also tried and used these training methods - during my professional career this kind of training didn't have such a fancy name.

In Finland common term for interval training is HIIT, but behind the "Great Blue Ocean" HIIT is different training method than SMIT. In this blog post I'm trying to illuminate both the differences and similarities and the benefits and possible risks that relates to interval training. At the end of the post I'm going to reveal which is better, SMIT or HIIT?

What are SMIT and HIIT?


SMIT = includes training with maximal effort certain time and the recovery if complete (total rest)

In SMIT the effectiveness of the training exceeds VO₂ max value (= aerobic capasity*). This means that the speed or power / intensity used in training exceeds the level of aerobic capasity (it can even be 175% from VO₂ max). You are then doing training anaerobically in other words without oxygen. You are getting significant amounts of lactic acid all over your body. Because of this, the recovery parts are long to maintain high quality in training. The working part is relatively short, typically from 30 to 60 seconds, but it can last even 90 seconds (quite brutal!). Work-recovery ratio is around 1:5 and 1:8 in other words 30 second work phase is followed by 3 to 5 minutes recovery (passive total rest or super low intensity recovery).

To be short, in SMIT you can do i.e. 45 seconds maximal sprint and have 4 to 6 minutes total recovery - you don't do anything, walking at most. And you repeat this from 6 to 10 times and you have completed the training!


HIIT = you do high intensity interval training and you have low or medium intensity recovery phases in between. The recovery in HIIT is so called active recovery.

HIIT is a form of interval training in which you mix hard intensive working phases (typically around 90 to 100% from VO₂ max) with less effective recovery phases (typically around 50 to 60% from VO₂ max). The length of working and recovery can vary, but the intensity of the work interval has most affect on the work-recovery ratio. If the intensity of the training is plenty below VO₂ max, work-recovery ratio can even be 5:1, in which you push yourself i.e. 50 seconds and the resting time is 10s.

Here is an example: Run 4 minutes with rapid pace (if 10 is the maximun speed / feeling / intensity), these intervals should be done with a feeling of 8). After the running part you have 4 minutes recovery while jogging. You do 6 of these and you can go home with a smiley face.

NB! You have the same rule in both training methods: The more intense interval the longer recovery time!

To whom?

SMIT and HIIT are effective and demanding training methods for active sportspersons, who want to enhance their condition and performance and capacity. Mainly because of this, I don't recommend these methods to beginners. I'm sure you'll get results and development with these methods - also beginners - but exactly because of the effectiveness and high demand intensity required the risk of injuries increases - especially with beginners. The risk of overtraining is also very common with this kind of training.

Properly used you will get phenomenal results with lactic acid tolerance and oxygen intake. To be more precise, SMIT and HIIT improves aerobic capacity (VO₂ max) and increases the ability to train closer to anaerobic threshold** (and thus burn more calories during training).

Research results

The book Fitness and Wellness, 10th ed. says that researches have shown that increasing the intensity of training is beneficial to health and exercising.¹ The research results have shown that you can increase fat burning during training by using HIIT.

It has also been shown that effective interval training improves and advances cardiac output, efficiency, oxygen transport, lactate threshold**, speed and power, fatigue resistance and exercise efficiency.

But in this, like overall in training, moderation is the key. It is not wise to build training program solely based on SMIT and / or HIIT. It is recommended that this type of training would be between 5 to 15% from the total training amount. Human body needs also aerobic training, stretching, muscle maintenance, strength and speed training, agility and skill training.


Research published in 2013 concentrated on finding endurance and speed benefits.² The researchers found that in the 3000 meters time trial SMIT improved endurance better than continuous running. Furthermore, in the speed and speed endurance training (40 meter sprint and repeated sprint ability) SMIT enabled better results than HIIT or continuous running. To sum up these researches, you can say that SMIT provides the greatest benefits for physically active individuals for concurrent improvements in endurance, speed and speed endurance.

We got familiar with SMIT and HIIT last time we had FAF International Personal Trainer -education - or at least versions of them. We had Tabata training with spinning bike (have to write about Tabata and make a video clip soon!) and speed interval training - 30 seconds work / 90 seconds recovery and this times 8. I would say that Tabata is a kind of SMIT exercise and speed intervals are like HIIT training, although these training methods don't fit to "the official definition" of SMIT and HIIT with the work-recovery ratio they have.

Lastly, I want to say that use interval training (SMIT and / or HIIT) wisely! It is very effective and training method that improves aerobic capacity rapidly. The effectiveness and intensity are the reasons why this training method is such a strenuous and lactic-acidy workout. Because of this, you have to give enough recovery time for your body so that it is able to develop and be ready for the next training session. Although interval training is excellent training method, there are no shortcuts to development. SMIT and HIIT function at their best as a small part of the complete training program to well trained sportspersons who want to have something extra to their daily routine.

You can read more about SMIT and HIIT from here: (in Finnish)

Tatu Pussila

I have used few journals in addition to the ones mentioned below while writing this blog post. I'll use more references in the future posts, if found necessary and needed!

* Aerobic capacity a.k.a. VO

  • the highest rate of oxygen consumption attainable during maximal or exhaustive exercise
  • the amount of oxygen that person can consume in maximal effort
  • the maximum volatility of oxygen that we can consume and utilize; the level in which we cannot increase oxygen intake

An example:

You run with your friend and you chat using normal full sentences (aerobic state a.k.a. with oxygen; you use oxygen in energy production). The you decide to increase running speed at the end of your route and you sprint few times. You start to use short sentences and huff and puff quite a lot. Now you have reached the anaerobic state (without oxygen; is starts to build up lactic acid into your body, when there is not enough oxygen coming into your body; body cannot remove lactic acid from the body as fast as lactic acid is building up). This is your aerobic ceiling or VO₂ max.

In the real life you can use the Talk Test. If you can speak with full sentences as in normal discussion, your training is aerobic. But if you have to take more oxygen few times during sentences, you are training anaerobically.

** Lactate threshold / Anaerobic threshold

The intensity of training increases so high, that the body produces more lactic acid than the body can transfer of remove. The lactic acid starts to build up in blood.

¹ Hoeger WWK & Hoeger SA (2013). Fitness and Wellness, 10th Edition. 352 p.
² Endurance and sprint benefits of high-intensity and supra-maximal interval training. Cicioni-Kolsky D et. al. European Journal of Sport Science. May 2013. Vol. 13. Issue 3. p 304-311.

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