High Intensity Interval Training (HIIT) has been getting the thumbs up from the chaps in white coats a lot recently, with numerous studies hailing it as the most effective and efficient form of exercise1.
According to the scientists, HIIT sounds like the perfect solution for time short, busy individuals – Just a few minutes per week, they say, can produce equal, if not greater results than more traditional, longer duration, moderate intensity workouts.
The science shows that with just 2 or 3 short workouts per week (usually around the 10 minute mark), one can significantly reduce your risk factors for CVD, strengthen and improve function of arteries, and increase blood flow and nutrient uptake in the muscles. HIIT has even been shown to be more effective than steady state training for fat burning.
So what does this mean for your training?
Should all your activity be kept to short and intense intervals? Should every movement you make be performed at maximum intensity to turn your body into a metabolic fat burning inferno? This is certainly the premise upon which many popular fitness methods are based.
HIIT certainly has its place in Primal Fitness 2.0. I think it is also important to realise that HIIT has limitations, however, and that you can also have too much of a good thing.
The majority of research into HIIT has been done using stationary cycling, with a couple of short bouts of exercise per week. Many of the HIIT programs you come across on the internet however, involve using a variety of different movements including complex motor patterns such as Olympic Lifting, with frequencies as high as three days on, one day off.
There are two problems with this method of applying HIIT:
1. The dose is too high.
Like High Intensity Resistance Training, the HIIT’s powerful stimulus promotes an adaptive response from the body. Like any other form of training, this stimulus is actually an acute form of stress. Get the dose right, and this acute stress will have a beneficial effect through hormesis. Overdose by doing too much though, and your body will not be able to recover sufficiently and you will eventually succumb to the effects of chronic over training.
2. The Movements are too Complex
There are a couple of problems with using complex movements such as Olympic lifts, gymnastics moves, and even natural movements such as swimming and running for HIIT.
In order to get the full benefits of HIIT it is necessary to push yourself to the limit. This is fine on an exercise bike or rowing machine, or with a basic bodyweight move such as a burpee or squat jump, but with a complex move such as a clean or snatch you would be putting yourself at serious risk of an injury. The first rule of any training program should always be don’t get injured!
Learning Faulty Movement Patterns
In Part I of this series I highlighted the fact that a large component of any movement is skill based. To be proficient at a skill you must practice it over and over again with care and precision. Performing lots of intervals under fatigue with bad technique will lead to sloppy form that will detract from your efficiency, and therefore performance, at that movement.
Although in Part I the focus was on strength based movements, this same principle applies to more endurance based activities such as running and swimming. Although there can be a time and a place for HIIT using such movements, which I will come to shortly, one should avoid performing them in such a way that your technique becomes affected by fatigue.
So how should HIIT interval training be implemented into your training regimen?
I would recommend the following:
Include one or two sessions of HIIT per week at the end of your Primal Minimalist Training Program.
Select a full body, low skill exercise such as an airdyn bike, rowing machine or burpee.
Keep a work to rest ratio between 2:1 and 1:2, with a total work time of under 10 minutes. For example 20s:10s x 8 (Tabata), 30s:15s x 6 or 30s:60s x 5.
Ensure that during the work period your are going all out, one hundred percent effort.
Performing intervals in this manner will have a positive effect on your metabolism, increase your fat burning potential (though bear in mind due to the short duration you won’t actually burn much fat), and have a positive effect on your health and well-being.
Primal Fitness 2.0 is about much more than simply postponing the inevitable however. HIIT might prevent the onset of disease, and may even promote longevity, but it won’t necessarily improve your performance at Primal activities such as running or swimming, despite the fact that science shows it will increase numerous markers of both anaerobic and aerobic fitness.
This is due to the high skill component of all these movements. In exactly the same way that a well implemented HIT resistance program can increase your potential for strength and power based activities, HIIT can increase your potential for more endurance based activities.
In order to harness this power, it is necessary to practice the movement skill in question in order to become as efficient as possible. Interval training may improve the fuel supply and energy release from food in the cells, but this is worth little if this energy is then wasted through inefficient movement. Only performing HIIT sessions, and never getting out there in the wild to run, swim and navigate through the environment as fast and as far as possible, is like having a top of the range car, but leaving it sat in the garage as you don’t know how to drive it!
If you are new to Primal movements, such as efficient barefoot running technique (i.e. POSE), or streamlined, slippery swimming (i.e. Total Immersion), then these techniques should always be practised mindfully, at low to moderate intensity, ensuring one hundred percent focus on technique at all times.
Once you are more practised, and efficient technique has started to become second nature, only then can it be useful to add carefully programmed HIIT sessions into your regimen in order to improve your speed over short distances. Use shorter work to rest periods however, such as 1:4 or more in order to ensure full recovery between repeats, so that perfect technique is maintained at all times.
So that is my Primal perspective on HIIT – Good in small doses using the right tools, but not the be all and end all and certainly no substitute for spending long periods of time out in the wild!