H.I.I.T - Why you've probably never actually done it.
Keypoints:
High-intensity training means you train at 85-95% of your maximum heart rate.
HIIT is for elite athletes
HIIT is short and intense. You can't sprint a marathon.
Not all exercises are suitable for HIIT.
Get fit with interval training and LISS and eventually be fit enough for HIIT.
Do strength training when you have limited time.
I'm guilty. For years, I sold simple interval training as HIIT. But in my defense: I didn't know any better... Well... actually I did, but like all of us, I got distracted by the advertising promises.
HIIT is everywhere. In magazines, on TV, on YouTube... HIIT for beginners or HIIT for abs. Burn fat fast with HIIT. And so on and so forth...
But is all this true at all? Is HIIT suitable for everyone and even for beginners? What actually makes a HIIT workout? Are there better alternatives? And how many times can you write HIIT in one paragraph without losing the reader's attention?
Let's go...
What is HIIT?
HIIT stands for High Intensity Interval Training. The principle is that you alternate between a high-intensity strain and a very short break. The best known form is TABATA by Dr. Izumi Tabata, a Japanese sports scientist. Here, 20 seconds of strain alternates with 10 seconds of rest... for 8 rounds.
Several benefits are attributed to this training method. It is considered time efficient and effective. Due to the so-called after-burn effect, you can still notice increased fat burning up to 24 hours after exercise.
Different HIIT protocols can be between 5, 10, 15 and 20 minutes long and in high performance sports even up to 30 minutes.
Sounds tempting, right?
What does high intensity mean?
In cardio training, intensity is measured by maximum heart rate. As a rough rule of thumb: 220 minus age (I said "rough"! Yes, you can subdivide by gender among other things and there are other formulas).
High-intensity is considered to be exercise in the range of 85-95%(!) of maximum heart rate. In other words, it's training at the limit of exertion.
Now what's the problem with HIIT?
Intensity vs. Effort
Many people confuse effort with intensity. But effort is completely subjective. Intensity is objective because it's tied to your heart rate in endurance training. Just because I'm sweating and can't go any faster doesn't mean the workout is high intensity. You can also collapse at a pulse of 140 and still have been far from the 85% (if your max pulse is 190).
And while you can certainly get into the 85-95% range, you would then need to be able to maintain it throughout the workout. Think you can maintain that kind of intensity for 20 minutes? Most of us simply can't! The fatigue is simply too high to sustain the frequency of the intervals at the same intensity. Elite athletes can. The one percent of the population.
Exercise selection
Most HIIT classes or HIIT workouts on Youtube use exercises that are unsuitable for getting into the right heart rate zone.
Strength exercises like push-ups, squats, planks and lunges have no place in a HIIT. They won't get you into the required heart rate zone. Strictly speaking, someone who uses strength exercises has not understood the HIIT principle.
The same applies to titles like HIIT for the abs or core or legs. You also can't train individual muscle groups this way. In fact, how could you? The point is to maximize activation of the cardiovascular system, not to create a burn in the abdominal muscles.
The best exercises are those that allow you to go full throttle without much technique failure. And as I said, even then, only elite athletes will even get into the right heart rate zone.
Good exercises are:
Optimal: sprint, sled push, bike, row, airbike.
Suboptimal: high jumps, mountain climber, burpees, jumping lunges, jump rope, etc.
Workout duration
I already mentioned that a HIIT can be 5, 10, 15 or even 20 minutes long for us ordinary people. There are 60-minute HIIT workouts on YouTube. That would mean, at my age I would have to endure 60 minutes with a pulse of 170... Take your phone and dial “91” and when I collapse add "1"!
Remember: Intense training, by definition, can't last long. You can't sprint a marathon.
Fun Fact: The average marathoner with a finish time under 2h10min can maintain 20km/h for the entire marathon.
So what's the consequence?
Of course, if you enjoy these workouts, you can just keep doing them. Any exercise is better than none and you will certainly achieve some fitness. But you should keep in mind that you won't have the promises of HIIT.
If you absolutely want to train at 85-95% of your maximum heart rate (there are people out there who like to suffer), then the first step would be to make the right exercise selection. And then you train this. And not once and next time something else, but several times. Weeks. For a whole training phase. At first (and maybe never) you won't be able to get into the heart rate zone. This is still no HIIT, it is " just" interval training, but you will get better. And as you get better, you may eventually be so fit that you can not only reach the heart rate, but also maintain it.
Important: High intensity also means a high level of resource consumption.
You will need more recovery; more sleep, more focus on nutrition, more protein, more micronutrients, and more.
High intensity is demanding. The chance of getting injured is higher than with so-called low-impact variations.
The opposite of HIIT is LISS (Low Impact Steady State). I'll write more about LISS and the benefits of Zone 2 training another time. Only so much:
LISS
low impact on your body
30-60 Minutes
great for fat loss
HIIT
more preservation of muscles (in contrast to LISS)
10-30 Min
great for fat loss
Do strength training when you have limited time.
If the most important point of HIIT for you is saving time, then you should consider that strength training has the biggest bang for your buck. It doesn't even have to be an hour of training. Go to the gym, warm up with squats, and then do a simple 5x5 of squats. That will be about 20 minutes as well. Do that for half a year and you will have a formidable squat.
...This also works with other full body exercises like bench presses, deadlifts, chin-ups😉
Ciao,
Marco
