High Intensity Interval Training - HIIT. What effect does it have on our body?

HIIT - High Intensity Interval Training = high intensity interval training = effective training in a short time.

How to achieve this?

Many of us don't have the time to dedicate to improving our fitness due to lack of time.

Whether it's an excuse or a reality, there is a solution for the busy and for those who need a change from their current training.

The solution for many of us could be high-intensity interval training.

HIIT is its English acronym (High Intensity Interval Training).

It is both time and space efficient. There is no need to work out in a gym. We make do with the outdoors.

If bad weather surprises us, we can train at home.

Exercising briefly does not mean exercising little.

The essence of high-intensity interval training

This much is clear.

Exercise with high intensity in time-limited intervals.

Practically, this should be the case with every workout if we are honest and don't want to fool ourselves.

However, slightly different rules apply here.

Individual exercises are performed at fixed time intervals.

So are the breaks in between, no matter how exhausted we are.

And the rest should be active. For example, jumping rope or light lunges.

Let's get into the details.

High intensity interval training is alternating high intensity anaerobic exercise with aerobic exercise or complete rest.

These phases are timed.

For example, a phase of high intensity for 20 seconds and a phase of low intensity or complete rest for 10 seconds.

Such training does not last longer than 30 minutes.

However, let no one think that we will not exercise enough.

High intensity is essential. Staying at it all the time will really give you a hard time.

What can you read in this article?
Benefits of HIIT
Cardio training or HIIT?
EPOC effect
Performing HIIT

Benefits of High Intensity Interval Training

The high effectiveness of this training on overall body fitness is proven.

This is related to the positive effect on burning body fat and also on the cardiovascular system.

Benefits of HIIT:

• improves the condition of the cardiovascular system
• reduces the amount of visceral and abdominal body fat
• improves cognitive brain function (memory, attention, thinking, spatial orientation, expression, problem-solving skills, etc.)
• has a positive effect on insulin resistance, blood pressure and cholesterol levels
• increases VO2 max

VO2 max is actually an indicator of the body's level of endurance. It is the time it takes for the body to use the maximum amount of oxygen possible. It is given in milliliters per kilogram of body weight per minute. The higher its value, the more oxygen is getting to the muscles.

During high-intensity interval exercise, sugars are also used as an energy source. There is an increased consumption of glucose. Therefore, such training helps to better control blood glucose levels.

Last but not least, it also improves our mental state.

It is also associated with the release of endorphins, the happiness hormones.

However, the state of feeling good also comes after the first noticeable results of our efforts.

Cardio training or HIIT?

For many athletes, exercise is a way to lose weight.

For others, this activity is a way to not have to lose weight. Others keep themselves fit.

Basically, we all improve our physical fitness through regular training.

Cardio training, like high-intensity interval training, was not developed for the purpose of burning body fat.

It is their side effect. Better said, their legal effect.

There is no other way.

Their effect on the human body and its metabolic systems is simply to break down fat.

So why not take advantage of it?

But is cardio or HIIT better?

This is a question that many of us deal with.

Especially orthodox endurance athletes who are trying to shed some pounds by running as long as possible at the intensity of aerobic metabolism.

In this way, running endurance is successfully increased. But it is possible that fat is not reduced as much.

Why is that?

Research has shown that approximately 2.5 hours of interval training induces the same biochemical reactions in our bodies as 10.5 hours of aerobic training.

What biochemical reactions?

High-intensity interval training increases the resting metabolic rate. The body consumes more oxygen after such a workout because it has suffered from a lack of oxygen during the workout. It must ensure homeostasis, the stability of the body's internal environment. It must return to normal.

The more we panted during the workout, the more oxygen the body will need afterwards to calm down.

A common example is sprinting behind a bus at a bus stop. After it, we are often out of breath, sweaty, our heart rate is high, as is our blood pressure.

Because the sprint was short and only one, we will recover from it relatively soon. The body will therefore not need as much oxygen to ensure homeostasis.

The effect of EPOC

Professionally, this phenomenon is called the EPOC effect. It is the excessive oxygen consumption after exercise, i.e. increased oxygen consumption after exercise.

The more familiar and popular name is "oxygen debt".

The greater the intensity of exercise, the longer the duration of the EPOC effect.

And this is what we are most interested in.

The body will need to return to normal after an intense workout. The resulting oxygen deficit will need to be replenished after the workout.

Homeostasis will need to be induced.

This can take several hours, during which the body is still burning calories.

To reoxygenate the blood. We've created an oxygen debt and the body has to repair it. And the calories are being lost.

Glycogen stores will need to be replenished. During heavy training, it's the primary source of energy. The body gets it back from fat stores.

Last but not least, muscle cells damaged by training will need to be repaired. The body uses fatty acids to rebuild them. Here too, a lot of energy from fat is used.

This creates new muscle cells, which leads to muscle growth. Another desirable effect of high-intensity interval training.

During HIIT, the body uses anaerobic metabolism to obtain energy. The heart rate during such training should be at 80% of our maximum heart rate. In the resting phase, it should not fall below 20%.

Cardio training is not as intense. The heart rate is around 50% of our maximum. We get energy by burning fat through aerobic metabolism.

This starts working after about 20 minutes of such activity. Therefore, cardio training should not last less than 30 minutes.

In this article you will find the formula for calculating your maximum heart rate and read more about cardio training.

This is actually the basic difference between the two types of training.

What heart rate are you aiming for? Calculating heart rate...

Calculator and more information:
Calculator: target heart rate, heart rate zones and training intensity

High-intensity interval training has its drawbacks, however.

It is mostly designed for experienced athletes.

However, its exercise variability or exercise intensity is great. Both can be adapted to each person's fitness level.

However, people suffering from any ailment should consult their doctor first.

Another disadvantage is the high possibility of overtraining.

The exercises need to be changed frequently.

One should beware of the possibility of injury.

However, with the advent of HIIT, cardio training should not be forgotten.

Research has shown that there is not such a significant difference between the two in terms of the resulting effect.

What has the research shown?

Longer duration and intense workouts increase EPOC values more than short and less intense physical activities.

However, this does not mean that it is wise to waste energy with unnecessarily long interval training sessions. Especially not at an intensity that we cannot repeat in the next set of exercises. Even if the EPOC value is higher after interval training than after endurance training, it is only a small part of the total energy consumed. We use more energy through physical activity alone.

It is best to alternate interval training with endurance training and choose the intensity according to our training level.

It has been found that the highest values of EPOC occur during eccentric training. In this, the emphasis is on performing slow movements against gravity during each exercise. By doing so, we are actually braking either our own weight or the weight of the weights against gravity. Such a movement can take up to 4 seconds, with a rest phase between repetitions equal to 0 seconds.

This is a fairly strenuous activity. However, research has confirmed that it is best for muscle hypertrophy, i.e. muscle growth.

HIIT can slightly reduce the amount of subcutaneous fat in lean individuals, but significantly in overweight people. In particular, interval running is very useful in breaking down abdominal and visceral fat mass. That is, that which is located in the abdominal cavity and protects its internal organs.

The EPOC or fat burning values after training are also greatly influenced by the training itself.

Less fit athletes are more susceptible to more muscle damage. This places greater demands on their recovery. They also take longer to return to a resting state after exercise.

Therefore, we should choose the intensity and volume of training according to our own level of fitness.

Performing HIIT

There are different ways of high-intensity interval training.

Peter Coe's regimen

It was invented by athletic coach Peter Coe for his son Sebastian Coe (the current president of world athletics). It consisted of repeated fast runs of 200 meters with 30-second breaks. It must have been quite effective because he became a double Olympic champion in the 1500 meters.

Gibala's regimen

This is the system of Professor Martin Gibala and his team at McMaster University in Canada.

It uses a three-minute stretch to warm up. This is followed by 60 seconds of intense exercise up to 95% VO2 max, followed by 75 seconds of rest.

This is repeated for 8 to 12 cycles or sets.

Using this method 3 times per week, results were similar to training at 50 to 70% VO2 max intensity 5 times per week.

Zuniga regimen

Jorge Zuniga, assistant professor of exercise science at Creighton University, found the following.

Interval exercise at an intensity of 90% VO2 max in 30-second bursts followed by 30-second breaks allows for the best VO2 consumption as well as the longest duration of training at a given intensity.

Thus, he wanted to place the most volume and intensity of training in the shortest time period.

One cycle lasts 3 minutes.

When repeating the system 2 times a week, the exercisers showed significant improvement over previous results.

Tabata regimen

This version of high-intensity interval training was created in 1996 by Professor Izumi Tabata.

He applied it to a group of Olympic speed skaters.

The training consisted of 20 seconds of interval exercise to 170% VO2 max and 10 seconds of rest.

It was performed on a stationary bike.

It was repeated for 8 cycles for 4 minutes.

One group trained with this method 4 times per week, the other 5 times in steady state aerobic condition.

The whole study lasted 6 weeks.

At the end, the group exercising with the Tabata method had comparable improvements in endurance as the other group.

However, the difference was that the Tabata workout lasted 4 minutes and the aerobic workout lasted 60 minutes.

In addition, the first group also achieved improvement in anaerobic capacity.

This article will tell you more about tabata training.

What should high intensity interval training look like?

First of all, we need to realize that we don't want to destroy ourselves.

It really doesn't matter if we are at the level of a professional athlete or not.

We shouldn't do HIIT more than 2 or 3 times a week.

Recovery is an important factor. If we allow ourselves enough rest, we will be able to complete the next workout with maximum intensity.

This is very important with HIIT.

For example, we can train as in tabata in 8 cycles.

For example, we can arrange these into one-minute intervals in which we determine the exercise phase and the rest phase.

However, we have to be careful here.

Unnecessarily long exercise phases with short rest intervals are counterproductive. In fact, they won't even increase our performance. We will get into a state where our performance will decrease as the cycles go on and we won't be able to exercise at 100% of our VO2 max or simply work to our full potential. The point of HIIT will be lost.

The advantage is that we can divide these intervals according to our performance.

It can easily be 10 seconds of interval exercise and 50 seconds of rest. The important thing is that we exercise to our full potential. Over time, the intervals of exercise will get longer and the breaks shorter.

Even then, however, the above applies. The important thing is to increase the intensity of the exercise, not the volume.

Even if we are already trained, we do not unnecessarily lengthen the exercise phase to, for example, 45 seconds and shorten the rest phase to 15 seconds.

Then we need to increase the intensity of the exercise during this period of time.

For example, we can exercise for 30 seconds and rest for 30 seconds, or exercise for 20 seconds and rest for 20 seconds.

What exercises can be used in HIIT?

Any exercise we can think of.

The best exercises to use are bodyweight exercises or sprints.

We can use a stationary bike, treadmill, airbike and similar equipment.

We can choose, for example, running up stairs, sprints, classic push-ups, squats, lunges, lunges, pull-ups, trapeze bars, various abdominal exercises and more.

We can focus on just one exercise in each cycle, for example 8 sprints in 8 minutes.

However, we can also choose to do eight different exercises per cycle. In each of the eight intervals, we will practice a different exercise.

We can then repeat the cycle, possibly several times.

However, the entire workout should not take more than 20 to 30 minutes.

For interest, you can calculate the amount of calories for a particular physical activity:

MET Calculator Calories burned by physical activity