High-intensity interval training is currently a very popular trend in the fitness world. It significantly reduces workout time, effectively trains both the heart and muscles, and, according to scientists, is one of the best exercises for weight loss. In this article, we will discuss why they are so popular, what makes them even more effective for weight loss and health compared to traditional long-duration cardio exercises (running, swimming, cycling), and we will teach you how to perform them correctly.
Main thoughts:
Today, as always, there is still a widespread belief that the time spent in the gym (on a treadmill, stepper, or bike) is proportional to the speed of weight loss.
But this is a layman’s opinion.
Scientists think differently. They say the following:
1. First, traditional physical exercises for weight loss (running, swimming, cycling, walking) – ARE NOT effective in burning fat, as a very small number of calories are expended during a standard workout. The most important factor for weight loss is a proper diet and activation of the internal metabolism, which accounts for about 70% of daily calorie expenditure. For more details, see our material:
Recommended: What you need to do to lose weight or Why a proper diet is more important than exercise
Secondly, there are exercises that are much more effective for weight loss and overall health, as they activate the internal metabolism and require significantly less time to perform. We are talking about high-intensity interval training. Let’s discuss it.
What is High-Intensity Interval Training?
HIIT (High Intensity Interval Training) – High-Intensity Interval Training is a type of workout where exercises for various muscle groups are performed very intensely, with short rest periods in between.
They combine strength exercises and aerobic exercises, equally training both the cardiovascular system and the muscles.
Interval training has gained immense popularity in the fitness world, which continues to grow among both amateurs and professionals.
In fact, they are not something entirely new: since the beginning of human history, people have lived in a rhythm of intense training, simply calling it by another name – survival. Bright examples include hunting, wars, and disputes between males, where a quick burst of energy was required, followed by rest in the form of glory, delicious food… or death 😉
According to scientists, our bodies may be programmed to respond to this type of physical activity. But since the times of survival are in the past, today interval training is a quality model of ideal exercises for our bodies, representatives of a generally problematic, sick, and crooked last stage of evolution – the sedentary human.
The colossal advantages of interval training are that:
- they can be performed almost anywhere;
- they take significantly less time than traditional workouts like gym sessions, running, walking, swimming, or cycling, yet their effect is much stronger;
- Scientists claim that high-intensity interval training is the best exercise for weight loss.
- They are also significantly more beneficial for overall health and brain health in particular.
For those who are unaware, this type of training may seem too trivial (for girls and elderly people), but believe me, it is not.
I have been regularly engaged in various sports for over 15 years, but three sets of 12 exercises in interval training can literally bring me to my knees. I can guarantee any of you a similar result, regardless of your fitness level or gender 😉
High-intensity interval training is natural for humans and allows for a significant reduction in time spent in the gym, being more effective for weight loss and beneficial for health compared to traditional sports.
Recommended: How to lose belly fat and how effective are only abdominal exercises?
High-intensity interval training was created for professional athletes
Interval training was developed in response to the need for effective exercises for professional athletes to maintain their form in time-constrained conditions, such as during travel.
What was wrong with the classics like running, swimming, and gym workouts, and what was the problem?
Here’s how it is defined by the American College of Sports Medicine, which provides the following recommendations for professional athletes regarding training:
- for strength sports: 8-12 repetitions in 2-4 sets for each major muscle group;
- for aerobic sports: 150 minutes per week of moderate-intensity exercise (30-60 minutes per workout) and/or 75 minutes per week of high-intensity exercise (20-60 minutes per workout).
Furthermore, scientists from the same college note:
“It is possible that these recommendations may be effective; however, in time-constrained conditions, they are not very realistic; moreover, scientific research demonstrates their low effectiveness, even when fully adhered to.” 1
In response to this statement, researchers Brett Klika and Chris Jordan from the Human Performance Institute (as always, from America) developed a training program that combines strength exercises with aerobic ones, requires little time and can be performed anywhere, without special fitness equipment. Here’s how they described their creation 2:
“Our approach combines strength and aerobic exercises in a single workout lasting about 7 minutes. To increase the load, you can perform 2-3 sets of 7-minute exercise complexes, depending on the available time.
The only weight used is your own body weight, and you can train anywhere.
There is nothing new in high-intensity training, but it is gaining popularity today due to its effectiveness, especially in time-constrained conditions. The combination of aerobic exercises with strength training, performed at high intensity with short rest periods, provides huge health benefits in significantly less time than traditional sports for weight loss.”
High-intensity interval training effectively trains both the cardiovascular system and muscles, requires about half the time to complete compared to traditional sports, can be performed anywhere, and does not require special fitness equipment.
Recommended: What to eat to lose weight?
View
Scientifically Proven Benefits of High-Intensity Interval Training for Fat Burning
According to scientists, the ideal and natural form of physical activity for humans is a short but very intense burst of energy — a principle embedded in interval training.
In terms of effectiveness, interval training surpasses traditional cardio exercises.
Researchers Brett Klika and Chris Jordan based their intensive training program on the circuit training principle first developed in 1953 by scientists R.E. Morgan and G.T. Anderson from the University of Leeds in England.
Their program included 9 to 12 exercises performed at moderate intensity for a specific time or a certain number of repetitions.
Here’s what they noted 3:
1 High-intensity interval training is beneficial for weight loss and fat burning
During such training, all major muscles are engaged with very short rest intervals between exercises.
The aerobic nature increases oxygen delivery.
All together, this activates the speed of the internal metabolism, which is the most important “consumer” of calories in the body, through increasing the level of catecholamines. (Every day, the internal metabolism burns about 70-80% of daily calories, while physical activity accounts for only 20-30%.)
In addition to the benefits for weight loss, periodic workouts provide additional health advantages. One of them is that they stimulate the release of growth hormone – one of the most important hormones in bodybuilding and fitness, which activates muscle growth and fat burning.
In such an activated state, metabolism can remain elevated for up to 72 hours!
In one study published in the journal Cell Metabolism, it is stated that when healthy sedentary individuals begin to train intensely, changes occur in their DNA (even if the duration of the workout is short): they affect certain genes responsible for fat metabolism in the body. This is manifested, for example, in the activation of the production of enzymes responsible for fat breakdown 13.
High-intensity interval training produces genetic changes at the DNA level, resulting in increased production of enzymes that break down fat
Important: These factors, along with the increased oxygen consumption described further, make interval training the best and most effective for fat burning, even compared to traditional aerobic exercises for weight loss (running, cycling): a 20-minute high-intensity workout burns more calories than 20 minutes of steady-state aerobic exercise.
High-intensity interval training is beneficial for weight loss due to increased internal metabolism speed, stimulation of growth hormone release, and increased oxygen consumption
Recommended: The best natural fat burners and weight loss products
2 HIIT workouts are beneficial for building muscle mass
In one study published in the Journal of Obesity, it is stated that interval training over 12 weeks can not only help reduce belly fat and eliminate visceral fat but also significantly increase muscle mass and aerobic power 12.
3 High-intensity interval training increases VO2 max
VO2 max is the maximum oxygen consumption during exercise. The higher it is, the better the muscles are supplied with oxygen, the higher the performance, and the better the fat-burning effect: the amount of oxygen consumed by the body is directly related to the amount of fat burned.
This parameter is also a measure of cardiovascular endurance and fitness: professional athletes (for example, runners) have significantly higher values than ordinary people.
“High-intensity interval training also effectively (and sometimes even more so) increases maximum oxygen consumption, just like traditional aerobic sports, despite the significantly lower volume of exercises performed” 4
Interestingly, during such workouts, the effect of increased oxygen consumption continues for several hours after training, and fat burning is activated for up to 72 hours!
Each liter of inhaled oxygen burns approximately 5 calories.
During intense workouts, oxygen consumption increases, which is directly related to fat burning, activated for up to 2 days after training
4 Intensive interval training improves insulin sensitivity
Decreased insulin sensitivity is a factor associated with the development of type 2 diabetes.
Research indicates that just after two weeks of interval training, insulin sensitivity and the body’s ability to control blood sugar levels improve in healthy but sedentary individuals 14.
Paradoxically, in an experiment involving individuals with type 2 diabetes, after just one interval workout, a significant improvement in the body’s ability to control blood sugar levels was observed for the next 24 hours 15.
Intensive workouts improve the body’s ability to control blood sugar levels, which is especially beneficial for diabetics
We recommend: The harm of fat burners and side effects: what makes natural supplements dangerous?
Composition of exercises in high-intensity interval training
They can be very diverse, and recently, more and more variations are emerging (for training the upper body, lower body, full body; for strength and endurance).
Moreover, any of these variations can be further modified independently as fitness levels increase (increasing the duration of the exercise phase, shortening rest periods, upgrading a specific exercise for a particular muscle group (for example, instead of squats – dumbbell squats, jumping out of a full squat), etc.).
In the original exercise complex developed by the creators of interval training, there are 12 exercises, each performed for 30 seconds, with a 10-second rest, for a total duration of ~7 minutes. The entire complex can be repeated 1-3 times, depending on the fitness level.
The composition of exercises in a classic high-intensity interval training session:
- Jumping jacks (full body)
- Static wall sit (lower body)
- Push-ups (upper body)
- Curl-ups (abs)
- Step-ups onto a chair (full body)
- Squats (lower body)
- Tricep dips on a chair (triceps, upper body)
- Plank (abs)
- High knees running in place (full body)
- Lunges (lower body)
- Push-ups with rotation (upper body)
- Side plank
How to perform high-intensity training
The exercise complex can be repeated 1-3 times. How many times is better? It depends on several factors, including fitness level and intensity: the more intense, the shorter the overall duration of the workout should be.
Scientists have shown that even 4 minutes of HIIT exercises improve VO2max (oxygen consumption) and insulin sensitivity. However, this requires working at a very high intensity, at the limit 8, and this option is definitely not for beginners.
For maximum effect, scientists recommend an intensity level of 80-95% of maximum 9. Each person’s maximum is different, and it can be roughly estimated by when it becomes difficult to maintain your breath (almost impossible).
If we represent this in numbers on a scale from 1 to 10, a typical moderate-intensity run scores around 5-6; the intensity of high-intensity training should be at a level of 7 and above.
But all of this is general advice. What distinguishes high-intensity training is that it can be flexibly adjusted to suit individual needs. Benefits will still be present even if you reduce the intensity but slightly increase the duration of the performance (remember physics: work = intensity * time ;))
Recommended: How to lose weight without harming your health? The most important principles
In summary: what we learned about the benefits of HIIT interval training
Lack of time is the most common excuse for not exercising. High-intensity workouts solve this problem and, according to scientists, do so quite effectively.
They are beneficial for weight loss, initiating the fat-burning process (which continues for several days after the workout), strengthen all muscle groups, improve blood sugar levels, and are generally very good for health.
They require significantly less time to perform compared to traditional running, cycling, or swimming, yet they provide a definitely greater effect.
