If you want to quickly burn fat (not muscle), without long grueling cardio sessions, then we suggest you learn more about what high-intensity interval training (HIIT) is. You may have already heard about it and its almost magical ability to burn fat. That you can exercise just a few minutes a day and watch the fat melt away right before your eyes. Actually this is not true. High-intensity interval training (HIIT) is not the only tool for burning fat reserves, but if used correctly, HIIT can be a powerful tool in the fight against excess weight. And we will talk about this in this article.
What is high-intensity training (and what is it not)?
High-intensity interval training, or HIIT for short, is, in a nutshell, a style of training where you alternate between periods of (near) maximum and low intensity.
Which, in fact, is described in the title.
High-intensity intervals push the body to the edge of its metabolic capacity (basically your maximum), while low-intensity intervals allow you to recover (to catch your breath).
Most likely, you already knew this, but you probably still have questions, such as...
- How “intense” should active intervals be? How strong and for how long should they be held?
- How exactly do rest intervals work?
- How long should workouts last to burn fat?
- How often should you train like this?
And how, in principle, can you engage in intensive training on your own as effectively as possible and schedule a regimen in general?
Let's find out!
Duration of HIIT workout
HIIT exercises should be kept short. Make sure that even the longest one does not exceed 30 minutes. If you prefer longer loads, still introduce elements of high-intensity training into them.
For example, while jogging in the park, do a few bursts of acceleration for 200 meters, or pedal at maximum speed for 40 seconds while riding a bicycle. High intensity has been proven to help burn fat.
HIIT Basics
- Combine periods of high-intensity cardio (80-90% of your maximum heart rate) with periods of low-intensity cardio (up to 60% of your maximum heart rate) or periods of rest.
- High-intensity strength training should last no more than 25 minutes.
- Gradually increase the duration of high-intensity intervals and decrease the duration of low-intensity intervals.
- Do HIIT workouts 2-6 times a week depending on your fat loss goals.
HIIT Training Tips
- If you do cardio and strength training at the same time, save the cardio for the end of the workout.
- You can perform such workouts in the morning on an empty stomach, after drinking 30 g of protein.
- For high-intensity sets, choose the heaviest exercise option, such as a stair-climbing machine.
- When training outdoors, alternate between fast sprints and gentle jogging or resting.
How intense should the active intervals be?
If you look at the scientific research surrounding high-intensity training, you will notice that they often mention something called VO2 max.
Your body's VO2 max is a measure of the maximum amount of oxygen the body can use and is a major factor in determining your endurance level.
He refers to HIIT as follows:
Research shows that to get the most benefit from interval training, you need to reach 80-100% of your VO2max during the active interval.
And this is all great, of course, but not very applicable in practice, because it is quite difficult to estimate your VO2max directly during an interval training exercise. Simply because there are no reliable indicators that would allow you to accurately determine anything.
Fortunately, you can work with a more practical parameter: Vmax.
In short, you've reached the Vmax level of exertion where you feel like you can't inhale as much air as your body requires (if you can easily carry on a conversation while exercising, you're not even close).
For most people, this is about 90% of their maximum effort.
- Your goal during intense periods is to reach and maintain your Vmax.
In other words, you need to move fast enough and for long enough that breathing becomes difficult, and also maintain this speed for a certain period of time.
As you may have guessed, this requires significant effort. It's like sprinting, not jogging.
- Throughout your workout, your goal is to methodically achieve and maintain your maximum tension level.
This seems obvious, but it requires focus because the amount of time you spend at your maximum effort level determines the overall effectiveness of your interval training.
So a metabolic workout where you've been at max for, say, a minute will be much less effective than if you've pushed that up to just a few minutes.
Fortunately, this is more a matter of well-designed exercises than the need to bend rebar by force of will.
We'll talk about the exercise routine soon, and if you still have doubts, here's a motivation for you.
So here's a quick guide to interval training.
Let's look at why you should choose these types of workouts over easier, less intimidating forms of cardio.
What is HIIT
This is an embodiment in which maximum loads alternate with very light loads.
That's why the name is like that. High-intensity intervals push the body to its metabolic limit (with all its might), and during low-intensity pauses recovery occurs (normalization of breathing).
Most likely, you were already familiar with this information, so let’s discuss more specific questions:
- How “intense” should your workout be?
- How hard and for how long should you push yourself?
- What exactly should the rest periods be?
- How long should an entire HIIT workout last?
- How often should you do HIIT?
- How to get the most out of high-intensity interval training and how to add it to your daily schedule?
How “intense” should HIIT be?
If you look at scientific research on high-intensity interval training, you pay attention to such a thing as VO2 max.
What it is? This is the maximum amount of O2 (oxygen) that the human body can use while working at its limits. The overall endurance of the athlete depends on it.
Its implications for HIIT are as follows:
Research shows that you need to reach eighty to one hundred percent of your VO2 during high-intensity interval training to get the maximum benefit from HIIT.
Now we know this, but it is extremely difficult to put it into practice. There are no reliable measurements to determine VO2 max during exercise.
Fortunately, there is another, more useful measurement: V max.
How to determine that you have reached V max. When you have reached a level of stress where you cannot deliver enough air into your body (if you can talk calmly, then you have not reached this level).
For most people, this is about 90% of maximal effort.
- Your goal during periods of high intensity is to achieve and maintain V max.
That is, you need to perform the exercise quickly and long enough for your breathing to become difficult (difficult).
Then you need to maintain this intensity for a certain time. As you can see, this is hard work. This means sprinting, not jogging.
- Your goal during HIIT training is to achieve and maintain this state repeatedly.
This may seem obvious, but it needs to be emphasized because the total amount of time you spend at the Vmax level determines the overall effectiveness of the HIIT workout.
Intense workouts and fat burning
Most cardio machines have nifty indicators that tell you to keep your heart rate in the fat-burning zone.
If you do this, you are thought to be maximizing the amount of fat you burn during exercise, as opposed to sugar.
There is a grain of truth in this.
During exercise, you burn both fat and carbohydrates, and the proportions burned vary depending on the intensity of the exercise.
However, research shows that as exercise intensity increases, muscles rely more on glycogen than on fat stores.
This means that the more intensely you exercise, the greater the proportion of energy produced from glycogen stores, and not from fat.
This is why low-intensity activities like walking have a greater impact on fat stores, while high-intensity sprints hit carbohydrate (glycogen) sources more.
Here are the main reasons why many people think low-intensity steady state cardio is best for losing weight by burning fat.
Many studies, such as those conducted by Laval University, East Tennessee State University, Baylor College of Medicine and the University of New South Wales, however, say otherwise.
Specifically, they show that shorter interval training sessions for weight loss lead to greater fat loss over time than longer, low-intensity sessions.
What does this give?
Well, let's start with the obvious: the total number of calories burned during exercise.
High-intensity exercise burns more calories than low-intensity exercise, and since fat loss is dictated by energy balance, the benefit is clear.
Let's imagine that you run several times a week and burn about 200 calories per run, of which about 100 come from fat stores.
When combined with a proper calorie deficit, these workouts will help you lose weight faster.
Better, however, would be an intense workout of equal duration that burns, say, 400 calories per session, with 150 of those coming from fat stores.
Regardless of diet, the weight loss workout that burns the most energy will result in the most fat loss, and you'll lose weight the fastest.
But energy expenditure during exercise alone does not fully explain why high-intensity training is better for weight loss.
A study conducted by the University of Western Ontario gives us an idea of how effective they really are.
The researchers had 10 men and 10 women exercise 3 times a week, one group doing 4 to 6 30-second sprints (with 4 to 6 minutes rest in between), the other doing slow cardio (running on a treadmill " magical" weight loss zone at 65% VO2 max).
What was the performance?
After 6 weeks of training, subjects who did interval training lost more fat.
Yes, 4-6 30-second sprints burn more fat than 60 minutes of walking on an incline treadmill.
Scientists do not yet know the exact mechanism that makes HIIT training so effective, but they have identified several important factors:
- Increased metabolic rate for 24 hours after the program.
- Increased sensitivity to insulin in muscles.
- Higher levels of fat oxidation in muscles.
- Significant jumps in growth hormone levels (which helps with weight loss) and catecholamine levels (a substance produced by the body to mobilize and burn stored fat). Post-exercise appetite suppression.
- Suppressing appetite after exercise.
- And so on…
The answer from science is clear: if your goal is to burn the most fat in the least amount of time, HIIT is your choice.
Oxygen consumption and calorie burning
According to scientific research, it takes about five calories to consume 1 liter of oxygen.
As HIIT programs alternate between short bursts of intense exercise and moderate to low intensity exercise, researchers around the world are trying to figure out how to get more with less.
After extensive research into the effectiveness and efficiency of HIIT compared to monotonous workouts, it has been found that you can achieve comparable or greater results in less time using this method.
One study from the scientific journal Applied Physiology, Nutrition and Metabolism found that high-intensity interval training increases the metabolic activity of fats and carbohydrates in human skeletal muscle, without long sessions in the gym.
This means that the body successfully converts carbohydrates and fats into energy to fuel muscles. In simpler words, it is effective for fat burning.
The American authority on sports medicine, the American College of Sports Medicine (ACSM), states that HIIT provides the same fitness benefits as continuous aerobic endurance exercise, but in a shorter period of time.
They elaborated, commenting, "This is because high-intensity interval training tends to burn more calories, especially post-workout, than traditional long-term, steady-state exercise."
If there's one mystery or secret to HIIT, it's the calorie burn that comes with it.
Indeed, at this moment the full effectiveness and efficiency of this method is revealed.
By exercising intensely with minimal rest periods, you successfully kick-start your metabolism for several hours after your workout.
The professional term for this effect is EPOC or excess post-exercise oxygen consumption.
This means the body is working hard and it will take several hours and additional energy (calories!) for the body to return to its pre-workout state.
The exact amount of time your body burns calories at a higher level depends on the intensity and duration of the activity. Various studies have been conducted with a wide range of figures.
Some believe this occurs within 2 hours, while others have found that this effect can last for up to 48 hours after exercise.
Regardless of how many hours it actually lasts, this expenditure can add 6 to 15% more calories to your total energy expenditure.
For most women, the goal of exercise is to burn calories and lose weight/weight, but there are other benefits of HIIT.
According to the ACSM, HIIT affects:
- Aerobic and anaerobic fitness;
- Blood pressure;
- Cardiovascular diseases;
- Insulin sensitivity (which helps exercising muscles more readily use glucose as an energy source);
- Cholesterol levels;
- Abdominal fat and body weight while maintaining muscle mass.
High-intensity training and your muscles
In the minds of most people who lift weights, cardio and muscle gain are more or less opposites.
Either one or the other.
And, again, there is some truth in this, but at the same time it is a kind of simplification.
For example, research has shown that combining strength and endurance training (if you do both at the same time) can slow your strength gains and muscle growth than if you did strength training alone.
Research also suggests that the longer your cardio sessions, the more they slow down your strength and size gains.
However, this does not mean that cardio training directly interferes with muscle growth. Because it doesn't do that.
This only happens if there is too much cardio.
Cardio in the proper amount actually increases muscle growth for the reasons described here.
But what volume can be called appropriate, including for training at home?
Well, there are two factors to consider:
- Duration of individual cardio sessions.
- The total amount of cardio performed each week.
And if your goal is to improve your physique (and this requires progress in the weight zone), then cardio sessions should be short, and the average duration over the course of a week should be quite short.
Only HIIT meets these criteria and burns significant amounts of fat.
Benefits of HIIT
Taking into account the effect of HIIT training on the body and the characteristics of the technique, a number of advantages of this strategy can be identified:
- Increased metabolic rate within 24 hours of finishing your workout
- More effective fat burning compared to cardio
- Gaining Lean Muscle Mass
- Increased testosterone secretion
- The short training time and quick change of modes makes HIIT workouts less routine than cardio.
- HIIT can be done at home or outdoors without machines or other equipment.
How to Design an Effective HIIT Program
So, let's say you're ready for HIIT to burst into your life.
In order to develop a training program, you need to consider five things:
- Cardio type
- Duration of training
- Training frequency
- Duration and intensity of the active interval
- Duration and intensity of the rest interval
Let's look at each point separately.
The Best Types of HIIT Cardio
The principles of HIIT can be applied to any type of cardio, but some types are more practical (and effective) than others.
Simply put, the three best options are...
- Bike
- Rowing
- Sprint
Cycling and rowing are my favorites because sprints are sometimes hard on the legs and will likely overlap with your squats and deadlifts.
The reason I prefer these three over the others is because research shows that the type of cardio you do has a significant impact on your ability to gain strength and size gains when lifting weights.
In short, it goes like this:
The more similar a cardio exercise is to movements you use to build muscle, such as squats or barbell rows, the less it interferes with strength and size gains.
This makes sense because one of the most important parts of building strength is simply repeating a movement. (The more you do this movement, the better you will get.)
Still, if you don’t know how or don’t like to ride a bike, row or run sprints, don’t be “afraid” of other forms of cardio exercise, such as swimming, jumping rope, calisthenics, boxing, short fitness, and so on. They won't harm your muscles.
Again, the biggest mistake when it comes to cardio is doing too much cardio.
How intense should the active intervals be?
The goal of HIIT is fast and hard, not slow and hard.
This means that if you use an exercise bike or rowing machine, you need to choose the right resistance for the pedals or cable so that the cardio doesn't turn into a strength exercise.
This is why the main difference between an active and a quiet interval should be speed, not resistance.
This means that you need to increase and decrease the resistance, but not at all in the same range of values in which the speed increases and decreases.
So, as you already know, the key factor in determining the effectiveness of interval training is the total number of minutes at the maximum tension level.
If you do too little at this level, it's only a semblance of true interval training; if you do too much, you'll quickly burn out.
You achieve maximum time at maximum tension level in, say, a sprint if you try to accelerate as quickly as possible.
No need to "swing". Give your all on every push from the very first second.
In terms of duration of active intervals, 50-60% of your Tmax is sufficient if your goal is fat loss and improved metabolic health.
Tmax is simply the amount of time you can spend at maximum effort before being forced to stop.
For example, if I can ride my bike at top speed for 3 minutes before I feel like my heart is going to explode, then my Tmax is 3 minutes.
So my active intervals should be around 90-120 seconds (and yes, it's hard!)
To time your intervals, you can check your Vmax (all you need is a stopwatch), or if you're new to interval training, start with 30-second active phases.
Your high-interval training should gradually become harder.
The more you do HIIT, the more your Tmax will increase. This means that the duration of your active intervals must also increase if you want them to remain as effective as possible.
As you can imagine, these workouts can be quite challenging even for experienced athletes.
There were three studies of interval training in which experienced circuit training athletes pushed themselves as hard as they could for 5 minutes (and it improved their performance). In contrast, other studies using active intervals of 2 and 1 minute in track and field athletes found that this was not enough to improve performance.
How “calm” should rest periods be?
There are two methods to make your workouts harder:
- Increase the duration of active phases.
- Reduce the duration of rest phases.
In general, I recommend for beginners to work on increasing the duration of your active intervals until you get to 50-60% of your Tmax. Only in this case do you actually do high-intensity interval training.
When you have achieved this, see for yourself where you want to go.
It seems reasonable to me to shorten the rest periods until the ratio to active is 1:1 (90 seconds of intense work followed by 90 seconds of rest, for example), and then slowly increase the duration of both active and quiet phases, maintaining the same proportion 1 :1.
Let's imagine, for example, that you start your interval training with 30-second active phases followed by a 60-second rest period (1:2 ratio).
Over time, you calculate your Tmax and ensure that your active phases are 50-60% of it, which is approximately 60 seconds. You work at this level, maintaining a 1:2 ratio (that is, your quiet intervals are 120 seconds).
As you progress, you will feel that you can do more, and, leaving the time of the active phase the same, 60 seconds, you will begin to reduce the rest period, reducing it to 90 seconds (ratio 1: 1.5).
Gradually, your body adapts and you can further reduce the rest period to 60 seconds (1:1 ratio), and when this becomes easy for you, you begin to increase both the active and quiet periods to 90 seconds.
(And so on.)
You also need to know that quiet periods should be active recovery, where you keep moving rather than freezing in place.
Research shows that active rather than passive recovery helps achieve peak speed during the intense phase and helps the body adapt to the exercise being performed.
How to use HIIT effectively?
To answer this question, calculate your maximum heart rate (HR) by subtracting your age from 220.
For example, if you are 25, your maximum heart rate would be 195. During high-intensity work, your heart rate should reach 80-90% of this figure. In other words, a 25-year-old athlete needs to work in the range of 156 to 176 beats per minute. During low-intensity exercise, heart rate should not exceed 60% of maximum (i.e., up to 117 beats per minute).
A heart rate monitor is perfect for measurements, it will make it easier for you to monitor your heart rate and track the time between intervals. However, over time, you will learn to work by feeling.
If this is your first high-intensity interval training, do twice as much as the low-intensity workout. For example, work at a high heart rate for 20 seconds, then at a low heart rate for 40 seconds. A total of 10 approaches. After eight weeks, begin increasing the duration of high-intensity intervals and decreasing the duration of low-intensity intervals. It all depends on your level of physical fitness. To enhance fat burning, you can do both intervals even longer and make them longer, up to 20.
How long should interval training last?
One of the best things about interval training is that you get a lot of bang for your buck for things that don't seem like that much of a cost. There is no more effective way to use cardio to burn fat and get in shape.
However, their disadvantage is that it is a lot of stress for the body, which means that you can overdo it.
Follow these simple rules and everything will be fine:
- Start interval training only after 2-3 minutes of light warm-up
- Perform 20-30 minutes of interval training
- Finish your workout with a 2-3 minute light cool-down.
And you're done!
There is no particular need for longer training sessions unless athletes need to improve something rather than lose weight.
If you feel like your interval training isn't as effective as you'd like, you likely need to pay attention to your interval training nutrition.
High-intensity interval training for home[edit | edit code]
Swing kettlebells or dumbbells[edit | edit code]
Exercise with a kettlebell (snatch)
A kettlebell or dumbbell is an excellent cardio “trainer” that makes you work especially the gluteus maximus and posterior thigh muscles. Research[4] has shown that the movement from the bottom of the swing to the top activates first the back muscles (50% of the maximum voluntary muscle contraction), then the abs (20-30% of the MVC), and ending with 75% of the max. MVC of the gluteal muscle. At the top point there is maximum muscle tension, at the bottom there is almost complete relaxation. Thus the exercise itself is a continuing interval. Choose a kettlebell or dumbbell weight that allows you to perform a series of swings one after the other while maintaining good form and technique.
Training:
- 5 minutes jumping rope warm-up
- 5-8 sets of 20-40 seconds of kettlebell/dumbbell swings
- 45-60 seconds rest between sets
- 5 minutes jumping rope, cool down
- + stretching
Sprints[edit | edit code]
Sprinters have muscular buttocks and legs with a fairly low percentage of fat; this effect is achieved by activating primarily fast-twitch fibers and their microdamage. Interesting results were shown by a study by Metcalfe et al.[5] “The required minimum amount of physical activity to improve metabolism”: - 3 times a week for 10 minutes, with only 2 full sprints for 6 weeks. This training improved insulin sensitivity and glucose tolerance.
Training:
- 10 minutes of active warm-up - jumping rope, jogging, etc.
- 5 sets of 10-30 second sprints - give 155% like the last time!
- 1-3 minutes rest between sets
- 10 minutes of active cool-down, completing the training with walking.
- + stretching
Pulling a weight, wheel or sled in a shock-absorbing harness (“sled pull”)[edit | edit code]
Sled Pull
This amazing method is widely used in many types of training from CrossFit and Strongman to elite athletes in all sports. Usually a weight and a “harness” from a chest harness or around the waist are used. You can also use a wide rubber band (the one that helps with pull-ups on the bar) and a partner holding it from behind.
Wheel traction "sled pull"
Pulling weights specifically activates the core muscles, as well as the buttocks and thigh muscles. The exercise also forces you to keep your body straight, regardless of tension and fatigue, as the rounding of your back will immediately make itself felt and force you to stop.
This exercise strengthens the front part of the torso and, by the way, really helps to improve the deadlift, and also develops an “explosive” movement, which is important for many sports (athletics, football, etc.) Alternatively, you can push the “sleigh” in front of you, supporting yourself with your hands. Choosing the severity of the weight is based on a simple rule - if you move in all directions when pulling, the weight is too heavy. Winter is a great time to pull a loaded sled.
Training:
- 10 minutes of active warm-up - jumping rope, jogging, etc.
- 5 sets of 10-30 seconds each
- 2-3 minutes of active rest (fast walking)
- 10 minutes of active cool-down, completing the training with walking.
- + stretching
Heavy Rope Training[edit | edit code]
Training with a rope (Heavy Rope)
Initially, heavy rope was used for training football players (American football) and in MMA martial arts. HIIT with a rope is a great alternative for doing cardio without active participation of the legs! At the same time, this training develops strength and power, strengthens the arms, torso and back muscles - stabilizers. Basic movements - wave, throws, etc.
How often should you do interval training?
The total duration of interval training per week depends on your immediate goals and what other exercises you do.
If you want to lose weight quickly, you don't need to exercise more than 4-7 hours a week, and ideally it's better to do weight training than cardio.
For example, my training and diet programs for both men and women require only 3 to 5 hours of weights and 1 to 2 hours of interval training per week.
This way you will lose fat but not muscle and maintain a healthy metabolism.
What about nutritional supplements?
I saved this for last because, frankly, it's much less important than proper diet and exercise.
The fact is that it is not supplements that will give you a good physique - it is persistence, proper training and a healthy diet that will.
Unfortunately, the plague of the supplement industry is pseudoscience, hype about nonsense, misleading advertising, big name promotion of dubious products, junk products, products missing key ingredients, and a host of other similar shenanigans.
Most supplement companies make cheap duds and try to fool you with crazy marketing claims, celebrity names (which cost them a lot), supposed scientific babble, fancy proprietary formula names, and flashy packaging.
So while supplements don't play a key role in muscle growth and fat loss, and many of them will just be a waste of money... some of the right ones can still help.
The bottom line is that there are safe natural substances and science has proven that they are useful in increasing strength, endurance, muscle growth, weight loss and so on.
Part of my job is to know what these substances are and to find products that contain them so that I can use them myself and recommend them to others.
However, finding a high-quality, effective product at a fair price has always been a challenge.
But for the purposes of this article, let's quickly run through the supplements that will help you get the most out of your interval training and make your weight loss efforts more effective overall.
Caffeine
Since weight loss comes down to the ratio of calories consumed to calories expended, caffeine helps you lose fat by increasing your body's daily energy expenditure.
Caffeine also promotes muscle endurance, strength, improves anaerobic performance, and also relieves the “morning sickness” known to many people who lift weights.
In order to maximize the fat-burning effect of caffeine, you need to prevent the body from getting used to it. And the best way to do this, of course, is not to abuse it.
Here's what I recommend:
Before training, take 3-6 mg of caffeine per kilogram of body weight. If you are unsure about your sensitivity to caffeine, start with 3 mg/kg and increase the dose as needed.
Let your daily dose not exceed 6 mg per kilogram of body weight. There is no need to take 6 mg/kg before training and then drink several cups of coffee throughout the day.
There should be 1-2 days per week with reduced caffeine consumption and 1 day without caffeine at all. On such days, the dose should be half your norm, and a no-caffeine day means no more than 50 mg (you can drink one or two cups of tea, but no coffee, caffeine tablets, etc.)
Interval and strength training, taking fat burning supplements
Before we wrap up the topic, I want to quickly show you how it all works together and how to make this a powerful fat loss regimen. This is exactly what I do when I'm drying and it really works.
If you want optimal results, you should do weight training 5 times a week, and interval training 3-4 times, 25 minutes per set.
Here's what your workout and supplement regimen looks like:
Before the power ones:
I wake up, drink water and get ready for weight training. I have about 15 minutes to go, so before leaving I take:
- BCAAs
- Pre-workout complex
- Fat burner
Then I lift weights for 45-60 minutes and after that I have my first meal of the day, which contains about 40 grams of protein and 100 grams of carbohydrates.
Dinner:
My lunch is a light salad with chicken and balsamic vinegar as a dressing. I do this to keep my insulin levels at baseline until 5:30 pm for fast cardio.
If I ate a larger lunch with, say, 40 grams of protein, 60 grams of carbohydrates and 20 grams of fat, my insulin levels would be higher by 5:30.
I don't take any fat loss supplements at lunch.
Around 5:30 pm, before cardio
About 15 minutes before ultra-intense cardio I take:
- Fat burner
- Pre-workout complex
I then do 25 minutes of intense exercise on a stationary bike, after which I eat about 30 grams of protein.
If you combine the above scheme with the right weight loss diet, you will lose fat very quickly.
Benefits of HIIT
Reduction of body fat
According to a 2012 study, HIIT may reduce body fat more than long-term forms of exercise such as jogging.
The study examined the effects of HIIT on 46 overweight men. Participants, with an average age of 25 years, took part in three 20-minute HIIT sessions per week. After 12 weeks, the exercise group showed a decrease in abdominal fat compared to the control group.
Improved cardiovascular and metabolic health
HIIT may improve heart health in people with cardiovascular disease. Exercise can also improve indicators of metabolic health, including blood pressure, blood sugar and cholesterol. A 2015 study found that a 10-week training program provided cardiovascular and metabolic benefits that were similar to moderate-intensity training. In the study, 90 participants who were previously physically inactive did either HIIT or a traditional moderate-intensity workout. Total exercise time was 55 minutes per week for the HIIT program, and 128 minutes per week for moderate intensity.
Improved mental health
While all exercise can provide mental health benefits, HIIT can be especially beneficial. The authors of a 2021 review suggest that HIIT may provide a range of benefits for people with mental illness, including reducing the severity of depression.
A 2015 study examined the effects of HIIT on people with chronic schizophrenia. The study found that many people with mental disorders had low motivation to exercise and felt that exercise took up too much time. Short workouts can help overcome difficulties with motivation and find time to exercise. The program consisted of three workouts per week, each lasting 15 minutes with a 5-minute warm-up. Of the 20 participants, 18 completed the program. The results showed the following mental and physical improvements:
- decreased body mass index (BMI)
- decreased heart rate at rest
- lower pulse pressure
- weight loss
- improved mental health outcomes, including decreased levels of depression and social avoidance.
Despite the benefits of exercise, not everyone is able to commit to regular exercise. One of the most common obstacles is lack of time. HIIT is an effective way to exercise that can be a good choice for people who find it difficult to fit physical activity into their schedule. According to a 2014 study, exercising for just 30 minutes three times a week can be a beneficial solution. Researchers have found that each of these 30-minute workouts only needs to include 10 minutes of intense exercise for a person to experience the following benefits:
- improved heart and lung health
- improved metabolic health, which includes cholesterol and blood pressure levels
- increased oxygen supply to muscles
- improved exercise tolerance, which is how well the heart responds to exercise
Researchers found benefits after just a few weeks in both healthy participants and those with cardiovascular and metabolic diseases.
