Whether you’re just starting to get into fitness or you’ve been in the working out for a while, you’ve probably heard of high-intensity interval traning (HIIT).
But what is it exactly, and why might it be beneficial you incorporate it into your workouts?
My goal is to provide you with enough information so that you can answer these questions and more.
What is HIIT?
High-intensity interval training is a technique where you put forth one hundred percent of your effort through quick, intense intervals.
Following this, you will enter a temporary recovery period where you move at a much slower speed.
For example, if you’re using the treadmill and you want to do a HIIT workout, you would run at a speed of let’s say, 7.5 for a minute, and then enter your recovery at the speed of 3.5 for 2 minutes.
You will continue to do this for 20-30 minutes.
During a HIIT workout your heart rate raises and burns more fat in a shorter period of time.
When you burn calories even once you complete a workout it’s called excess post-exercise oxygen consumption.
Following a HIIT session, EPOC remains elevated as the working muscle cells restore physiological and metabolic factors in the cell to pre-exercise levels.
Traditional cardio cannot accomplish this.
A review article that was published in the Journal of Sports Sciences noted that exercise-intensity studies indicate higher EPOC values with HIIT training when compared to low- to moderate-intensity steady-paced cardiovascular training.
It doesn’t take long for the benefits to kick in.
The Benefits of Doing HIIT
Here are some of the benefits of HIIT:
HIIT Increases Metabolism
When you complete a HIIT workout, your metabolism boosts for 48 hours.
You know what that means.
You’re still burning fat even though you’ve left the gym.
HIIT can increase the production of your human growth hormone up to the whole day once you’ve completed your workout.
Also, it has been known to slow down the aging process.
You’ll be looking and feeling younger on both the inside and out.
If you’re unsure how HIIT makes a difference, you’ll first have to understand the relationship with calories and macronutrients.
When you exercise your muscles need more oxygen, so you’ll need to increase your breathing.
For roughly ever liter of oxygen, you’ll burn through about 5 calories.
There are 3 energy metabolism systems that our bodies use depending on intensity and duration.
- One for immediate, full-force exertion (phosphocreatine)
- One for relatively high-intensity (glycolysis), but sustainable for a minute or two
- And one for lower to moderate strain that is sustainable for long periods of time (beta-oxidation).
The phosphocreatine system and glycolysis don’t need oxygen however, beta-oxidation does.
LISS Cardio mostly uses the beta-oxidation system; therefore, when you look at the calorie count on the treadmill after your 45-minute run you will see a high number such as 450.
Whereas if you have taken a look at an estimation of calories burned during weightlifting, you were probably a little confused at a number half that or less.
HIIT cardio has shown in research studies to burn more body fat than cardio.
So how can this be?
While there are many factors that may be the cause of this outcome, our best speculations point to the afterburn effect.
HIIT Is Quick and Easy
Earlier I gave an example of a HIIT workout using the treadmill.
Seems easy enough, right?
That’s because it is.
You can do HIIT workouts anywhere and almost if not all of them can be done in 30 minutes.
Example of a HIIT Workout:
- Floor Touch Squat
- Wide-to-Narrow Push-Up
- Tap Floor, Squat Jump
- Full Tuck Crunch
- Forward and Backward Lunge
- Tricep Dip and Hip Lift
- Kneel to High Skip
- Bicycle Crunch
- Bridge Scissor
- Swimming Plank
- Diagonal Squat Thrust
- Toe Touch Beetle Crunch
- Lateral Lunge to Knee Drive
- Inverted Push-Up
- Skater With Single-Leg Squat
- Vertical Leg Lift
- Plank Walkout and Punch
- Tick-Tock Squat Thrust
- Rock-Up to Single-Knee
No Need for Equipment
Save your money because guess what, you don’t need any equipment to do a HIIT workout.
You’ll just be using your bodyweight to get your heart rate up and then keeping it there.
Running, biking, jump roping, and rowing all work great for HIIT.
As well as high knees, fast feet, or anything plyometric.
For example, jumping lunges work just as well to get your heart rate up fast.
Did you know that some equipment like dumbbells can make HIIT less effective because you want the focus to be on pushing your heart to its max, not your biceps.
You Won’t Lose Muscle
If you’ve been on a diet you understand how it’s hard to not lose your muscle mass along with fat.
However, studies have shown that both weight training and HIIT workouts allow those who diet to preserve their muscle mass while ensuring most of the weight lost comes from fat stores. That’s a win/win!
It’s Good For Your Heart
It’s been said that extreme training helps build extreme results.
It can be difficult for people to push themselves to an anaerobic zone where you’ll feel your heart beating faster and faster.
It’s much easier to push yourself to that point with interval training because you have that rest interval that immediately follows that high-intensity point.
Many studies have shown the benefits of exercise for adults with cardiovascular disease, most of the research involved moderate-intensity activity.
A Norwegian study published in Circulation in 2012 examined whether high-intensity intervals were safe for older adults with serious heart problems.
Information was gathered from three cardiac rehabilitation centers where 4,846 subjects were suffering from various forms of heart disease ranging from a prior heart attack, angioplasty, coronary surgery, and heart failure.
They were all randomly assigned to either a moderate-intensity exercise program or high-intensity interval training.
Traditional Cardio vs. HIIT
Now that we’ve mentioned some of the benefits, let’s compare traditional cardio to HIIT.
Within the last 10-15 years high-intensity interval training has gained a load of momentum.
Because of this, it has come into question as to whether or not HIIT or traditional cardio is more beneficial towards a better workout and your overall health.
In 1997 a study was published (Phelain et al) which compares the post-exercise energy expenditure of two cardio workouts.
One of these was performed at a low intensity and the other was performed at a high-intensity where both burned a total of 500 calories. After 3 hours after exercise the results came in:
- 41 calories burned post exercise
- 116g of total carbohydrate oxidation
- 27.7g of total fat oxidation
- A remaining elevated oxygen consumption, indicating potential for further calorie usage albeit at a slower rate
- 22 calories burned post exercise
- 85g of total carbohydrate oxidation
- 36.9g of total fat oxidation
- No remaining elevated oxygen consumption, indicating no further calorie usage
The Downsides to HIIT
Many celebrities heighten the curiosity of HIIT training such as Katie Holmes and Kim Kardashian.
However, if you are not accustomed to this form of exercise you may be doing yourself more harm than good.
Experts have revealed that exhausting HIIT training can increase a person’s risk of heart disease and cancer.
In addition, these workouts can weaken your body’s ability to fight off free radicals which are harmful chemicals that alter DNA which can lead to a host of illnesses.
A study by Author, Dr. Robert Boushel, from the University of British Columbia located in Canada said:
‘If you’re new to going to the gym, participating in high-intensity “sprint” classes may increase your performance but might not be healthy for you.’
It’s been said that high-intensity workouts are able to burn up to 1,000 calories per hour.
The Federation of American Societies published some alarming findings for the Experimental Biology Journal that suggest that those new to high-intensity interval training could end up causes some serious problems for your health.
The study consisted of a dozen males from Sweden who volunteered, all of whom were in good health.
These males identified as being only moderately active. Over the course of two week, these twelve men participated in high-intensity training involving repeated 30-second all-out sprints, followed by rest periods.
The European and Canadian scientists found signs of stress in the muscles of non-athletic participants after a very intense leg and arm cycling exercises.
Also, those men had a weekend ability to fight off rogue tissues which are tied to aging and tissue damage after their workouts.
When the scientists analyzed the tissue samples from the test subjects, they found that their mitochondria were only firing at half-power after the intense training.
This reduced their ability to take in oxygen and fight off damage from free radicals.
“Our study raises questions about what the right dose and intensity of exercise for the average person really is. We need to be cautious about supporting sprint training in the general population.”
The scientist when on to explain that athletes and those who consistently workout are well-trained have built up antioxidant enzymes in their bodies to protect them against free radicals.
Dr. Boushel recommends that beginners slowly and gradually increase the intensity over a period of time, while under the supervision of a trained professional or kinesiologist.
Although the potential long-term adverse effects of high-intensity training are unknown, scientists are continuously studying the different levels of exercise to measure the dosage of training against the different biomarkers for health.