If you’re looking for a physical activity that is both effective and time-efficient, you needn’t look any further than a high-intensity interval training session, otherwise known as a HIIT workout. Few training strategies will rival HIIT for challenging your anaerobic system, all while building muscle.
Sure, plenty of workouts and high-intensity training techniques will leave you gasping for breath with burning muscles — CrossFit, anyone? But HIIT deploys a unique combination of short bursts of maximum effort with relatively short (but scheduled) rest times. Everything from your work capacity to your mental stamina is likely to increase through HIIT.
Here are the biggest benefits of HIIT, from the health benefits of intense workouts to the satisfaction of crushing your fitness goals (and finally defeating your fear of burpees).
What Is HIIT?
Plainly put, HIIT is an acronym that stands for high-intensity interval training. At its core, HIIT involves periods of all-out activity, interspersed with periods of low-intensity exercise or complete rest.
In practice, a HIIT session requires you to sustain your maximum effort for a short period and to maintain the best effort possible in future rounds even as fatigue sets in.
The Original Definition of HIIT
As with other forms of exercise, different athletes and coaches take varying approaches to their HIIT programs.
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Reportedly, the first HIIT regimen to be popularized by a premiere coach was established by Peter Coe, who had his Olympian son Sebastian run a mixture of sprints in preparation for his events. Coe’s training sprints ranged from 200 to 400 meters, with short recovery times between them. (1)
The Broadened Understanding of HIIT
Since its inception, HIIT has grown to broadly encompass several other formulas of training that generally follow the same model. The much-studied Tabata, Gibala, Zuniga, and Vollaard regimens all fall beneath the broad heading of HIIT.
All four regimens intersperse periods of sprinting or max-effort work with recovery periods, with none of the workouts lasting longer than 30 minutes in total.
- Tabata: 20 seconds of high-intensity exercise; 10 seconds rest; repeated for 8 cycles (4 minutes) (2)
- Gibala: Three-minute warm-up; 60 seconds of high-intensity exercise; 75 seconds of rest; repeated for eight to 12 cycles (18 to 27 minutes) (3)
- Zuniga: 30-seconds of high-intensity exercise; repeated for 10 cycles (10 minutes) (4)
- Vollaard: 10 minutes of low-intensity exercise interspersed with two all-out 20-second sprints (5)
Some athletes suggest that any maximum effort longer than 10 or 20 seconds disqualifies a workout from being considered true HIIT. The longer you work, the lower the intensity your body can sustain.
The maximum effort you can sustain for 10 seconds is certainly faster and more intense than the max effort you can sustain for 30 seconds or a minute. Your body will pace itself accordingly. Even if you start out your 60-second sprint all out, your body will run out of readily available ATP (adenosine triphosphate), your muscles’ source of energy within the first 10 seconds or so of your max effort.
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You’ll then start drawing ATP (energy) from different energy systems. This happens regardless of fitness level, as your body can only store and produce a certain amount of ATP at a time. So are longer max efforts still HIIT? It depends on who you ask.
One thing that remains constant across HIIT workouts, however, is that they involve very intense bouts of effort sandwiched between relatively short rest periods. All told, the workouts are never very long, ranging from as fast as less than five minutes to less than 30.
Benefits of HIIT
The advantages of HIIT training are backed by plenty of research. So don’t worry: your hard work and dripping sweat is likely paying off.
Builds Muscle
No, it likely won’t be your first go-to for gaining muscle mass — that would be a strength training program well-acquainted with the principles of progressive overload. Nonetheless, HIIT can be used to develop muscle mass as well. (6)
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By employing HIIT principles to crank out explosive reps during weight training, you can build muscle and pack on a commensurate amount of power to go with it. In turn, that power and muscle mass may help you increase strength in your barbell exercises — which can boost muscle gain.
Quicker Strength Training
No matter how dedicated you are to the gains, sometimes you just don’t have a lot of time to spend in the gym. That’s when you turn to 15-minute workouts and HIIT. With this training modality, you can achieve your objectives rather quickly.
If your goal is to tax your muscles as thoroughly as possible, and as rapidly as possible, HIIT will be your go-to. You’ll allocate less time to working out without sacrificing intensity.
One of the foundational discoveries that boosted HIIT’s significance was made by Izumi Tabata. His protocol established that a basic HIIT regimen could substitute for hour-long cardiovascular training in elite cyclists on some days. (2) So when you’re pressed for time, kick up the intensity for similar gains.
Concurrent Power and Aerobic Training
Tabata’s study also showed that cyclists could maintain their peak aerobic output while spending less total time on their bikes. This means that HIIT-practicing cyclists were able to match the cardiovascular output of their peers who exclusively trained aerobically for distance, while also developing the power to outsprint them over short distances. (2)
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Athletes integrating HIIT into their training regimen became more powerful and faster and maintained their ability to train for longer distances. That’s an impressive mark for such a quick sprint workout.
Increased Mental Toughness and Confidence
You might be confident as a strength athlete, but it takes a unique kind of mental toughness to push through the rigors of HIIT training. You’ll need to break through all kinds of mental barriers when your lungs and muscles are burning and there’s no end to your workout in sight.
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If you’ve ever tackled a HIIT session during an air bike workout, you know that even 15 seconds can feel like forever. Training yourself to successfully complete a HIIT workout — even if it doesn’t feel very pretty — can give you the mental stamina and confidence boost you might need to stand up under a heavy barbell in your next workout.
Bigger Work Capacity
You might be strong, but how quickly can you recover from your biggest efforts and do the same thing over again? For powerlifters, who traditionally take long rests between sets, going heavy once might be a much easier effort than doing lightweight or bodyweight exercises for higher reps with shorter rests — like you’ll see with HIIT protocols.
That’s all about work capacity, or your body’s ability to do a certain amount of work in a given length of time. HIIT may not help you find your new one-rep max, but it can supplement your training to help improve your capacity to train with more volume without fatiguing as quickly. This boost in work capacity can help yield tremendous strength gains over time.
Burn Calories
While the calorie-burning impact of the much-touted EPOC (excess post-exercise oxygen consumption) is less significant than one might expect, HIIT protocols can still be a method of promoting fat loss.
If you’re hoping to lose fat, the shortened duration of HIIT doesn’t mean you’ll forgo a significant caloric burn. A study comparing the effects of HIIT workouts and moderate-intensity exercise on people with clinical obesity showed that both groups lost similar amounts of body fat. On top of that, the HIIT cohort enjoyed a larger increase in cardiorespiratory fitness. (7)
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For people who get bored with LISS cardio (low-intensity steady-state cardio) and would prefer faster, more explosive types of exercises during a short period, HIIT might be a better choice. That’s because athletes are more likely to stick to aerobic exercise and other types of training programs if they enjoy it. So if you enjoy HIIT, stick with it to boost your calorie burn over time.
How to Add HIIT to Your Routine
You don’t have to transform your entire workout program to incorporate HIIT. There are several ways to add HIIT to your weekly routine. This includes blending HIIT workouts with what you already have in progress — it needn’t be a case of HIIT or miss.
Add a Little at a Time
You don’t need to go all out in your program to go all out in HIIT sessions. You can begin with a few very short HIIT segments, and then either lengthen segments or add additional rounds as your endurance improves. Consider adding a brief HIIT session to the end of your training as a workout finisher.
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You needn’t bite off more than you can chew during your first HIIT workout. Start slow. Otherwise, you might leave yourself sore and reluctant to repeat the process.
Establish a HIIT Day
If you want to retain the core of your workout routine but still want to engage in HIIT protocols, you can take one day of your week and turn it into HIIT day.
Consider scheduling this training day for when you know you’ll have the shortest amount of time available to spend at the gym. That way, you can get in, exhaust your muscles rapidly, and then get out quickly.
Dispose of the Structure
Just because there are reliable HIIT workouts that can be tailored to boost your explosiveness, those aren’t the only HIIT routines that work. Workout regimens like fartlek training can permit you to loosely integrate elements of HIIT as you see fit, while also enabling you to choose the moments for sprinting more freely.
Your Takeaways
- HIIT workouts alternate short periods of max-effort explosive activity with short, scheduled recovery.
- You can apply HIIT fundamentals to cardiovascular training as well as strength training.
- There are several varieties of HIIT training that require varied lengths of work time and rest time. You can choose the workout that is most beneficial to you.
- You can integrate HIIT workouts into your training slowly and incrementally, or you can go so far as to establish specific days that are set aside exclusively for HIIT workouts.
- HIIT workouts have been proven to help distance athletes maintain their aerobic fitness with fewer total minutes spent training.
- HIIT is structured in such a way that even beginners can use HIIT as a way to raise their heart rate, gain power and muscle, and potentially facilitate weight loss if that’s a goal.
HIIT One Out of the Park
HIIT takes a lot of grit and determination, both from your mind and muscles. If you’re willing to subject your body to a few bursts of all-out effort during your training week, you can take your rest periods assured that you’ll be reaping a whole range of benefits.
Your workouts will become more time efficient, and your aerobic fitness and confidence are likely to rise. It’ll be hard work, but the benefits of HIIT give you a very favorable trade-off.
FAQs
If you still have questions about the benefits of high-intensity interval training, you’ll find several answers to those questions below.
HIIT is beneficial because it allows athletes to emphasize maximal power production during their workouts. This can also take the form of adding sprinting regimens to athletes who typically train their aerobic systems in longer, slower forms of cardio. Further, HIIT can reduce total training time for those with limited windows in which to train.
While HIIT can indeed help boost calorie burning per minute for athletes, distance running remains a more reliable calorie burner for many people. That’s because HIIT workouts are so much shorter in duration. So even if you’re burning slightly more calories per minute, your overall effort will likely yield a greater caloric output through a longer distance, steady-state run.
You’ll certainly want to consult a physician before you begin any exercise program, and that is especially true if you’re pregnant. With that being said, at least one study has suggested that performing HIIT workouts was safe for fetuses and birthing parents even into the second and third trimesters of pregnancy. (8)
The best way to do HIIT largely depends on the personal preferences of the trainee. Multiple analyses comparing forms of sprint training indicated that the differences between different HIIT workout types were negligible. (9) Therefore, your best way to do HIIT is likely to be the HIIT workout that is productive for you, and that you are willing to repeat.
In other words, choose options you enjoy doing. If you love sprinting but hate box jumps, you don’t need to get up onto a plyo box. Fans of intense efforts on a rowing machine may prefer that over picking up the pace on the treadmill. Whatever gets you excited is what you’ll likely want to choose.
References
- Seb Coe – 5 Week Training Log Before Winning 1984 Los Angeles Olympics 1500m. Retrieved on October 7, 2023.
- Tabata I, Nishimura K, Kouzaki M, Hirai Y, Ogita F, Miyachi M, Yamamoto K. Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Med Sci Sports Exerc. 1996 Oct;28(10):1327-30.
- Little JP, Safdar A, Wilkin GP, Tarnopolsky MA, Gibala MJ. A practical model of low-volume high-intensity interval training induces mitochondrial biogenesis in human skeletal muscle: potential mechanisms. J Physiol. 2010 Mar 15;588(Pt 6):1011-22.
- Zuniga, Jorge M1; Berg, Kris2; Noble, John2; Harder, Jeanette3; Chaffin, Morgan E2; Hanumanthu, Vidya S4. Physiological Responses during Interval Training with Different Intensities and Duration of Exercise. Journal of Strength and Conditioning Research 25(5):p 1279-1284, May 2011.
- Metcalfe, R. S., Babraj, J. A., Fawkner, S. G., & Vollaard, N. B. J. (2012). Towards the minimal amount of exercise for improving metabolic health: beneficial effects of reduced-exertion high-intensity interval training. European Journal of Applied Physiology, 112(7), 2767-2775.
- Blue MNM, Smith-Ryan AE, Trexler ET, Hirsch KR. The effects of high intensity interval training on muscle size and quality in overweight and obese adults. J Sci Med Sport. 2018 Feb;21(2):207-212.
- D’Amuri A, Sanz JM, Capatti E, Di Vece F, Vaccari F, Lazzer S, Zuliani G, Dalla Nora E, Passaro A. Effectiveness of high-intensity interval training for weight loss in adults with obesity: a randomised controlled non-inferiority trial. BMJ Open Sport Exerc Med. 2021 Jul 20;7(3):e001021.
- Anderson J, Pudwell J, McAuslan C, Barr L, Kehoe J, Davies GA. Acute fetal response to high-intensity interval training in the second and third trimesters of pregnancy. Appl Physiol Nutr Metab. 2021 Dec;46(12):1552-1558.
- Wood, Kimberly M.; Olive, Brittany; LaValle, Kaylyn; Thompson, Heather; Greer, Kevin; Astorino, Todd A.. Dissimilar Physiological and Perceptual Responses Between Sprint Interval Training and High-Intensity Interval Training. Journal of Strength and Conditioning Research 30(1):p 244-250, January 2016.
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