Circuit Training vs. HIIT For Fitness and Fat Loss

According to research published on PubMed, lack of time is one of the most common barriers to regular exercise, affecting as many as 50% of those questioned (1). My experience as a 30-year veteran personal trainer supports this finding.

In fact, if I had a dollar for every time I heard this excuse, I’d have retired long ago!

That said, I also recognize that a lack of time really can make it hard to exercise regularly. After all, time is a valuable commodity, and you can’t get it back once it’s gone. Modern life places a lot of demands on our time, and when it’s running short, our workouts are often the first casualty.

That’s why I’m always looking for ways to make workouts more time-efficient. Ways to do this include using supersets, focusing on compound exercises, and exercising at home.

Two other time-saving methods I frequently use are circuit training and HIIT. While different, both deliver outstanding results in less time than most conventional workouts.  

But which is best – circuit training or HIIT? 

The main difference is that HIIT demands maximum effort during short bursts, while workout duration and rest periods in HIIT can vary more than in circuit training. Circuit training offers great flexibility and customization.

In this article, I compare and contrast circuit training vs. HIIT so you can choose the one that’s best for you.

Circuit Training vs. HIIT

Both circuit training and HIIT offer excellent cardiovascular benefits and involve alternating periods of exercise and rest.

Here’s how they differ:

• HIIT (High-Intensity Interval Training): Features short bursts of maximum effort followed by brief rest periods. HIIT is designed to dramatically improve cardiovascular fitness.
• Circuit Training: Involves a series of exercises performed at a moderate intensity with minimal rest. Circuit training improves both strength and cardiovascular health while offering great flexibility for various fitness levels.

Key differences:

• Intensity: HIIT prioritizes short periods of all-out effort, while circuit training focuses on sustained moderate intensity.
• Focus: HIIT is primarily a cardiovascular workout, while circuit training provides a well-rounded mix of strength and cardio benefits.
• Adaptability: Circuit training can be easily tailored to individual fitness goals and abilities.

Circuit Training: Definition, Benefits, and Example Workout

One of my first fitness industry jobs was teaching circuit training at a local sports and recreation center. However, while that was a long time ago (nearly 40 years!), circuit training is considerably older than that.

In fact, it was popularized by R.E. Morgan and G.T. Anderson at the University of Leeds, England, in the 1950s (2). That said, it’s probably been around even longer, with some experts suggesting it was practiced in ancient Greece and Rome.

Regardless of its origins, circuit training is a popular time-efficient workout. The fact that people are still doing circuit training after all these years is a testament to its effectiveness.

What is Circuit Training?

Circuit training is a workout where you perform several exercises back to back. In a traditional circuit training class, the exercises are called stations. There can be as few as six or 12 or more stations in a circuit workout, and a circuit can involve any type of exercise equipment or none at all, i.e., bodyweight exercises.

Most circuit workouts involve doing exercises for all major muscle groups. However, you can also use this method to overload a specific area of your body, e.g., upper body, core, or lower body circuits. Push-up circuits were especially popular when I was serving in the British Royal Marines.

Stations are typically done for a set time, e.g., 45 seconds, or for a predetermined number of reps. Some circuit workouts allow a short transition time between stations. In contrast, others require you to move immediately from one exercise to the next.

All these variables can be adjusted to change the intensity of the workout, making circuit training versatile and accessible for all fitness levels.

Related: What is Circuit Training? The Ultimate Guide to Get Lean

Circuit Training Benefits

So, what’s so great about circuit training? Consider these research-backed benefits (3):

Time-Efficient – conventional strength training invariably involves more time resting than exercising. For example, your set might take 20-30 seconds to complete, but then you spend 90 seconds recovering. The back-to-back format of circuit training means less time spent resting, so your workout won’t take as long.

Builds all-around fitness – circuit training involves doing multiple strength exercises back-to-back. This will develop muscular and cardiovascular fitness simultaneously. Consequently, there is no need to do separate cardio and strength workouts.

Great for weight and fat loss – circuit training burns more kilocalories than conventional strength training. Combined with an appropriate diet, circuit training can help you get lean and drop those unwanted pounds. Of course, the actual number of kilocalories burned will depend on the intensity and duration of your workout.

Related: How Many Kilocalories Do You Burn Doing Circuit Training?

Easy to modify – there is no single way to do circuit training. In fact, you can vary this training method to make it as easy or intense as needed. Modifiable characteristics include:

• Exercise difficulty
• Number of reps/duration per station
• Load
• Rest between stations
• Rest between rounds
• Number of rounds

You can even adjust the difficulty round by round. For example, you might decrease station duration for subsequent laps, such as 60 seconds per station for the first lap, 45 seconds for the second, and 30 seconds for the last lap.

Varied and enjoyable – if you hate doing the same workout over and over, you’ll probably enjoy the variability of circuit training. In fact, there is no need to do the same circuit program twice if you don’t want to.

Example Circuit Training Workout

Are you interested in trying circuit training for yourself? I don’t blame you – it’s an awesome workout! Here is a straightforward circuit training program you can do at home or anywhere you have space to move. All you need is a resistance band, an exercise mat, and a jump rope.

Do each exercise for 45 seconds, moving quickly from one to the next. Rest for 1-2 minutes between rounds, completing 2-4 rounds in total.

1. Alternating lunge
2. Push-ups
3. Air squat
4. Resistance band bent-over row
5. Plank
6. Jumping jack
7. Bench dips
8. Resistance band Romanian deadlift
9. Resistance band overhead press
10. Dead bug
11. Alternating step-up
12. Jump rope

Feel free to adjust the station durations and rest periods to match your abilities and experience.

HIIT: Definition, Benefits, and Example Workout

Cardio is a vital form of exercise that everyone should do. As well as developing your heart and lung fitness, it’s also good for your health. Regular cardio can help ward off cardiorespiratory illness and even contribute to longevity (4).

Unfortunately, conventional low-intensity steady-state cardio (LISS) can be time-consuming, and some people find it boring. HIIT workouts are much shorter, which is part of their appeal.

What is HIIT?

HIIT is short for High Intensity Interval Training. There are numerous interpretations of HIIT. Still, the most accepted variation involves short but intense bursts of anaerobic cardio alternated with brief rests.

The work-to-rest intervals depend on your fitness and the type of workout you prefer. For example, you might sprint for 20 seconds and walk for two minutes or adopt a 30-second on/30-second off ratio. As such, there is no single way to do HIIT.

While some forms of HIIT use strength training exercises, this is actually a form of High-Intensity Interval Circuit Training. HIICT combines both of the methods discussed in this guide.

Therefore, for the sake of simplicity, in this article HIIT means cardio exercises, e.g., rowing, air-bike, treadmill, outdoor running, jump rope, etc.

HIIT Benefits

Should HIIT be your go-to cardio workout? Consider these benefits and then decide:

Burn more kilocalories – while the number of kilocalories burned during HIIT depends on workout intensity and duration, studies suggest you’ll burn 20-30% more energy during HIIT compared to other types of exercise (5).   

Lose weight faster – HIIT may lead to faster weight loss than other forms of exercise. Studies also suggest that HIIT is effective in targeting abdominal fat, which is a leading cause of type 2 diabetes and heart disease (6).

Elevated post-exercise energy expenditure – HIIT triggers a greater EPOC of afterburn effect than conventional cardio (7). This is another reason that HIIT is so effective for fat-burning and weight loss.  

Increased cardiovascular fitness – HIIT is an anaerobic (without oxygen) workout, so it should be no surprise that it enhances anaerobic fitness. However, studies indicate that HIIT also has a positive influence on aerobic fitness (8).

Shorter workouts – as the old fitness adage says, you can train long, or you can train hard, but you can’t do both. HIIT workouts are much shorter than regular cardio and can be as short as 5-10 minutes while still being effective. 20-30 minutes of HIIT is as effective as a workout lasting twice as long.

Infinitely variable – there are lots of ways to modify an HIIT workout. The main variables you can adjust are:

• Exercise modality, e.g., bike, treadmill, elliptical, or rower
• Intensity of effort
• Length of work intervals
• Length of rest intervals
• Number of repeats

Manipulating these variables means you can create the perfect HIIT workouts for your experience, needs, and goals, and cardio need never be boring.

Example HIIT Workout

Would you like to incorporate HIIT into your workouts? Here is a sample workout to try. Adjust the work-to-rest ratio and number of repeats to suit your current fitness level. You can do this workout using any type of cardio, from indoor cycling to outdoor running.

• 5-minute easy warm-up
• 30 seconds sprint
• 90 seconds recovery
• Repeat for ten sets/20 minutes
• 5-minute easy cool-down

Circuit Training vs. HIIT: FAQs

Do you have a question about circuit training vs. HIIT? No problem! I’ve got the answers. But if you want more information, please drop me a line in the comments section below, and I’ll get back to you ASAP.

1. Is circuit training or HIIT best for all-around fitness?

While both workouts will make you fitter, HIIT mainly enhances cardiovascular fitness. In contrast, circuit training develops cardiovascular and muscular fitness, delivering more bang for your buck.

Personally, I like to combine HIIT with strength training in my weekly workout programs. However, if I want to enhance all-around fitness with fewer workouts, circuit training is arguably the best choice.

2. Which workout is more time-efficient – circuit training or HIIT?

While both workouts are short and intense, HIIT workouts are generally shorter than most circuits. One type of HIIT – Tabatas – lasts just four minutes. So, while circuit training makes good use of your time, HIIT workouts are generally shorter and more time-efficient.

3. Is circuit training or HIIT best for beginners?

Both circuit training and HIIT can work for beginners. That’s because you can modify them to accommodate a lower fitness level.

That said, even with those modifications, most beginners should start by doing a few months of basic cardio and strength training to build a foundation of fitness. Training too hard too soon can put some people off exercise.

4. Which is best for weight loss and fat burning – circuit training or interval training?

While HIIT probably burns slightly more kilocalories per minute than circuit training, most circuit workouts are a little longer. As such, the energy-burning effects of these workouts are very similar. Both have also been shown to be effective for weight management.

So, if you want to burn the most kilocalories in the least amount of time, HIIT is probably the way to go. However, performed consistently, both of these workouts can help you reach your goal weight or body composition.

That said, to lose weight with either workout, you’ll also need to adjust your diet and create an energy deficit. Neither workout will do much if you chronically overeat.

5. I only have time for one type of workout, so which should I do?

Both workouts can help you get in great shape. However, HIIT is more of a cardio workout, while circuit training works your cardiovascular and muscular systems. As such, circuit training is arguably the best choice if you only have time for one type of workout.

Conclusion

Circuit and high-intensity interval training are popular for a reason – they work! Both provide a time-efficient workout that’ll improve your fitness and burn fat.

However, while HIIT is predominately a cardiovascular workout, circuit training affects your muscular and cardiovascular systems. As such, circuits provide more bang for your training buck than HIIT.

That said, if you already lift weights or do some other form of strength training, adding HIIT to your program will be more than enough to develop a high level of all-around fitness. Doing weights and circuits will probably be overkill for most people.

References:

1. Hoare E, Stavreski B, Jennings GL, Kingwell BA. Exploring Motivation and Barriers to Physical Activity among Active and Inactive Australian Adults. Sports (Basel). 2017 Jun 28;5(3):47. doi: 10.3390/sports5030047. PMID: 29910407; PMCID: PMC5968958.
2. University of New Mexico: New Insights into Circuit Training, Len Kravitz, Ph.D.
3. Muñoz-Martínez FA, Rubio-Arias JÁ, Ramos-Campo DJ, Alcaraz PE. Effectiveness of Resistance Circuit-Based Training for Maximum Oxygen Uptake and Upper-Body One-Repetition Maximum Improvements: A Systematic Review and Meta-Analysis. Sports Med. 2017 Dec;47(12):2553-2568. doi: 10.1007/s40279-017-0773-4. PMID: 28822112.
4. O’Keefe EL, Torres-Acosta N, O’Keefe JH, Lavie CJ. Training for Longevity: The Reverse J-Curve for Exercise. Mo Med. 2020 Jul-Aug;117(4):355-361. PMID: 32848273; PMCID: PMC7431070.
5. Falcone PH, Tai CY, Carson LR, Joy JM, Mosman MM, McCann TR, Crona KP, Kim MP, Moon JR. Caloric expenditure of aerobic, resistance, or combined high-intensity interval training using a hydraulic resistance system in healthy men. J Strength Cond Res. 2015 Mar;29(3):779-85. doi: 10.1519/JSC.0000000000000661. PMID: 25162652.
6. Heydari M, Freund J, Boutcher SH. The effect of high-intensity intermittent exercise on body composition of overweight young males. J Obes. 2012;2012:480467. doi: 10.1155/2012/480467. Epub 2012 Jun 6. PMID: 22720138; PMCID: PMC3375095.
7. Wingfield HL, Smith-Ryan AE, Melvin MN, Roelofs EJ, Trexler ET, Hackney AC, Weaver MA, Ryan ED. The acute effect of exercise modality and nutrition manipulations on post-exercise resting energy expenditure and respiratory exchange ratio in women: a randomized trial. Sports Med Open. 2015 Dec;1(1):11. doi: 10.1186/s40798-015-0010-3. Epub 2015 Jun 5. PMID: 27747847.
8. Foster C, Farland CV, Guidotti F, Harbin M, Roberts B, Schuette J, Tuuri A, Doberstein ST, Porcari JP. The Effects of High-Intensity Interval Training vs. Steady State Training on Aerobic and Anaerobic Capacity. J Sports Sci Med. 2015 Nov 24;14(4):747-55. PMID: 26664271; PMCID: PMC4657417.

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