Sprint Interval Training: Burn 40% More Fat Than HIIT in 60% Less Time

Posted on 26 March, 2024 by Nicholas Rizzo


From fitness gurus and gym trainers to that one colleague who never shuts up about Crossfit, all will tell you exactly what you need to do to lose weight. 

We all know the benefits of exercising - despite how convincing all these so-called experts may sound, weight loss comes down to two things: 1) What you consume, and 2) What you do. That’s it.

The most obvious thing people do when they want to lose weight is cardio. HIIT has been one of the top fitness trends year after year and is commonly touted as the best way to lose weight. Instead of following the guidance of the misinformed, I conducted research to find out the facts.

The investigation compared sprint interval training, high-intensity interval training (HIIT), and moderate-intensity continuous training (MICT). It consisted of a meta-analysis of over 70+ scientific studies to uncover the answers to these two questions:

  1. What type of cardio exercises is best at burning body fat?
  2. Which of these forms of cardio are the most time efficient?

Key Conclusion

The data shows that sprint interval training led to a 39.95% higher reduction in body fat percentage than HIIT. Additionally, SIT participants exercised for 60.84% less time than HIIT. 

All Findings

Sprint interval training (SIT) vs High-intensity interval training (HIIT)

  • SIT resulted in a 39.59% higher reduction in body fat percentage than HIIT.
  • SIT significantly outperformed HIIT in Body Fat Percentage (BF%) reduction while requiring 60.84% less time spent exercising than HIIT.
  • SIT participants spent 81.46% less time sprinting in comparison to time spent doing high-intensity intervals of HIIT.
  • On average, SIT conducted 10% fewer workouts per week and these workouts were 44% shorter in comparison to HIIT.
  • During these workouts, the SIT group did 4.68% fewer sprints than the HIIT participants did their high-intensity intervals.
  • These sprints were 85.64% shorter in duration than the high-intensity intervals of the HIIT group.

Sprint interval training vs Moderate-intensity continuous training (MICT)

  • SIT resulted in a 91.83% higher reduction in body fat percentage than MICT.
  • SIT significantly outperformed MICT in Body Fat Percentage (BF%) reduction while requiring 71.17% less time spent exercising.
  • SIT participants conducted 15.54% fewer workouts every week on average compared to MICT.
  • These workouts for SIT were 60.12% shorter than MICT workouts.

The investigation

Studies were found by using specific boolean search queries in PubMed. Specifically, we used keywords to find studies that compared either two of the three training modalities or all three. If the study did not compare one of these three modes of training against one another but did provide other forms of variations in the training, it was included. After analysing several hundred studies, many studies were eliminated leaving the meta-analysis with approximately 75 studies. From that, studies that assessed adiposity were used to create the data and conclusions you see within this article.

  • 75 Studies that compare either two of or all three of SIT, HIIT, and MICT.
  • From these studies, the protocols of each training mode were identified and documented.
  • The averages for each parameter of the protocols were calculated for their respective training mode.
  • The percentage difference in the averages of these metrics was then calculated between SIT vs HIIT, SIT vs MICT, and HIIT vs MICT to determine the difference in effectiveness and efficiency.

Three forms of cardio: How are they different?

All three cardio regimens, SIT, HIIT, and MICT differ in their duration and intensity. Although it is easy to understand the difference in duration by using universally understood measures of time, how do we assess the intensity?

To do this, researchers would use testing equipment to consistently track specific metrics that equal to a desired level of intensity. They would asses things like the percentage of maximum heart rate (HRmax) or percentage of maximal oxygen uptake (VO2max).

To simplify this, we will be classifying the level of intensity on a scale of 1-10 using the modified relative perceived exertion (RPE) scale. The chart below shows The Borg Scale of Perceived Exertion in comparison to a modified RPE scale that goes from 1-10. It shows how one’s breathing may be at what level, an estimated percentage of maximum heart rate (MHR), and what type of exercise is done at that level.


In future visualisations of the different protocols, the y-axis will be this modified RPE scale to demonstrate the level of intensity and the x-axis will be time, allowing you to easily see the difference between these protocols.

What is sprint interval training?

Sprint Interval Training is actually a sub-type of HIIT but differs drastically in a few ways. In SIT, the intervals of higher intensity training consists of all-out sprints where you are giving 100% of your effort. Because of this extreme intensity, the duration of these intervals is very short. The workout itself has to be much shorter simply because working at this level of intensity is difficult to sustain.

The rest intervals in SIT will generally be longer or equal to than that of a HIIT workout and usually have a much lower work-to-rest ratio.

A common example of a SIT protocol

  • 4-6 30-second sprints at an intensity of 10.
  • Rest for 2-4 minutes after each sprint.
  • Rest period consists of either fully resting (intensity of 0) or low-intensity active recovery such as walking (intensity of 1).
  • Repeat this workout 2-3 times per week.

Sprint interval training workout: the average protocol tested

Through the analysis, the studies analysed used a range of anywhere from a 1:9 work-to-rest ratio to 1:3 work-to-rest ratio. The combined average of all the tested sprint interval training protocols used in this meta-analysis was:

  • 8 sprints per workout (rounded up from 7.68)
  • 27.6 seconds sprinting duration
  • 2 minutes and 44 seconds of rest after each sprint

The intensity levels during SIT on the modified RPE scale were:

  • Average sprint interval intensity = 10
  • Average rest interval intensity = 1


When visualised, it is clear that Sprint Interval Training is less of an endurance exercise and more of a maximum effort challenge. Even if the workout lasts X minutes, you are actually only doing 2 minutes of actual demanding work. The other Y minutes of the workout are spent resting at an extremely low-intensity.

What is high-intensity interval training?

High Intensity Interval Training workouts generally last around 30-40 minutes although they can be a bit shorter. The “high-intensity intervals” are typically in the 2-4 minute range. Although that may be much longer in length than the sprints in SIT, the intensity of these intervals are lowered in order to compensate for the longer duration.

Typically, HIIT operates at a higher work-to-rest ratio than SIT.

A common example of a HIIT protocol:

  • 4-8 sets of 2-4 minute sprints at an intensity of 6-8
  • Rest for 1-3 minutes after each sprint
  • Rest period consists of active recovery at an intensity of 1-3
  • Repeat this workout 3-4 times per week

High-intensity interval training workout: the average protocol tested

Through the analysis, the studies used a range of anywhere from 1:2 work-to-rest ratios to 2:1 work-to-rest ratios. The intensity of the recovery intervals does tend to be slightly higher than that seen in Sprint Interval Training.

The combined average of all the tested high-intensity interval training protocols used in this meta-analysis was:

  • 8 sprints per workout (rounded down from 8.05)
  • 2 minutes and 24 seconds sprint duration
  • 2 minutes and 8.4 seconds rest duration

The intensity levels during HIIT on the modified RPE scale were:

  • Average sprint interval intensity = 7
  • Average rest interval intensity = 2


HIIT workouts are extremely challenging due to the long duration of the high-intensity intervals. Additionally, the rest intervals are at an intensity high enough to labour your breathing.

What is moderate-intensity continuous training?

Moderate Intensity Continuous Training is what most would consider the most traditional form of cardio. Going for a run or hopping on a bike and putting in a consistent effort for a longer duration of time is the goal of this training.

Because the duration of the workout is longer and there are no rest intervals, the overall intensity is also lower.

Generally, your breathing will become harder and deeper in MICT. It becomes a little bit more difficult to hold a conversation during this type of training, although you can still talk.

A common example of an MICT protocol:

  • Continuous training for 30-60 minutes at an intensity of 2 - 5

Moderate-intensity continuous training: the average protocol and intensity levels tested:

  • Average session duration = 40 minutes and 31.8 seconds
  • Average session intensity = 4


The traditional cardio we all know and love (or hate) is as simple and straightforward as possible. Exercise at a moderate intensity for a set period of time.

When we compare these three protocols together, it becomes abundantly clear just how drastic the differences are.


Sprint Interval Training, from my biased perspective, looks like the easiest form of exercise, even if it does require the highest level of intensity out of the three.

Results of the investigation

The objective of this investigation was to identify which form of cardio is the most effective at reducing body fat percentage and which one does it in the most time efficient manner.

The studies involved specific programmes that were classified as SIT, HIIT, or MICT. 

The exercise regimens consisted of varying amounts of workouts per week, workout durations, etc. but all lasted an average of 9.8 weeks long. 

Effectiveness was also measured with a single metric of body fat percentage.

Doing Sprint Interval Training reduced body fat percentage 40.70% more than High Intensity Interval Training and 91.83% more than Moderate Intensity Continuous Training


Each mode of exercise are effective at reducing body fat in their own right. However,  SIT is the leading performer with a 2.31% body fat reduction, HIIT with a 1.64% reduction, and MICT with 1.2% reduction.

In comparison though, it is clear that SIT is the most effective form of cardio to burn fat. Having outperformed both HIIT (by 40.70%) and MICT (by 91.83%).

HIIT was the second most effective as this population of participants lost 1.64% of body fat in comparison to MICT’s 1.2%. Meaning HIIT was 36.34% more effective than MICT.

What is the most efficient form of cardio?

It’s clear that SIT is the most effective form of cardio when it comes to reducing body fat.

But which is the most efficient?

The average study lasted approximately 9.8 weeks.

Within those 9.8 weeks, we assessed efficiency by analysing the following metrics:

  • Total time spent exercising
  • Total time spent sprinting which only applies to HIIT and SIT (sprinting = sprints of SIT and the high-intensity intervals of HIIT)
  • Average workout duration

SIT required 60.84% less overall time spent exercising than HIIT and 71.17% than MICT


Over the 9.8 weeks, the SIT groups conducted a total of 389.7 minutes of exercise on average. These participants spent 60.84% less time exercising in comparison to HIIT (995.17 minutes over 9.8 weeks) and 71.17% less than MICT (1351.62 minutes over 9.8 weeks). 

Making it clear that SIT is extremely time efficient as it required approximately only a third the time of HIIT to complete.

SIT workouts consisted of 81.46% less time sprinting than HIIT workouts


When comparing the amount of time spent doing sprints or cardio at the highest intensity within the protocol, the difference is drastic as well. Sprint Interval Training participants spent just over an hour sprinting where HIIT spent over 7 hours on average throughout the duration of these studies.

Overall, SIT spent 81.46% less time doing high-intensity work. The major difference being that the level of intensity was at its highest for SIT. This type of intensity training pushes what your body is physically capable of to its limits. Even though the amount of time is so much different, don’t mistake it for being easy.

SIT workouts were 44.75% shorter than HIIT workouts and 60.12% shorter than MICT


Although HIIT was shorter than the average MICT workout by about 11 minutes, it still was not as efficient as SIT. SIT workouts were 13.1 minutes shorter than HIIT and 24.37 minutes shorter than MICT.

This made SIT almost 50% more efficient on an individual workout basis in comparison to HIIT.

Why is SIT so effective and efficient?

This investigation has demonstrated that SIT outperforms other forms of cardio training when it comes to reducing body fat. Not only that but SIT also produces these results in almost half the time of HIIT.

But how is that even possible?

Your body is constantly communicating with itself through a wide variety of feedback loops trying to maintain a state of homeostasis. Think of homeostasis as your body’s internal “comfort zone”.

Remember Newton’s Third Law from your middle school science class? For every action, there is an equal and opposite reaction.

This applies directly to this comfort zone. As you push your body out of homeostasis through exercise, it has to react in an equal and opposite way in order to bring balance back to all interdependent systems within your body.

The greater the intensity, the more you are able to push your body out of homeostasis.

The benefits of increasing the intensity of your workout aren’t linear though. It can be better visualised as being exponential growth.


Where HIIT is operating at an intensity of "8" it is s

On the intensity scale, sprinting is a 10-out-of-10. This maximal intensity leads to pushing your body extremely far out of its' comfort zone. 

Kickstarting the biological processes 

By operating at this maximal intensity during SIT, you are producing the maximal response from your body which is what allows the duration of exercise to be so strikingly shorter than that of its counterparts.

How to implement SIT in your exercise routine?

When beginning Sprint Interval Training, you want to make sure you incorporate and apply it in a programme with progressive overload. This will help to ensure safety and allow you to train in a zone of maximum effectiveness as you progress.

The objective of programming is to go from a beginner in SIT, to being able to consistently workout 3 times a week where the protocol consists of 4 x 30-second sprints with 4 minutes of rest duration.


If you are a more advanced athlete with a great deal of experience in high-intensity exercise such as HIIT, you can simply start at Week 10. From there, as you see fit, increase the intensity by reducing the rest duration, increasing the sprint duration, or increasing the number of sprints per workout.

You should also make these increases in intervals of every 2-3 weeks and be sure to provide your body with the adequate rest that it needs. If you continue to show up to your workout still sore and struggling to give your maximum effort, then increase the number of rest days between workouts.

Great training shoes are a must for interval training

If you are one of the ones trying to lose that weight gained during quarantine, then you need to start with the proper footwear is always crucial. Some of the best training shoes can make a significant difference in your stability, comfort, and performance. It is important to match your shoe with the proper exercise as well. Weightlifting shoes are better suited for stationary exercises, like squatting. In comparison, the best CrossFit shoes will be significantly different and provide much more support for crosstraining purposes. 

For those who don't want to spend top dollar on the best workout shoes just for interval training, there are tonnes of cheap training shoes that are rated just as well as expensive ones.

Every year, there are tonnes of new training shoes coming out from big brands like Nike, PUMA, and Reebok. But don't forget to check out smaller shoe brands as well. Companies like Vibram FiveFingers, Topo Athletic, and Vivobarefoot may have a much smaller offering but don't mistake that for a lack of quality. 

Because of the intensity of SIT, it isn't suggested to do it every day. Instead, getting out for some vigorous walking is a great option. You can find the best walking shoes for you, whether they are shoes for all-day wear, travelling, or for work. There are even great shoes for diabetics and other foot conditions such as flat feet, overpronation, or even plantar fasciitis

Works Cited:

1) Little JP, Langley J, Lee M, Myette-Côté E, Jackson G, Durrer C, Gibala MJ, Jung ME. Sprint exercise snacks: a novel approach to increase aerobic fitness. Eur J Appl Physiol. 2019 Mar 7.doi: 10.1007/s00421-019-04110-z.

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70) Burgomaster KA, Howarth KR, Phillips SM, et al. Similar metabolic adaptations during exercise after low volume sprint interval and traditional endurance training in humans. J Physiol Lond. 2008;586(1):151–60. doi:10.1113/jphysiol.2007.142109.

71) MacPherson RE, Hazell TJ, Olver TD, et al. Run sprint interval training improves aerobic performance but not maximal cardiac output. Med Sci Sports Exerc. 2011;43(1):115–22. doi:10.1249/ MSS.0b013e3181e5eacd.

72) Rowan AE. Short duration high-intensity interval training improves aerobic conditioning of female college football players. Int J Exerc Sci. 2012;5(3):232–8.

73) Sandvei M, Jeppesen PB, Stoen L, et al. Sprint interval running increases insulin sensitivity in young healthy subjects. Arch Physiol Biochem. 2012;118(3):139–47. doi:10.3109/13813455. 2012.677454.

74) Laursen PB, Shing CM, Peake JM, et al. Interval training programme optimisation in highly trained endurance cyclists. Med Sci Sport Exerc. 2002;34(11):1801–7.

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Nicholas Rizzo
Nicholas Rizzo
Nick combines 10+ years of experience in the health and fitness industry and a background in the sciences in his role as the Fitness Research Director. During his competitive powerlifting years his PRs have him sitting in the top 2% of bench presses (395 lbs), top 3% of squats (485 lbs) and top 6% of deadlifts (515 lbs) for his weight and age. His work has been featured on Bodybuilding.com, LiveStrong, Healthline, WebMD, WashingtonPost, and many more. Along the way, collaborating with industry leaders like Michael Yessis, Mark Rippetoe, Carlo Buzzichelli, Dave Tate, Ray Williams, and Joel Seedman.