Complete Guide To Supramaximal Interval Training (S.M.I.T.)

Mike Wines
Written By: Mike Wines
February 24th, 2015
Updated: March 26th, 2021
Tags: Expert Guide
61.6K Reads
Complete Guide To Supramaximal Interval Training (S.M.I.T.)
Learn the difference between two highly-effective interval training methods, get answers to some FAQs, and set-up your own interval training program.
This Guide Teaches You:
  • A general overview of both types of training methods.
  • What the differences between HIIT and SMIT are.
  • Which is more important: intensity or duration.
  • The importance of work to rest ratio, and what it means in term of energy systems
  • Answers to the most frequently asked questions about HIIT and SMIT.
  • How to set up an upper/lower split workout program.
  • Important practical takeways when it comes to interval training.

HIIT/SMIT Overview

Have you ever walked into a commercial gym and wondered why some folks are plodding along on a treadmill or pounding away at a stationary bike like they’re on the last leg of the Tour de France? Well, if your goal is to get lean and build a solid physique, odds are that’s not going to get you there.

Training efficiency should always be a top priority, so it’s quite beneficial to utilize different HIIT (High Intensity Interval Training) protocols rather than spending hours on a treadmill. Interval training allows us to improve various cardiovascular markers and generate a greater work capacity in less time. 2 for the price of 1, now who doesn’t want that?!

But, what if I told you there was another method which might be even MORE beneficial than the holy grail of interval systems (HIIT)?

Enter supramaximal interval training (aka SMIT).

Athlete Training

The Battle of Bioenergetics - HIIT vs. SMIT

Walking or jogging? 1, 3, or 5 sets? Rice or potatoes? Whey or casein?

Seems like there’s always some debate raging within the fitness community; well, interval training is no different. What’s the difference in HIIT and SMIT? Is one better than another or can they both be used to produce exceptional results?


  • All out intensity.
  • Passive recovery is recommended.
  • Over 100% of VO2 max.
  • Lengthy rest periods in excess of 2-3 minutes.
  • Various modalities possible - some better than others.


  • Slightly lower in intensity.
  • Passive or active recovery depending upon length and intensity of interval.
  • 90-100% of VO2 max.
  • Shorter rest periods (0:45-1:30) due to decreased intensity.

I’m sure some of you are wondering, “What is a VO2 max and how can I go above 100 on a absolute percentage scale?” Well, it’s essentially the maximal amount of oxygen your body can take in and utilize during exhaustive exercise. Once you reach your VO2 max (100%), your body switches energy systems in order to produce enough energy to meet the demands of the situation.

Athlete Training

Now that we’ve nailed down some terminology and a general overview, lets look at what the research has to say.

A recent study in the European Journal of Sport Science sought to compare the training adaptations and benefits between HIIT and SMIT. The researchers took physically active males and females and split them into 3 groups who trained 3 times per week for 6 weeks:

  1. HIIT:
  • 100% of VO2 max
  • 4-6 intervals per session
  • 4 minutes of passive recovery
  1. SMIT:
  • 130% of VO2 max
  • 7-12 intervals per session
  • 150 seconds of passive recovery
  • 30 Minutes of continuous running @ 75% of VO2 max

So what happened after 6 weeks? Well, to quote the study directly: “improvements in 3000m time trial performance were greater following SMIT than continuous running, and improvements in 40 meter sprint and repeat sprint ability (RSA) performance were greater following SMIT than HIIT and continuous running” (Cicioni-Kolsky et al., 2013).

SMIT beat out both continuous running and HIIT for improving endurance, sprint, and repeat sprint performance in physically active individuals. The researchers also noted that there seemed to be a gender specific response to the training modality in the 3000m-time trial as females improved even more than males.

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Intensity vs. Duration - A Double Edged Sword

Ah, the ago old question, which is more important: intensity or duration? If you ask me, I’d say both.

When it comes to intervals, both must be taken into account in order to design the best program possible. As such, there’s one vitally important caveat that we must never forget: INTENSITY AND DURATION ARE INVERSELY PROPORTIONAL.

So in other words, you won’t be able to maintain 100% output for any sustainable length of time, no one can. As I mentioned in the discussion above, there are certain systems within your body, which can produce maximal power output, but only for a very limited amount of time.

Interval Training for Different Energy Systems
% of Maximum Anaerobic Pwr. Energy System Taxed Interval Time Work:Rest Ratio
90-100 Phosphogen 5-10s 1:12 to 1:20
75-90 Fast Glycosis 15-30s 1:3 to 1:5
30-75 Fast Glycosis and Oxidative 1-3min 1:3 to 1:4
20-35 Oxidative >3min 1:1 to 1:3
From Essentials of Strength Training and Conditioning, NSCA (2000)

How do we use this information in the context of SMIT? Well, if you refer to the chart above, you’ll see that intervals requiring 100% output only last for 5-10 seconds and require a 1:12 to 1:20 work to rest ratio.  That means if your sprint only last 5 seconds at maximal intensity, you should be resting a minimum of 60 seconds in order to allow complete repletion of your energy systems.

Work rest ratios determine which energy system is being utilized as well as the physiological adaptations that occur. If you’re neglecting rest periods and simply performing intervals “whenever you feel like it”, then you’re training is going to lack long term progression and ultimately results.

Athlete Training


Q: Can anyone do SMIT?

A: Due to the intensive nature of SMIT, I would recommend that only more advanced trainees utilize it. Begin with some HIIT (sleds pushes, jump rope, bike, battling ropes, etc.) and then work your way up to SMIT as your work capacity increases and your aerobic base improves.

Q: Since the research showed SMIT was ‘superior’ to HIIT and continuous running, then SMIT is my best option, right?

A: Wrong. Your body requires periods of lower and higher intensity training based upon external stressors, each individual’s recovery ability, and your current level of fitness. As I mentioned in the opening paragraph, the principle of S.A.I.D. applies to SMIT as well - your body will adapt to the stimulus over time and your training with lose effectiveness.  Also, utilizing only one style of training tends to get boring and monotonous, mix it up to keep yourself interested! Remember, consistency and sustainability are the keys to success.

Q: How many times per week can I perform SMIT?

A: This will depend upon the rest of your training schedule as well as your goals. But, for the general gym attendee who is lifting 3-4x/week, I would recommend 1 session of SMIT and 1 session of HIIT or LISS.

Q: How long should my intervals last?

A: Anywhere from 5-15 seconds - after this point, you will begin to lose maximal power output and it’d be best to begin your rest period.

Q: How many intervals should I perform per session?

A: 4-8 sprints is likely a good place for most folks to start. Always start on the lower end and work your way up. You didn’t squat 10 sets of 10 your first day in the gym (at least you shouldn’t have), approach your conditioning in the same manner.

Q: What is the best conditioning modality for this style of intervals (bike, rower, sprinting, treadmill, etc.)?

A: Ideally, I would recommend non-weight bearing options to begin with. Stick to the rower, bike (airdyne is the best choice), or VersaClimber. However, as you begin to advance in your training, seek to utilize other ground-based options such as hill sprints (note: I do not say FLAT sprints) or running stadiums. These options require each step to be higher than the pervious one and as such, they limit eccentric stress to your joints.

Q: I’ve been training for a while and enjoy sprinting (flat and hill) but I always seem to pull a hamstring, what should I do?

A: Always build up into each sprint. Due to the fact that many hamstring issues are due to explosive take offs (think: NFL’s 40 yd dash) and over striding, it’s best not to go from 0 to 100% in a few steps. Give yourself 10-15 yards to build up speed and then begin your sprint up the hill or linearly.

Q: How long should I rest?

A: Again, this will depend upon the length of your interval, your goals, and your fitness level. Begin with the higher end of the work to rest ratio (1:20) and seek to decrease towards the lower end (1:12) as you improve.

Q: If I choose to do SMIT, can I do HIIT or LISS with it?

A: As I mentioned above, I recommend including all 3 options due to their differing intensities and physiological adaptations.

Q: Why should I do LISS when I could just do SMIT and/or HIIT?

A: This question is another article in and of itself but to suffice it to say, constant levels of high intensity training WILL burn you out eventually. LISS is an excellent way to promote recovery, balance neurotransmitters (Dopamine, Serotonin, and Norepinephrine) within the brain, and enhance neural plasticity.

Q: I’m an athlete, should I perform this style of conditioning?

A: Like most other questions, this one depends as well. Conditioning for sports and conditioning to “stay in shape” require two entirely different programs. So to put it simply, yes, this style of conditioning is certainly an option for athletes. Is it necessary THE BEST option given their experience, age, and sport specific demands? Maybe not…

Q: Which is better: steak or eggs?

A: Trick question, the answer is both…Threw that last one in just to make sure you were still paying attention.

Athlete Training

SMIT: Upper/Lower Split

Most HIIT or SMIT protocols are very intensive in nature and as such, I recommend that folks program their lower body work a day before or after the session of intervals. Also, it’s important to remember that the interval work can be auto-regulated based upon your training sessions. If you hit an exceptionally hard leg session on Friday, then simply dial back your HIIT a bit on Saturday.

If you were going to set up your own program, here’s a template that could work exceptionally well.

A1: Deadlift Variation 3,2 3,8
A2: Overhead Medicine Ball Slam 5 4
B1: Glute-Ham Raise 4 6-10
B2: Split Squat 4 8-10E
C1: Hanging Alternating Leg Raises 3 6-8E
C2: Side Plank 3 4 (15sec./rep)
Incline Dumbbell Bench 4 4,6,8,10
Weighted Chinup (Suspinated or Hammer Grip) 3 5-7
A1: Paused Decline Push-Up 3 8-10
A2: Dumbbell Row 3 8-12E
B1: Overhead Tricep Extension 3 12-15
B2: Half-Kneeling Facepull 3 10-15
DAY 3 - SMIT Supramaximal Intervals
Select ONE modality from the list below:
  • Stationary Bike (Airdyne preferably)
  • Rower
  • VersaClimber
4x8, 5-15sec. rounds
Full Body Foam Roll 1 10mins.
Additional Soft Tissue Work 1 10mins.
Dynamic Warm-Up 1 10mins.
Front Squat 3 6-8
Snatch Grip Romanian Deadlift 3 8
A1: Single-Leg Leg Press 3 6-10E
A2: Leg Curl 3 12-15
B1: Dumbbell Hammer Curl 3 8-10E
B2: Front Plank 3 4 (20sec./rep)
Standing Overhead Press 4 6
Chest Supported Dumbbell Row 4 8-12
A1: Dips 4 10-12
A2: Wide-Grip Pulldown 4 10-12
Dumbbell Tricep Extension 3 8-12
A2: Eat
A3: Watch Football
HIIT High Intensity Intervals
Select ONE modality from the list below:
  • Battling Ropes
  • Incline Treadmill Sprints
  • Stationary Bike (Airdyne Preferably)
  • Jump Rope
  • Rower
  • Prowler/Sled
4-6, 15-30sec. rounds

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Practical Takeaways

  1. HIIT and SMIT are commonly mistaken as being the same by both trainer and trainee alike.
  2. Due to the intensive nature of SMIT, it cannot be used as your only conditioning modality. Incorporate both HIIT and LISS as well.
  3. SMIT intervals are higher in intensity, requiring shorter durations and lengthier recovery periods.
  4. Utilize non-weight bearing modalities when possible in order to save your joints in the long run.
  5. Structure your conditioning around your training, not the other way around.
  6. Utilize 4-8 intervals (5-15 seconds a piece). Keep your work to rest ratio at 1:20 initially and then slowly decrease towards 1:12 as your fitness improves.

Remember, there should always be reasoning behind your methodology; don’t just do conditioning to make yourself tired, train with a purpose.

Salazar Tennyson
Posted on: Sun, 04/15/2018 - 12:46

Well, by passive recovery do you mean sitting? Should you sit in rest periods in SMIT and walk/jog in HIIT?

Posted on: Mon, 06/15/2015 - 05:17

If SMIT is meant to have longer rest periods why then in your test did you have 150 seconds recovery for SMIT and 4 minutes recovery for HIIT?

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Posted on: Mon, 06/15/2015 - 09:00

Good question. If you look at the original research study, the HIIT participants were performing 4 minutes of work where as the SMIT group was performing 30 second intervals. Longer periods of work necessitate more recovery.

Posted on: Mon, 03/02/2015 - 14:56

Hi Mike,

Thanks for contributing this article. Currently, I incorporate 1-2 HIIT sessions per week for cardio. I also included an off day where I go to boxing for conditioning. Some of the drills we do in boxing sound very similar to SMIT.

For example, often I do 10 seconds of all out punches on the heavy bag for 10-15 seconds followed by a 45-60 second rest period. We usually go through this 5 times, maybe more if my trainer wants to torture me. Would you say boxing could count as a SMIT activity?

Thanks again for the contribution.

Posted on: Mon, 03/02/2015 - 20:04

Hey Steve,
Those rest periods may need to be extended just a bit in order to allow for complete repletion of that energy system (phosphagen). I'm not entirely sure what your current goals are or what your trainer is directly trying to accomplish with this method of training but see if you could suggest for a lengthier rest period to enhance the next subsequent bout of punches. I think you would find you're able to keep a higher intensity and enhance your recovery in between sets.

Boxing could definitely could for SMIT although it's important to keep in mind that it may be tougher to get your heartrate into 110% of your VO2 max b/c you're utilizing only upper body. Again, I've never tried that method personally or seen any studies on just upper vs. lower body modalities but I would imagine that it would be easier to reach your VO2 max quicker by incorporating the largest group of muscle mass possible. I think it's definitely possible, might just take a bit more work and concentration on the intensity.

Posted on: Tue, 02/24/2015 - 21:43

**NOTE: The HIIT session that's included after Day 7 should be implement after the upper body lift on Day 6. That was specified within the text but somewhat tough to conclude based upon the layout. Just wanted to clear that up!