Putting an End to the LSD vs. HIIT Debate

Over the last several years, there has been a growing trend in MMA conditioning circles to abandon any and all longer/slower forms of training in favor of higher intensity intervals. Experts often point to various research, supposedly showing the benefits of this higher intensity work, as proof that fighters don’t need to do any of the traditional style roadwork to get in top condition.

Fighting is an explosive sport, they argue, so running or training at a fairly slow pace won’t help you prepare for the high intensity energy system demands of MMA. Many even go so far as to say that this type of work will make you less explosive and weaker and so it should be avoided at all costs!

But is this really the case? Is high intensity interval training really the answer to everyone’s conditioning program like it’s been made out to be?

In this article, I’m going to make the case that while high intensity interval training is no doubt an effective conditioning tool and certainly should have its place in a fighter’s training program, the negative effects of longer slower distance training have been greatly overstated and it too should have a role in your conditioning program.

To begin with, it’s important to note that longer slower distance training (LSD) has been around in the conditioning programs of most combat sports almost since they began in one form or another. In boxing and wrestling, this form of training is typically known as roadwork. Rocky Balboa certainly wasn’t doing interval sprints down the streets of Philadelphia, he was jogging.

It’s safe to say that the vast majority of the best conditioned boxers throughout history have used roadwork in their training. It should also be pointed out that although everyone in the US seems to be jumping on the High Intensity Interval Training (HIIT) bandwagon lately, most MMA fighters from the rest of the world still use LSD in their training programs. There is more than one video online of the great Fedor doing roadwork in his native Russia, and it certainly hasn’t seemed to hurt his explosiveness or his conditioning.

I’ve also used LSD over the years with many top fighters such as Rich Franklin, Hayato Sakurai, Chris Leben, Matt Brown, Spencer Fisher, etc. and none of them seem have any problem with their power or knocking people out. But what about all the research showing how much more effective HIIT is? Critics of LSD like to point to research showing HIIT improved various measures of both aerobic and anaerobic fitness more effectively than lower intensity methods.

The research of I. Tabata out of Japan, in particular, has been referenced probably more than any other in this regard and has led to the Tabata interval craze that can be seen across the internet. The problem with this is that much of the research comparing LSD to HIIT has been extrapolated far beyond its limitations and applied completely out of context. The original Tabata research, for example, used just 14 subjects and they were all in relatively untrained and in poor shape with average VO2 max in the upper 40s and low 50s!

The results you see in relatively untrained subjects is often far different than what you see in experienced athletes. Second, all of the training in the study was done only on a bike, which is low impact and low resistance. Despite this, people are now applying the research protocol to all sorts of training, ranging from strength training to sprints to MMA specific exercises, without realizing how much more demanding on the nervous system and joints this really is.

Tabata had his subjects training 5 days per week, and also included one 30 minute session of LSD on one of these days (which is something never mentioned). Trying to recreate this training frequency with more demanding exercises than bicycling and 3-5 MMA training sessions a week thrown in the mix is a recipe for overtraining and joint pain. Finally, Tabata also used VO2 max and a test of anaerobic capacity to compare the results of LSD compared to HIIT.

Because of this, it should be no surprise whatsoever so that the higher intensity methods produced better results. Both VO2 max and anaerobic capacity are tests done at very high heart rates and very high intensities and so of course training done at higher intensities will be more effective when using these tests. The results would likely have been very different if Tabata had used other measures of aerobic fitness performed at lower intensities. This is the equivalent of testing 1RM max strength and then having one group use heavy sets of 1-5 reps and another group using sets of 10-12 reps.

Obviously, the group that did the heavier sets closer to what was being tested would improve their 1RM max more than the other group, but that doesn’t mean there is no reason to every do more than 5 reps in training. But why is LSD important? Can’t you get better results in far less time with HIIT? Despite what you’ve probably read, there are in fact benefits to LSD that you simply can’t get from higher intensity methods.

First, there are specific adaptations to the heart itself that are different between lower and higher intensity methods. Lower intensity methods done for longer periods of time, such as LSD type training, produces an enlargement of the left ventricle of the heart. This makes it possible for the heart to pump out more blood with each beat and thus it doesn’t have to work as hard to deliver blood and oxygen to the working muscles. This adaptation is known as eccentric cardiac hypertrophy.

Higher intensity methods, on the other hand, work to strengthen the muscle fibers of the heart and cause its walls to thicken as a result. This adaptation is referred to as concentric cardiac hypertrophy and it too helps the heart pump more blood and oxygen with each beat, but in a different way than the eccentric hypertrophy. Each of these adaptations works to improve your aerobic fitness, and both are important, but it’s important to understand that they differ in their effects on conditioning.

The lower intensity methods cause your heart to have to work less hard to deliver the same amount of blood and are thus well suited towards aerobic endurance. This also means your heart rate will stay lower as you exercise at a wide range of intensities and thus you can maintain them for longer. Higher intensity methods, by contrast, are better suited to helping your heart continue to pump more blood and oxygen at higher heart rates and thus enable you to maintain very high rates for longer before you become ultimately become fatigued and gas out.

This is obviously an advantage for MMA, but the lower you can keep your heart rate in the first place throughout a fight, the better your conditioning will be. LSD also has an advantage over HIIT when it comes to the muscles themselves. Longer slower training helps develop the capillary network that is responsible for delivering the oxygen supplied by the heart to the working muscles.

It takes a higher volume than you are likely to have with HIIT for this to happen, and without this development your muscles won’t be able to utilize as much oxygen and their endurance will suffer. MMA is a challenging mix of strength, power, speed, and endurance and requires careful and specific development of all three of your body’s energy systems.

Just as you must learn how to balance your striking skills with your wrestling and submission skills if you want to be a well rounded fighter, your conditioning and performance will be the best when the different systems in your body are finely tuned to work together to produce the energy you need in a fight. Along those lines, it’s important to realize that both LSD and HIIT help develop your energy systems in different ways.

There should not really be a debate about which one is better, they lead to different adaptations and each has their unique benefits. LSD is lower intensity and thus less impact on your joints and can be used more frequently. It helps your heart deliver more oxygen and keeps your heart rates lower. HIIT on the other hand, helps develop your aerobic power and your ability to sustain higher heart rates for longer.

If you want to have the kind of conditioning that wins fights, you should be using both LSD and HIIT in your training programs. Contrary to what you’ve been told, LSD will not cause you to become weak and slow and many of the best boxers, wrestlers, and even MMA fighters have used it in their training programs. For LSD to be effective and result in increased conditioning, I recommend doing 60-90 minute sessions using a variety of exercises.

You don’t have to just go running either, you can do everything from sled dragging to medicine ball exercises, jump rope, shadow boxing, flow drill submissions, etc. and simply do each one for 10-15 minutes at a time. You should also strive to keep your heart rate in the 130-150 range during this time for best results. HIIT can take a variety of different forms and the exact work: rest ratio and total volume of work should depend on your level of experience, work capacity, and specific training goals.

For beginners, 1-2 sessions per week of higher intensity training is usually a good place to begin. As your work capacity increases, you can then begin to increase the volume of HIIT training and user longer work with shorter rest intervals, depending on your conditioning needs. While research is invaluable to the progress of sport science and training as a whole, it can be easy to jump to conclusions and make training mistakes when looking at isolated pieces of the research puzzle.

In today’s fast paced society where time is short, everyone is looking for ways to get there quicker, or with less work. It would be nice if you only had to do 4 minutes of high intensity training a day to see maximum results and improve your conditioning, but the reality is that it takes much more than that. A carefully planned and well thought out training program that uses both LSD and HIIT in the right combination at the right times is the real key to developing ultimate MMA conditioning. LSD has been around for centuries because it does work and it does serve a specific and important purpose.

If you really want to improve your MMA conditioning, forget about the debate and make sure your training program includes both LSD and HIIT and I guarantee you’ll see the results.


  1. Joel, I would also add that many of us out there don’t have either the possibility or the knowledge to coordinate skill training with conditioning. I believe those who are forced to do lots of heavy sparring or demanding drills should avoid piling on more high intensity training when doing conditioning. For these people LSD can be much more beneficial than HIIT.

  2. Joel, this is a great read because I’ve always felt the need to implement both HIIT and steady state and I like how you describe how each training style affects the heart/CV system differently. Being able to deliver power over a greater time range (HIIT conditioning) is great but so is improved stroke volume/capillary density/mitochondrial density for better oxygen efficiency and lower blood pressure. Balance is best and too much of any training style without variation can have negative results.

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