LISS vs HIIT: Which Approach Is Better?

Oct 2, 2020 - 7 min read
What to chose between HIIT and LISS

Cardio: the mythical beast that roams the lands of fitness. It is said to appear in many forms, with no general consensus as to what it looks like. Some claim it possesses incredible speed with which it bursts through the lands, taking stops in between sprints. Others claim it to be a slow creature that will not stop moving, moving endlessly at a steady pace.

Legends have spread the lands about its power to sculpt aesthetically pleasing bodies, improve cardiovascular health and aid in improving your overall health. Like any legend, effects are often exaggerated or misunderstood, with details being twisted due to poor memory or misinterpretation.

A lot of the stories are spread by the general media and TV ads, that often spread hype instead of facts. Today, we will go where few dare to venture and take a closer look at the beast, rather than passing along a twisted legend.

Like I mentioned in my previous article,  cardio is not essential for fat loss or weight reduction . It could be a useful tool in some cases, but that is exactly what it is: another tool in the toolbox. Like any other quality tool, knowing when and how to implement it is key.

People often tend to forget that when dieting (and thus being in a caloric deficit), their recovery is lowered and limited by their diet. A calorie deficit is a recovery deficit, so avoid deficit spending as much as possible.

Now the question I get asked a lot is which specific form of cardio I would recommend. This might seem like a really simple question to answer, but it is most definitely not. How so? Well, let us take a look at the two main types of cardio: HIIT and LISS.

HIIT: High-Intensity Interval Training

HIIT has gained a lot of followers over the last few years, with it eventually turning into a massive hype. The concept spawned multiple extremely popular programs like ‘Insanity’ for instance.

The idea behind HIIT is performing as much work as possible, within the shortest amount of time. Think 30 seconds of all-out sprints, followed by 1 minute of slow jogging/walking, followed by 30 seconds of all-out sprints, etc. The reduced total work time compared to regular endurance training is the reason that a lot of people prefer HIIT to ‘regular’ cardio.

Popular forms of HIIT include the regular ‘sprinting protocols’ (this includes sprints of a bike, or on an elliptical for instance), but also things like Tabata and Barbell Complexes.

In terms of effect, training at a maximum intensity would place more emphasis on the anaerobic system and thus type II muscle fiber utilization (which is similar to heavy strength training). In this case the emphasis shifts from endurance-based to maximum power-output.

In the end, continuing to increase the intensity and the rest periods of your cardio, will amount to you just doing (inferior)strength training. So if you are already performing strength training and spending time doing really ‘hardcore’ HIIT, you are just adding poor strength training on top of your regular strength training.

If that is your thing, because you love your HIIT: go ahead and be sure to enjoy it. If not, you may want to reconsider your workout planning.

LISS: Low-Intensity Steady State

On the other side of the spectrum, we have LISS cardio. This type of cardio places more emphasis on the aerobic system (meaning it is more ‘endurance based’) and requires a longer duration of time spent actually moving.

The most important thing when thinking LISS, is actually making sure it is low in intensity at a steady state. This might sound extremely obvious, but most people try to overdo it, turning their LISS into poor HIIT. When thinking about LISS cardio, think walks, swimming and cycling for instance.

Besides being better for burning some extra calories by just moving around, without impairing any of the adaptations from strength training (thus decreasing your recovery), LISS can be implemented pretty easily. If you go for a long walk with your dog, you are basically performing LISS cardio. Need to get something from the store? Hop on your bike and burn some extra calories.

So next time people ask you why you are taking your bike for a spin, instead of just getting into your car: tell them you are performing LISS cardio and smile (or just question the fact that most people in our modern society have become so lazy and sedentary that it is suddenly odd to walk or cycle somewhere, instead of just driving your car and spending time swearing at other annoyed folks in traffic, turning a 10 minute walk into half an hour of stress).

Combining strength training and cardio?

So now that we have established what the two types of cardio are, I want to take a look at combining cardio and strength training to reach your goals. We know cardio is absolutely not necessary for fat loss (if you missed my last article, you can read it here). Now the true question is: can you easily combine cardio and strength training, without them interfering with each other?

First and foremost, I want you to understand that strength and endurance training are two different things. We call this the interference effect. Your body cannot excel at both at the same time, since these are mutually exclusive physiological adaptations. So what happens when you try to improve both?

Simply put, your body finds a compromise: endurance and strength will both improve slightly. If you are serious about gaining more muscle mass, or getting really strong, you will need to keep this in mind. Cardio could in fact, due to the interference effect, increase the risks of muscle loss. Unfortunately, we cannot all be Bruce Wayne or Clark Kent and excel at everything.

Avoiding the interference effect requires you to perform your cardio in one of two ways: stimulate your body in a way that is similar to strength training (which would be HIIT), or stimulate it in a way that will not require much adaptation at all (this would be where LISS comes in).

Truth be told, the interference effect is best avoided by trying to avoid it all together. So LISS would be your best option. Go for a walk, cycle around town for a bit, or just walk your dog. Just move and enjoy it. As a woman, LISS is usually the superior option, since women do better on LISS than men. The reason being that the female physiology is well adapted to endurance and fat burning.

In conclusion: if you are serious about improving your physique, gaining muscle and growing stronger: cardio is not a desired method of fat loss, but rather a necessary evil at times. For the average gym goer that is not focused on maximizing muscle mass and strength, cardio and strength training can definitely be combined. Just take a good look at WODs workouts for example, try telling them that they cannot do both. Seriously, I dare you. And please film it and put the response video up on YouTube.

What is better HIIT or LISS?

  • For fat loss/weight reduction: diet should be the primary tool in your quest for that body you desire. If you do it right, you will not need any form of cardio at all.
  • Whatever form of cardio you do, try to keep it low impact to save your knees. Cycle, row, swim, hike, etc. Ironically, a lot of people assume running/jogging is something they cannot possible do wrong. They seem to forget that it is actually pretty technically demanding. Hence why a lot of people get injured from running; they do not know how to do so properly.
  • HIIT is a good way to improve conditioning when it is required for your sport/job, or you want to mimic the effects of strength training.
  • If cardio is necessary (for instance when increasing your deficit/reducing your caloric intake would mean not getting enough essential nutrients): LISS would be the best option.
  • For women, LISS is superior to HIIT as they respond better to its effects than men.

And last but not least: make sure you enjoy what you are doing. If you really want to spend time doing cardio, even though it might not be optimal: be sure to enjoy every minute of it. Hate running? Then do not go running. Go hiking, go for a swim, do bodyweight circuits, do a barbell complex, etc. Enjoy the process, for whatever you decide to do (in fitness, but also in life in general): you cannot do it in the long run, if you don’t enjoy it.

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Melania Armento

Melania is a SEO specialist at Virtuagym, one of the leading innovators in the digital health and fitness industry. With 6+ years experience in marketing, she loves fitness, ranking keywords with high monthly search volume, as well as taking advantages of long summer days and warm weather.