The 3 Pillars of Health: Fitness, Food, Sleep

HIIT vs Cardio – Which is Better?


When it comes to things like exercise and diet, many people have strong opinions and like to champion their current favorites.

Let’s try to be even handed.

Let’s look at the pros and cons of HIIT vs cardio and see if one is clearly better than the other.

Defining Terms

I often find in debates (arguments) that the participants don’t have a clear idea of how each person understands the topic being discussed.

So, let’s start by defining our terms.

LISS Cardio means low intensity steady state cardio. LISS means that you train for a long period and your heart rate never exceeds 75% of its maximum.

HIIT means high intensity interval training. An HIIT workout alternates short bursts of intense activity with rest and recovery intervals. The intense intervals may have your heart rate as high as 85 – 90% of its maximum.

HIIT Pros and Cons

An HIIT workout can give you the following benefits:

  • increases your metabolism
  • afterburn effect – your body continues to use energy during the recovery time after your workout
  • you burn fat
  • you increase your muscle mass
  • workouts can be short

As they say, there is no free lunch. An HIIT workout has these cons:

  • workouts should only be done 2 – 3 times a week
  • may not be suitable for everyone
  • may be dangerous if you don’t exercise within your current fitness level

LISS Cardio Pros and Cons

Jogging is LISS cardio

Jogging is LISS cardio

An LISS Cardio workout can give you these benefits:

  • May be effective for fat loss (more on this later)
  • less stressful than an HIIT workout
  • your body works at a steady pace

On the other hand, LISS has these drawbacks:

  • long workouts
  • very little afterburn effect
  • may cause loss of muscle mass
  • your body can adjust to the training

The last point is one of the more interesting drawbacks of LISS.

Your body is an amazing mechanism with built-in systems to minimize stress.

One thing that can happen is that your body will adjust to a steady rhythm (think jogging) and learn how to do it more efficiently.

In many ways, that’s a good thing.

However, that increase in efficiency means that your body will burn fewer calories and you’ll lose less fat during your LISS workout.

HIIT vs Cardio

John Meadows, a personal trainer, recently published an article about HIIT training with the provocative title “Regular Cardio Makes You Fat.”

Disclaimer: John is writing for bodybuilders, that is men and women who are interested in having a certain muscular look during competitions. However, it seems that his major claims are applicable to everyone who works out.

His article has four take away points that you should know:

walking sign

Walking – Cardio to lose fat and keep muscle

  1. When combining cardio and dieting, do the minimum amount necessary for fat loss
  2. Walking is the most effective cardio workout for maintaining muscle mass
  3. If you are doing cardio to lose fat, then do it either slow and easy such as walking or do HIIT fast and furious. To do a medium [LISS] cardio workout can make you fat.
  4. HIIT should be considered muscle building cardio, not calorie burning cardio

Point #3 is saying that LISS can make you fat.

John explains why regular LISS cardio can make you fat:

If you’re dieting … but your cardio goes up, what’s the primary stimulus your body is going to need to adapt to? The cardio. Now how does one become more efficient at slow, aerobic cardio? By decreasing overall energy output, which means burning fewer calories to do the same activity.

So how do we [your body] increase energetic/caloric output? We get rid of the most metabolically expensive tissue we have that’s taking up those calories, which means our muscle.

In other words, your body adjusts to the current circumstances. If the muscles don’t seem to be needed and in fact may be hurting performance, then your body will consider the muscles to be “extra” weight that can be discarded.

HIIT vs LISS Cardio

The evidence is mounting that steady-state cardio, LISS Cardio, is not a good way to workout out.

This is especially true for a workout that does not bring your heart rate up to about 85% of your maximum heart rate.

According to John Meadows, you are better off doing cardio at a very low level such as walking or at a high level such as HIIT.


Photo Credit: Flickr – acidpix jogger
Photo Credit: Flickr – Peter Blanchard walk sign