Steady State Cardio vs. HIIT For Fat Loss

Fat loss is one of the most common fitness goals on the planet. When we consider it has relevance from both a health and an aesthetic perspective, it is very easy to understand why.

And when it comes to fat loss, cardio is a must -- but is one form better than the other?

What causes fat loss?

Although there are a number of unique social, environmental, and physical factors that can influence someone's ability to lose weight, it ultimately comes down to one thing -- expending more energy than you consume for an extended period of time [1].

Every single day you burn energy. This energy is used to perform tasks of daily living, fuel your exercise habits, and ensure that every single one of your cells is performing its specific role within your body.

This amount of energy is known as your “total daily energy expenditure,” and it describes the amount of energy you expend every single day (keep in mind that this “energy” is often measured in “calories”).

If you are looking to lose weight, you ultimately need to ensure that the calories you burn each day are greater than the calories you consume. This puts you in a “calorie deficit,” and forces your body to rely on its own energy sources to get through the day -- with the largest energy store in your body being fat. 

 As such, being in a calorie deficit results in fat loss, because your body is forced to burn fat for energy to support your daily functions.

Now, you can achieve a calorie deficit in one of two ways:

1. You can reduce the amount of energy you consume by changing your dietary habits, or:
2. You can increase the amount of energy you expend through exercise.

With this in mind, we are going to dive a little deeper into exercise and fat loss.

Why Cardio for Fat Loss?

While weight training is an amazing tool when it comes to changing how you look, it is not the most effective way to promote fat loss because it does not burn a huge amount of energy.

This makes sense when you consider that, during most weight training sessions, you perform more time resting between sets than you do exercising.

However, cardio offers a much more effective fat loss tool.

Because it involves a high degree of consistent effort, it also causes a consistent and sustained increase in energy expenditure. This makes it a more effective method to increase the “energy out” side of the equation we spoke about earlier [2].

Steady State Cardio and HIIT

When talking about cardio, it can really be broken down into two main types: Steady state cardio, or high intensity interval training (HIIT for short).

Steady state cardio typically involves cardio performed at a low-to-moderate intensity of effort (less than about 80% of your maximal heart rate), over a longer period of time (more than 30 minutes), and within a single bout.

 Conversely, HIIT is a type of cardio performed in multiple shorter bouts of high intensity activity (more than 80% of your maximal heart rate), interspersed with recovery periods that are either done at a much lower intensity, or in a state of complete rest.

As an example, going for a light 60 minute jog would be considered steady state cardio. On the other hand, a HIIT session might involve doing 30 seconds at near maximal effort, followed by 30s of complete rest, for a total of 30 minutes.

Steady State Cardio vs. HIIT For Fat Loss

Now for the crux of the article -- when it comes to fat loss, is one better than the other?

Fortunately for us, a recent meta-analysis (a study that combines the results of multiple studies) looked to answer this question. 

The authors of this meta-analysis combined the results of 54 individual studies comparing the effects of steady state cardio and HIIT on fat loss, and found that they both caused the exact same amount of fat loss [3] -- however, there are some considerations that should be mentioned.

The average weekly dosage of all steady state cardio in all the studies per week was ~120 minutes, whereas it was only ~30 minutes for the HIIT sessions.

So, what does this imply?

Well, HIIT training is performed at a much higher intensity than steady state exercise. As a result, it burns more energy per minute, which is why it might be considered a more “efficient” tool for fat loss.

What should you choose?

The good news is that both modes of cardio are effective, so you can make your decision entirely on personal preference.

If you can only sneak in two 20 minute cardio sessions per week, then HIIT is going to be your best bet. On the other hand, if you enjoy going for a big run on your non-gym days, then doing two 60 minute steady state sessions probably makes the most sense for you.

With this in mind, your best bet is to choose the type of exercise you enjoy the most, or most easily fits within your schedule -- because that is what you are more likely to commit to over the long term.

Final Point

Despite what you may have heard, both steady state and HIIT training are equally effective for fat loss -- which simply means that you should choose the one that suits your personal situation best!

References:

1. Strasser, B., A. Spreitzer, and P. Haber. "Fat loss depends on energy deficit only, independently of the method for weight loss." Annals of Nutrition and Metabolism 51.5 (2007): 428-432.
2. Grieve, George Lewis. "The effects of exercise mode and intensity on energy expenditure during and after exercise in resistance trained males." (2018).
3. Steele, James, et al. "Slow and steady, or hard and fast? A systematic review and meta-analysis of studies comparing body composition changes between interval training and moderate intensity continuous training." Sports 9.11 (2021): 155.

Personally, I have been performing high intensity interval training (HIIT) cardio consistently for well over 3 years now. Yet, even with many hundreds of sessions under my belt, every HIIT workout continues to be a learning experience for me. Within this article, I will break down the main components of an effective HIIT workout and explain some techniques to really step your HIIT workout to the next level!

Interval or High Intesity Interval Training (HIIT) presents a heap of fitness benefits which include better aerobic capacity and more calories burned.

New research demonstrates that a short cardio training session (high intensity interval training, or HIIT) is an efficient and effective alternative to long cardio sessions.

HIIT cardio will result in significant fat loss - far more significant than 60-70% max heart rate. Lower intensity exercise utilises fat as a primary energy fuel source during exercise, but the net adipose tissue (fat tissue) breakdown is far greater with HIIT cardio over a 24 hour snapshot.

Meanwhile with regards to the breakdown of muscle mass, HIIT cardio can actually produce an anabolic effect with regards to muscular hypertrophy (building muscle). Of course, significant amounts of HIIT cardio (or any cardio for that matter) will result in significant muscle atrophy (breakdown). But this simply is achieved through a caloric defecit - and could be just as effectively achieved through a diet deficient in calories.

It's very easy to get confused on this topic, particularly with the infamous "fat burning zone"...gah that is something I have a real beef about.

For more reading on the subject, check out these articles:

The Fat Burning Zone

(Begin with the one above, it's an article I had published in several fitness/bodybuilding magazines and provides a more general overview on the topic. The articles below analyse the subject in greater detail.)

Myths Under the Microscope - Fat Burning Zone

Myths Under the Microscope - Fasted Cardio

Myths Under the Microscope - Final Discussion