Steady State Cardio Or HIIT For Fat Loss: Which Is Best?
We Take A Detailed Look At Jogging and HIIT To See Which Is Better At Shedding Fat
This debate has been going on for a long time; as long as fitness, bodybuilding and strength sports have been around in fact. Which form of cardio is better: steady state running, or high intensity interval training (HIIT)?
Of course, at the time when bodybuilding was just beginning to grow as a popular sport or passtime (around the 1950s), the acronym HIIT wasn’t used. But the idea was still hotly contested.
To keep fat off, is it better to run for a long period of time every day (or every other day), or is it better to do very intense, repeated bouts of sprints a few times per week?
There has been a great deal written on this topic over the past few decades. Now, with so many internet blogs dedicated to bodybuilding and athleticism, there is almost far too much information for anyone to really take in, let alone for anyone to distill and evaluate.
Some bloggers will tell you that one way is definitely superior than the other as far as fat burning potential goes. Others will tell you that neither is good, and that you should follow their special, unique workout instead to really shed body fat.
To help you ‘cut through the fat’, we’re going to look at both sides of the argument and attempt to look at it from an impartial, rational perspective. We will try to see if there is any real difference between the two forms of cardio, and if so, how big that difference is. In the end, we’ll try to say whether we think either one is better for burning body fat than the other.
Steady State Cardio
To begin, we need to explain exactly what we mean by steady state cardio.
Steady state, low-intensity cardio is often defined as exercise which keeps your heart rate fixed at about 60-70% of maximum; so under 145. For the majority of you it will mean a fixed heart rate of 130-140 bpm.
Steady state cardio has really fallen out of favor over the past few years. If you were to tell a bodybuilder in the 1960’s that nobody on the Olympia stage ever does cardio for any real length of time, they’d probably assume you were lying.
So why has steady state cardio fallen out of favor?
To listen to some ‘experts’, you’d just assume that it was because we have found more effective methods of doing cardio. Some people even suggest that steady state cardio has practically no fat burning benefit whatsoever, and that those old-time bodybuilders were just wasting their time.
For instance, check out this piece over on Breaking Muscle. Reading this, you get the impression that steady state cardio is useless when it comes to getting leaner. To use their own words, steady state cardio burns more fat relatively, but not absolutely, although what this means exactly is never fully explained. We are just then told that steady state cardio doesn’t burn very much fat at all; the equivalent of “throwing a deck chair off the Titanic”.
Some people go even further. This article, published by the Poliquin Group editors, clarifies their pronouncement that “aerobic exercise is a fat trap”. While they make it clear that they are not saying cardio actually directly causes fat gain (as some of their readers apparently took their statement), they do suggest that steady state cardio can make fat gain more likely.
They make a number of statements to clarify their position and they quote scientific studies to justify these claims, as the guys at the Poliquin Group always do. Here are some of them:
The article goes on to quote more studies which purport to show people actually gaining fat while doing moderate, steady state aerobic exercise for a number of years. The editors then draw the conclusion that aerobic exercise doesn’t help us shed body fat, or even keep it off; quite the opposite.
So what are we to take from this? Should we drop steady state cardio from our routines altogether? Is it holding us back from better, leaner gains?
No, we don’t think so.
A More Balanced View?
As always on this site, we will try to take a step back and think about whether the information we’re being presented with is applicable to us, and whether or not it really entails the conclusions we’re being asked to draw.
We believe the articles cited above, and many like them, regularly focus in on very specific points about steady state cardio and use them to draw general conclusions. They don’t try to look at the big picture:
They often look at how little fat is burned during steady state cardio. Yet what is most important to us is total calories burned over a long period of time. Doing moderate aerobic exercise doesn’t burn many total calories. Particularly in comparison to some other forms of exercise. But other forms of exercise lack one awesome property of steady state cardio: you can do it pretty much every day. Even after a grueling deadlift session, we can still get out for a short, 20 minute run the next day.
So throwing a deck chair off the Titanic is nothing compared to throwing 20 deck chairs off the Titanic. But it is more valuable if you throw one deck chair off every single day for 4 months or throw 20 off just the once.
They look at how, if someone doesn’t increase the amount of cardio they do, and if they allow muscle mass to steadily decrease, they can actually make fat gain more likely. They claim this is because the body adapts to the level of exercise. Yet visitors to this site are highly unlikely to use steady state cardio as their primary form of exercise, and they are even less likely to let their muscle mass steadily decrease over time.
The majority of our readers will either do intense weight training or calisthenics multiple times per week; some form of cardio will be used to speed up the fat loss process when it is time to shed a few pounds. They will not be steadily losing muscle mass, and they will not necessarily grow accustomed to the cardio that they are doing because their body is being placed under a great and greater strain each week in trying to recover form increasingly intense training sessions.
Now that we’ve shed a little pessimism on some of the criticisms of steady state cardio circulating the internet, we’ll turn to some of the established, undeniable benefits of this form of cardio.
For starters, running (in a steady state sense) does lead to greater fat loss over the long-term than doing nothing, or even compared to walking regularly.
This study, published in Medicine & Science In Sports & Exercise, compared the weight loss observed between a large group of runners and a large group of walkers over a 6 year period. Subjects lived in free, non-experimental conditions (as you would expect for 6 years). The results of this study were pretty damn compelling:
“Although ΔBMI was significantly associated with both ΔMET-hours per day run and walked, the ΔBMI was significantly greater for Δrunning than Δwalking.” So a change (Δ) in BMI was associated with how much running and walking a person did per day, but overall the changes were significantly larger in the running group.
Another study, published in 2004, looked again at people who do no exercise, those that walk regularly, and those that job regularly. The results here match closely with the study cited above. The researchers concluded: “The major finding of the present study was that there was a clear dose-response relationship observed between amount of weekly exercise and amount of weight change.”
So it is clear that running does have some effect on body fat levels, contrary to what some online experts might tell you. It is also clear that this effect is greater than doing lower intensity forms of exercise, such as walking. It is abundantly clear that it is better than doing nothing.
For most of you, this will just make intuitive sense. Weight gain and loss is essentially an energy balancing act. If you take more energy in than you need, you’ll gain weight. If you take in less than you expend, then you’ll lose weight. You have control over both variables, so it is a matter of switching them around until you find the balance you’re looking for.
But that isn’t what most of you are interested in.
Steady State Cardio & Building Lean Muscle Mass
A fair amount of our readers aren’t interested in weight loss, they’re interested in fat loss. Most of these people are actually interested in getting bigger and more muscular over the long-term, but keeping fat gain to a minimum. For this group, steady state cardio still has some great advantages.
For starters, no matter what your situation, losing or gaining fat is still a balancing act. And no matter what your totally-super-qualified personal trainer tells you, your body will not go straight to your muscles to get its fuel for steady state cardio. A body designed to shed muscle tissue the moment it was mildly stressed would not be long for this dog-eat-dog world.
When running for an extended period, your body will use oxygen and sugar as its primary fuel sources (hence aerobic exercise). Make no mistake about it; aerobic activity is fueled by glycogen reserves, fat stores, or more usually, a combination of both.
So adding some steady state cardio into your weekly routine while bulking up can really help take the edge off some of the fat gain that’s inevitable while gaining muscle mass.
Another, more important benefit for strength athletes, bodybuilders, and so on, is the carryover benefits of steady state cardio; namely, increased work capacity and muscular endurance.
Having a better performing cardiovascular system, more muscle cell mitochondria, and more efficient lactate cycling can only improve your performance in the gym. There isn’t one instance I can think of where an athlete couldn’t benefit by being a little more ‘in shape’ (modern bodybuilding perhaps the only exception here). Shorter recovery periods mean more intense, more productive lifting sessions. Better lactate cycling means less cramps, longer sets, and more reps done over the long-term.
Finally, steady state cardio is perhaps the best, easiest form of active recovery out there. Rest days are important, sure, but it’s an undeniable fact that going for a short run the morning after doing a heavy bench session will both burn more fat over the long-run and improve recovery by pushing extra blood and nutrients to the damaged muscle tissue.
Now that we’ve covered the benefits of steady state cardio for losing fat and (yes, that’s right) building muscle mass, we’ll turn our attention to every online guru’s favorite form of cardio: high intensity interval training (HIIT).
First of all, what do we mean by HIIT exactly?
Strictly speaking, high intensity interval training is defined as a training method where you give short bursts of all out, 100% effort, be it sprinting or peddling at max speed on a bike. You should get your heart rate up to maximum output during these intense bouts.
These intense bouts are followed by intervals (get it?) of active recovery. Typically, it means walking.
Length of intervals and bouts of intense effort vary, but people usually start with 30 second sprint and 2 minutes walking.
A good place to begin looking at the benefits of HIIT is the work of Stephen H. Boutcher. In 2011 he published quite an extensive literature review which focused on the effects of HIIT on fat loss, insulin resistance, fitness, and skeletal muscle tissue. For now, we’ll focus on its effect on fat loss, but we will turn to its effect on skeletal muscle tissue later on.
There is an awful lot of scientific evidence that HIIT is incredibly effective at reducing body fat.
Take this study for example. The researchers looked at the effects of various forms of exercise on “body fatness”. In their concluding remarks, they state: “vigorous exercise favors negative energy and lipid balance to a greater extent than exercise of low to moderate intensity. Moreover, the metabolic adaptations taking place in the skeletal muscle in response to the HIIT program appear to favor the process of lipid oxidation.” Obviously here vigorous exercise refers to HIIT.
Another trial looked at the effect of just 2 weeks of HIIT on the body fat levels of relatively active women. It found that “seven sessions of HIIT over 2 wk induced marked increases in whole body and skeletal muscle capacity for fatty acid oxidation during exercise in moderately active women.”
Yet another study published in Applied Physiology, Nutrition and Metabolism in 2008 found that “18 h of repeated high-intensity exercise sessions over 6 weeks (3 d.week-1) is a powerful method to increase whole-body and skeletal muscle capacities to oxidize fat and carbohydrate in previously untrained individuals.”
Now of course, some of these trials have their limitations. The final one in particular demands some skepticism as it looked at previously untrained individuals. Such people do not require a great deal to stimulate fat loss, and they are unlikely to serve as a good bellwether for visitors to this site.
But still, this is one study out of many. Do some research of your own and you wont struggle to find studies supporting the notion that HIIT effectively increases fat loss. Much of the literature compares HIIT and steady state cardio directly, and rules in favor of the former.
HIIT & Building Lean Muscle Mass
The main reason why bodybuilding enthusiasts now increasingly turn to HIIT for their form of cardio (especially when cutting) is because it supposedly protects muscle mass to a significant degree, whereas steady state cardio supposedly diminishes muscle mass as well as body fat. Many go as far as to suggest that HIIT does not diminish muscle mass at all when used as a fat loss technique.
This is a prime example of a half-truth being repeated again and again until it becomes accepted dogma.
Yes, HIIT does seem to burn fat and support the retention of lean muscle mass to a significant degree.
No, it does not mean that you retain ALL of your muscle mass while cutting if you do HIIT instead of steady state cardio.
No, steady state cardio does not quickly eat into existing muscle mass.
First of all, if you’re losing weight, unless you’re an untrained individual, you are going to be losing muscle mass. You simply can’t eat into your fat reserves if you aren’t eating a caloric deficit. And if you’re eating a caloric deficit, you can’t build lean muscle tissue.
That is an undeniable fact of life for natural athletes of any kind.
So just because you do high intensity sprints twice per week while cutting doesn’t mean you’ll be holding onto all of your gains. Not at all. You will lose muscle mass.
That said, it does seem that certain types of HIIT lend themselves to maximal muscle mass retention.
Take this study, which compared two modes of endurance training and their effect on strength levels.
These researchers found that ” the mode of endurance exercise in concurrent training regimens may play a role in the development of strength.” Here you can read strength as “muscle mass retention”, as losing muscle mass almost invariably means a reduction in strength for almost all people.
They were more specific about their findings: “cycling is superior to treadmill endurance training for an individual with the goal of developing strength in a multijoint movement (i.e., leg press or squat) in the lower-body because it more closely mimics the biomechanical movement of these exercises.”
Another study, conducted on hockey players in 2015, turned up even more impressive results.
In this study, hockey players were divided into two groups; a continuous cardio group (CG) and a high intensity interval group (IG). Body composition, muscular thickness, anaerobic power, and on-ice measures were assessed. The results showed that the IG had greater improvements in muscle thickness and power output.
But you must bear in mind that these are relative measurements. HIIT does seem to be a good choice for preserving strength and muscular thickness while trying to reduce body fat, but that does not mean that you are able to retain all of your muscle mass while doing high intensity interval style training.
It also does not mean that doing any other form of cardio, such as steady state, will destroy your gains. While HIIT seems to be better than steady state for preserving muscle mass, the difference is often marginal and dependent on other factors such as diet and training protocol.
HIIT and Conditioning
In our steady state section we spoke about steady state’s ability to make you perform better in the weight room. So it’s only fair we give the same consideration to HIIT.
Steady state cardio increases endurance and work capacity. We might measure the latter by monitoring VO2max, which is the maximum oxygen uptake while exercising.
A study often quoted by HIIT champions is this one, published in Sports Medicine (New Zealand) in 2015. Many self-styled gurus rightly claims that this study found “gains in VO2max being greater following HIT when compared with endurance training.”
But if you read the actual results, you’ll see that “When compared with endurance training, there was a possibly small beneficial effect for HIT with small additional improvements for typically longer HIT repetitions”.
These results have been replicated elsewhere.
A 2015 paper published in the Journal of Sports Science and Medicine looked at the effects of HIIT vs steady state cardio training on both aerobic and anaerobic capacity. What they found was “no significant differences between groups.”
In the end, the researchers concluded: “The results suggest that although HIIT protocols are time efficient, they are not superior to conventional exercise training in sedentary young adults.”
So let that be a lesson to you; don’t take conclusions at face value. Always read the fine print!
Final Verdict – Which Is Better For Fat Loss?
Ultimately, it seems that the divide between these two training methods has been somewhat exaggerated.
Is HIIT a good cardio option for a bodybuilder? Absolutely!
Is steady state cardio a good cardio option for a bodybuilder? Absolutely!
Both forms of cardio contribute to fat loss.
Neither will eat up your muscles for fuel, despite what some people tell you on the internet.
Both contribute to greater aerobic and anaerobic capacity, leading to longer, more productive sessions and better gains.
So which should you do?
In our opinion, having weighed up the evidence, we think you should just do whichever is easier and more enjoyable for you. While HIIT can be fun for a while, few people can keep it up for longer than a few weeks. It is incredibly exhausting, and unless your ability to recover (by that we mean eat and sleep) is excellent, it may be counter-productive. In that case, steady state might be best.
But some of you will no doubt hate the long slog on the treadmill, even if it is for just 20-25 minutes. In that case, give HIIT a whirl.
You also need to consider what you mean by “intensity”.
For some of you, your running speed and distance is an incredible workout. For others, what you might call “high intensity” is to me a walk in the park.
So it is all well and good saying “HIIT is better than steady state cardio for fat loss”, but that depends on the intensity and the time exercised for.
Is 1 lazy sprint as good for fat loss as a 30 minute run? No. Specifics matter here. You cannot simply say that one is better than the other. You need to specify what your HIITs are like and what your steady state is like. Only then can you make a genuine comparison.
Be realistic with yourself and you will find the method that works best for you.