HIIT or Steady Cardio: What Burns More Fat?

Its a common debate, and everyone has their preferences. But what does the science say? Let's discuss high intensity interval training vs steady cardio workouts and see which style burns more fat.

It’s a debate that’s been going on for a long time. Who burns more fat: stick-thin marathon runners doing long steady cardio or ripped weightlifters who use high-intensity interval training (HIIT)?

The question is a contentious one because both are valid forms of exercise and both can help you lose fat. However, we’re getting close to determining which one burns more fat – and it might be HIIT. Rather than considering opinions, we’d rather look at the science.

The Case for Intensity: HIIT

The recent focus on HIIT and other training systems like it seem to be getting more press than steady cardio.

That’s because recent scientific studies have produced data that supports HIIT as being better exercise.

Several studies have found that when people combine resistance training with aerobic exercise, their bodies are more likely to work harder and more likely to see more positive effects like better cardiovascular fitness and lower risks for cardiovascular disease.

If you’re working harder to improve your cardio, then you’re burning more calories and more fat.

Of course, these studies are small, so the generalizations to be made about the findings are limited. But it goes to show that the spectacle the fitness industry has made of HIIT is based in a reality.

The fine print tends to find that HIIT isn’t miles better than steady cardio. It’s only mildly better. And when you consider how much harder HIIT can be physically, you have to wonder whether it’s worth the effort.

But what about burning fat and losing weight?

Mixed Results: HIIT vs Cardio

One recent study explored which of the two is better for weight loss.

The study was conducted by researchers at Duke University. They spent eight months tracking 119 volunteers who were both overweight and previously sedentary.

Volunteers participated in either aerobic exercise, resistance training, or a combination of aerobics and resistance training. When the researchers weight the volunteers at the end, it was the group who had participated in aerobics who lost the most weight.

The resistance group added two pounds to their starting weight. Before you ask – yes, they gained muscle mass, which contributed to the weight gain.

But what was most interesting about this study, especially compared to the studies about cardiovascular work we listed above, was that the fat loss and muscle mass found in the resistance training group wasn’t meaningful enough to suggest that it is a superior form of exercise.

Why Is HIIT So Popular? The “Afterburn”

If running, resistance, and HIIT all seem to produce similar effects – at least, they’re not different enough to say one is definitively better than the other – then why is HIIT so popular?

What makes it different?

The answer to this question is afterburn, which is fitness-industry slang for excess post-exercise oxygen consumption (EPOC). EPOC is the amount of oxygen your body consumers after exercise. If you’ve exercised heavily, you’ll need more oxygen. ‘Afterburn’ links the oxygen consumption to burning more calories after exercise.

In other words, if you work out hard, you’ll not only burn calories during your workout but you’ll burn more calories than you normally would in the hours and days afterward.

Who doesn’t want that?

The story goes that HIIT has greater afterburn than steady state cardio. However, the jury is out here, too, because the studies that suggest that HIIT increases EPOC are also vague. The effects of EPOC are modest, and the effects of HIIT on EPOC are also modest. They’re not enough to definitively say HIIT blows the benefits offered by cardio out of the water.

Add in Weight Training

While it’s unclear whether HIIT or cardio alone has great effects on your cardiovascular system, EPOC, and fat loss, there is one thing that does.

If you’re looking to destroy fat with one of these devices, then weight training is the way to go. While the gains you enjoy can vary wildly depending on intensity, how much muscle you have, and what exercise you’re doing, science shows that lifting weights is the best way to go.

That’s not to say that cardio and HIIT have no place in fat loss. They’re both viable ways of losing weight and getting healthy. But if you’re looking for the fastest way, you’ll likely need to throw in some weight training.

HIIT vs Cardio: The Best Way to Battle Fat

If you’re looking for a scientifically-proven way to burn fat, then either HIIT or steady cardio will work. While one isn’t substantially better than the other, both are able to burn fat, improve your cardiovascular system and help you feel better.

Reading this and haven’t exercised in a while? Start with aerobic cardio exercise.

Aerobic cardio exercise, like dancing, jogging, swimming, or cycling, will help you build up your cardiovascular system up to a point where you’re ready to take on intense training systems like HIIT.
Once you’re feeling ready for HIIT both physically and mentally, start with two sessions a week and keep it up for a few months.

You might be tempted to hit the gym every day. More exercise burns more calories, right?
Resist the temptation. HIIT can take a toll on your body, and it’s something that should be thrown into your workout for a few weeks or months and then taken out again for recovery.

In fact, there’s no reason not to go back to steady state cardio or weightlifting in between sessions, since you’ll still be burning fat.

Do What’s Right for You

The jury is out on whether HIIT is really better than steady cardio. While science has shown that HIIT offers slightly elevated benefits, the evidence isn’t likely enough to demonstrate a serious improvement in fat loss.

So, what workout should you choose?

Get involved in workouts that make you happy, help your body feel stronger and healthier, and make you look better.

What’s your experience with HIIT and cardio? Did you find one worked better than the other? Share your stories in the comments.

TFT Team

Our team at The Fitness Tribe often collaborates together to produce content. When you see “TFT Team” this is because the content was not written by a single author, but rather a team effort.

Let's discuss high intensity interval training vs steady cardio workouts and see which style burns more fat.