Here’s a joke for you…
What do you call a nervous javelin thrower?
Here’s another one:
Fasted cardio burns more fat.
I know… I know…
For years, we have been told we have to wake up at F**k O’ Clock in the morning and pound the treadmill to lose some blubber – and it’s total bulls**t.
In this post, I’ll show you why
Fasted Cardio Explained
I’m not bashing fasted cardio.
In fact, I like it.
I like feeling lean AF right after a quick morning workout. And also the prospect of getting into a calorie deficit before the day has even really started.
Russ 1 – Calories 0…
And hey, it definitely works for fat loss.
Because you will still burn calories during your workout. And you will lose fat, as a result of said calorie burn.
However, problems arise when people believe fasted cardio is better than regular fed cardio (i.e. doing this will burn more fat than doing that).
It isn’t better.
It’s just a different way of doing the same thing.
This was shown in a 2000 study published in the Journal of Applied Physiology where, contrary to expectations, researchers concluded that training in a fasted state caused no improvements to fat loss. (1)
Further still, it was expertly doubled-down on in 2011, when Dr. Brad Schoenfeld conducted a thorough meta-analysis of the available body of research on this subject (published in the Strength and Conditioning Journal).
After looking at every shred of evidence ever recorded, the conclusion was once again that fasted cardio isn’t superior for burning fat. (2)
That’s a statement the American Council of Exercise agree with, and it’s also been shown in clinical trials performed more recently, too. (3, 4)
The research from that meta-analysis is thoroughly explained in this article, if you’d like to read it, but the crux of the matter is that overall energy balance is what causes fat loss; not variables like training fasted or fed.
Meaning if one guy ate 2000 calories and performed fasted cardio, but another guy ate the same 2000 calories yet did fed cardio, neither would unlock superior results.
Why Do People Believe Fasted Cardio Will Burn More Fat?
This is partially down to flawed science, and also so-called “experts” who continue to tell people this myth is true.
Let’s look at the science first…
A 2019 study from UK researchers claimed that “Skipping breakfast before exercise causes more fat loss.” (5)
It was hailed as proof that fasted cardio burns more fat…
… and that would be a huge deal…
… but when we go deeper, the flaws immediately come to light.
Remember the example I gave above about two guys eating the same calories, but one doing fasted cardio and the other doing fed cardio?
Yeah, this study did not do that.
They literally had one group of participants consuming one less meal per day (skipping breakfast), and they wondered how they were able to lose more weight!!!
Research like this only serves to confuse people.
Of course, I also mentioned “experts” who continue to push this fasted cardio myth out there to the world.
These guys are just as guilty, because they should know better.
After all, when someone like Jennifer Lopez posts that she’s started doing fasted cardio, I dread to think how many people started copying in the hopes of achieving that body (which she already had, for the last 25 f**king years).
But you know what?
I’m not even mad at celebrities.
After all, they talk s**t all the time. A year ago, they were all buying cleansing rocks from Gwyneth Paltrow and shoving them up their hoo-haa.
So there’s that.
Nah, what really bugs me is when fitness professionals push the fasted cardio myth…
Here’s an example.
The Perfect Physique, featured on Netflix.
If you haven’t seen it, it’s a documentary in which a group of cover models discuss their training regimen and the type of diets they use when preparing for a shoot.
Given the large potential audience of any show on Netflix, you’d think the program would stay clear of any advice which may mislead casual gym goers into believing things which aren’t true, right? Stick to the facts?
Yeah, not so much.
What we get is a 90 minute plethora of fitness myths. Like a kinda domino effect for outdated advice.
During one rather heated debate, a young model states he prefers to do his morning cardio in a fed state because he has more energy.
The rest of the group recoil in shock and awe:
Aren’t you worried that you’re only burning the meal you just ate and nothing else?!”
It was at this point, that I was fixing to one inch punch my television.
Because that’s not how any of this works.
If it was, how would anyone who trains in the PM lose any weight? They’d just be burning through that days food!
But as with all bulls**t fitness myths, one leads straight to another…
Later, these guys insist you must eat every 2-3 hours to prevent muscle loss. And they do this while conveniently ignoring the fact that they put themselves into an 8 hour fast every night (sleep) then jump on a treadmill!
These are your experts, folks.
Surely an 8 hour fast followed by a workout would lose stacks of muscle, if you were going to lose muscle by failing to eat for 2-3 hours, right?
“No, because I take BCAAs to prevent muscle breakdown during fasted cardio.”
I’ve officially ran out of evens to can’t.
As broken down in this article, if someone take BCAAs before fasted cardio, they are no longer doing fasted cardio.
And this is just one unlucky show I’m picking on here, but these myths are buried deep into the psyche of the fitness industry – it’s a prime example of why you shouldn’t listen to every guy at your gym who happens to be in shape.
How To Get The Best Results
Here’s the thing…
Fasted cardio works.
You will still burn fat. You just won’t burn more fat.
The theory of why fasted cardio should burn more fat makes sense… in theory.
With no carbohydrates to burn, we will have no choice but to shovel fat into the fire as we train… but like many theories, it doesn’t pan out the way we hoped it would.
Because despite what insta-famous models spout on the daily (#neverstopnotgivingup #fastedcardio), there is no “trick” to suck body fat into the space-time continuum, nor to defy how the law of thermodynamics works.
If there’s one thing the research on this matter shows us, it’s that humans are incredibly complex creatures.
Our body is capable of adapting to its surroundings in order to survive and thrive.
So while we may indeed burn fat during our fasted cardio workout in the absence of carbs, it appears the body is able to balance this over the course of the day by burning more glucose once we re-feed.
Meanwhile, those who train in a fed state will burn more carbohydrates during training, because they are present, but will again even out the balance by burning more fat throughout the rest of the day.
So do the one you like the most!
The only exception to the rule here is high intensity interval training.
Many of you know I’m a big advocate of HIIT.
Heck, I developed an entire workout plan on it then watched countless numbers of you get in unreal shape with it.
But HIIT is designed to be performed in a fed state.
With a lack of fuel (particularly carbs), your bouts will be less productive and your overall calorie burn will be significantly lower. (6, 7)
Tackle any of my HIIT circuits in a fasted state, and you can expect to crawl outta the gym like an extra from Z-Nation!
If you’ve enjoyed my breakdown on why fasted cardio doesn’t burn more fat, share it on your socials (might start a war, though), and jup o my free email list at the bottom of this post for future training tips.
- Febbraio, M. A., et al. Effects of carbohydrate ingestion before and during exercise on glucose kinetics and performance. (2000)
- Schoenfeld, B. Does Cardio After an Overnight Fast Maximize Fat Loss? Str Cond J. (2011)
- Hackney, K.J., et al. Timing Protein Intake Increases Energy Expenditure 24 H After Resistance Training. Med Sci Sports Exerc. (2010)
- Paoli, A., et al. Exercising Fasting Or Fed To Enhance Fat Loss? Influence Of Food Intake On Respiratory ratio And Excess Post Exercise Oxygen Consumption After A Bout Of Endurance Training. Int J Sport Nutr Exerc Metab. (2011)
- Edinburgh, R. M., et al. Skipping Breakfast Before Exercise Creates a More Negative 24-hour Energy Balance: A Randomized Controlled Trial in Healthy Physically Active Young Men. The Journal of Nutrition. (2019)
- Wright, D. A., et al. Carbohydrate feedings before, during, or in combination improve cycling endurance performance. J Appl Physiol. (1991)
- Schabort, E. J., et al. The effect of a preexercise meal on time to fatigue during prolonged cycling exercise. Med Sci Sports Exerc. (1999)