Share On

Doing cardio on an empty stomach doesn’t necessarily help you lose fat faster.

Doing fasted cardio can help you lose fat–and “stubborn” fat in particular–faster, though.

(And it works especially well when combined with several other fat loss strategies, which we’ll talk more about in this podcast.)

This sword cuts both ways, though.

Do your fasted cardio wrong and you won’t lose fat faster. You’ll just lose muscle instead, which is a good way to wind up skinny fat.

We’re going to break it all down in this podcast and learn the simple science of fasted cardio, including…

  • What fasted cardio actually is (and isn’t).
  • How it can help you lose fat faster.
  • Why it can cause muscle loss.
  • How to maximize its benefits (fat burning) and minimize its drawbacks (catabolism).
  • What types of fasted cardio are best.
  • And more.

By the end, you’ll know how to use fasted cardio to speed up fat loss without sacrificing muscle.

So let’s go. 🙂

Would you rather read about fasted cardio? Then check out this article!

Oh and if you like this episode want to be be notified when new episodes go live, then head on over to iTunes, Stitcher, YouTubeSoundcloudSpotify, iHeartRadio, or Google Play and subscribe.

Lastly, if you want to support the show, please drop a quick review of it over on iTunes. It really helps!

Time Stamps:

5:52 – What is fasted cardio?

9:10 – How does fasted cardio affect fat loss?

11:37 – What does the science say about burning more fat with fasted cardio?

18:54 – How does fasted cardio affect calorie burning?

21:11 – What is stubborn fat?

26:39 – What is yohimbine?

33:30 – What is synephrine?

34:52 – What type of fasted cardio is best?

40:30 – What about fasted weightlifting?

43:49 – How do you maximize the effectiveness of fasted training?

46:39 – What is HMB?

55:21 – What I take before fasted training?

56:51 – What should you eat after fasted training?

60:32 – What’s the bottom line on fasted cardio?

Episode Transcript:

[00:00:30] Good day, my friends, this is Mike Matthews from Muscle For Life and Legion Athletics. And in this episode of the podcast, we are going to talk about fasted cardio and fat loss. Does it actually help you lose fat faster? Does it accelerate muscle loss? Should you do it? You are going to learn the answers in this episode.

[00:00:52] Okay, so whether you enjoy cardio or not, you probably know that it does help you lose fat faster. It increases energy expenditure, which of course speeds up fat loss. Now, on the other hand, you probably also know that doing too much cardio makes it harder to make muscle and strength gains and can also accelerate muscle loss and strength loss when you’re cutting.

Therefore, the more you care about your body composition, the more you might give some thought to how you can reduce the minimum effective dose of cardio required to get the body that you really want. That is my general position on cardio. When people ask me do they need you to do cardio? How much cardio should they be doing?

My standard answer is to do as much cardio as you need to reach your body composition goals and not more unless you really enjoy it. And for most people, I like to use the 80/20 framework just because it’s something that people are familiar with and it has practical value.

So what I tell most people is take the time that you have to exercise every week. For most people, it’s like three or five hours a week. And I would prefer that you spend 80 percent of that time training your muscles, doing some sort of resistance training.

And if I had my way, it would be weightlifting. And then the remaining 20 percent, you can give to cardio because cardio does provide some health benefits that you can’t necessarily get from resistance training, namely cardiovascular benefits.

[00:02:33] So what we’re looking at then really is: how can you reach your fitness goals while doing as little cardio as possible? And many people say that fasted cardio helps here because it burns significantly more fat than fed cardio or non-fasting cardio.

It’s also commonly claimed that fasted cardio is particularly helpful for eliminating the stubborn fat covering your stomach, your love handles, and lower back. That’s mostly for us guys and for women, it’s usually the butt, thighs, and hips.

[00:03:10] And then there are people out there that disagree completely. They say that fasting cardio does not help you lose fat faster and actually makes it harder to get the body that you want because it accelerates muscle loss and it makes your workouts a lot harder than they need to be.

[00:03:29] So who is right? Well, both actually. Both the advocates and the naysayers are right to a degree. And both are also wrong to a degree.

[00:03:43] The truth is that fasted cardio can not help you lose fat faster, but it can help you lose stubborn fat faster if you do it right.

[00:03:56] If you do it wrong, though, then all you are likely to get out of it over traditional fed cardio is smaller and weaker muscles.

[00:05:52] Okay, so the first question that we have to answer in today’s discussion is: what is fasted cardio? Now, many people think that it is simply exercising on an empty stomach, which they usually think is simply a stomach that just feels empty. Now, it’s a bit more than that. Fasted cardio is cardio done while in a fasted state wherein your stomach is empty, but it has also to do with how your body has processed and absorbed the food that you last ate.

[00:06:30] You see when you eat food, it gets broken down into various molecules that your cells can use and these molecules are then released in your blood. The hormone insulin is released as well and its job is to shuttle these molecules into cells so they can be used.

Now, when your body is digesting and absorbing what you have last eaten and insulin levels are still high, your body is in a fed or post prandial state. That’s the technical term. Prandial means having to do with a meal, so after a meal. Once your body has finished processing and absorbing the nutrients from the food, insulin levels naturally drop to a minimum low or baseline level. And your body then enters the fasted or post-absorptive state. That’s the technical term.

[00:07:25] Now, how long it takes for insulin levels to fall back to this baseline depends on the size and the composition of your meal. Larger meals that include a mix of protein, carbs, fat, and fiber digest slower than smaller meals that are mostly composed of one or two macronutrients like an apple, for instance, which is mostly carbs.

[00:07:49] So for instance, in one study, it was found that after eating about 600 calories of pizza, that provided about 37 grams of protein, 17 grams of fat, and 75 grams of carbs, insulin levels were at double the baseline level for at least five hours.

Now, on the other hand, if you eat a smaller, much simpler meal, like, let’s say a single scoop of whey protein isolate, which only contains about 100 calories, 20 grams of protein and trace amounts of fat and carbs, insulin levels will fall back to baseline within a few hours, two to three hours or so. Now your body moves in and out of these fed and fasted states several times a day. So timing your exercise correctly is the key to doing true fasted cardio.

[00:08:46] So just to recap here with the first piece of our discussion: exercise done during periods where insulin levels are elevated and food is still being processed and absorbed, is fed training; and exercise done during periods where insulin is at a low baseline level and food is no longer being processed and absorbed is fasted training.

[00:09:10] Okay, so now that we know what fasted cardio is, let’s look at what science says about how it impacts fat loss. Now, the reason many people believe that faster cardio increases, fat loss has to do with insulin. So I mentioned earlier that insulin shuttle’s nutrients into cells, which is true, but it also does more than that.

It also impairs the breakdown of fatty acids. In other words, the higher your insulin levels are, the less your body is going to use fat for energy. And that means both body fat and dietary fat.

[00:09:52] And if you think about it, it makes sense physiologically. Why burn fat? In the case of body fat, that’s an energy store and it’s a vital energy store that is there to keep us alive. If food were ever to disappear and we ever had to go back to our ancient days and go roam around for animals to kill, and you know, in olden, olden times, we might go for days and days without food, and then finally kill an animal and then have to feast, and then store fat and survive on that for another, who knows how long, until we find food to get?

So why burn that when there is a surplus of energy readily available via the food that we just hate? Therefore, when you eat food, your body basically shuts down its fat burning mechanisms and just uses the energy provided by the meal.

And it also stores a portion of the excess energy not immediately needed for survival as body fat for later use. Now as your body processes and absorbs that food in some levels decline, which then tells the body to start burning body fat for energy as the fuel from the meal is running out. And then finally, when the absorption is complete, your body is running almost entirely off of its own body fat stores for energy waiting for the next meal.

[00:11:21] Now, the rationale for fasted cardio is that by doing your workouts in a fasted state, when your body is already running on mostly body fat, you can burn more total body fat than if you did the same workouts in a fed state. So that’s the theory.

[00:11:38] What does the science say? Well, actually, there is little doubt that fasted cardio does indeed burn quite a bit more fat than fed cardio. So, for example, in 2016, a group of scientists from Federal University of Rio Grande do Sul in Brazil looked at 27 different studies on this topic and concluded that, “aerobic exercise performed in the fasted state induces higher fat oxidation than exercise performed in the fed state.”

And the main reason for this is simple: it is very easy for the body to convert carbohydrate into fuel during exercise. So when more carbohydrate is available, as is the case, after eating a meal containing carbs, your body is going to burn more carbs and less fat for fuel. And this is why a number of studies stretching back to the 1970s have shown that when you give people carbs before or during exercise, they burn more carbs and less fat during their workouts.

[00:12:52] So we know that training in a fasted state does cause you to burn more fat during your workouts. So far, so good. We also know, however, that the number of calories that you burn during a workout is just a fraction of your total daily energy expenditure, which is really what determines how much fat you lose.

So the real question is, does the slight increase in fat burning during a fasted workout – and when I say slight, I’m saying it’s slight in the overall scheme of things, it’s actually significant if you’re just looking at how much fat is burned during the workout, during a fasted workout versus a fed workout, but it’s slight in terms of your total fat loss for the day, or you can look at it for the week, however you want to look at it in terms of time – so does the increase in fat burning during your fasted workouts, does it actually translate into a significant increase in total in overall fat loss over the course of a day, a week, and so on?

Well, that is what a group of scientists from the University of Padua wanted to find out in a study that they conducted in 2011. And in this study, they split eight men into two groups. Group 1 ate breakfast before their workout and Group 2 ate breakfast after their workout.

And for the workouts, everyone ran on a treadmill for 36 minutes at a moderate pace. And the researchers measured what percentage of calories the subjects were burning from carbs versus fat before and then 12 and 24 hours after their workouts.

Now, as expected, the fasted workouts did result in more fat loss. The guys who trained in a faster state did burn more fat during those workouts. However, later in the day, they burned significantly more calories from carbs and less from fat. And the group that trained in a fed state, they experienced the opposite when they were working out.

They burned more carbs during the workouts and then more fat during the rest of the day. And when the researchers average it all out, what they found is that both groups burned more or less the same amount of body fat and carbs throughout the day. Meaning that the fastest cardio actually offered no clear fat loss advantage.

[00:15:33] Now, why? Well, the body uses whatever fuel it has available for energy. And it also prioritizes nutrients in a specific order. Top on the list is blood glucose. And then after that is stored carbohydrate like muscle glycogen, for example, there’s also glycogen in your liver.

And then after that is stored body fat and then after that is stored body protein, which comes from muscle tissue. Therefore, when carbohydrate is readily available, the body prefers to burn that over body fat. And when less glucose is available, it prefers to rely more on dietary fat and body stores for its energy needs. So in other words, the body compensates for an increase in fat burning during fasted cardio with a decrease in fat burning during the rest of the day.

[00:16:35] Now, one shortcoming of this study is that it only measured fat burning over the course of a single day, which raises a question of whether or not it is possible that the group that did fasted cardio would have lost more fat than the fed group if they had kept this up for several weeks.

[00:16:54] Well, we have a study for that as well. That’s what scientists from Lehman College wanted to find out in a 2014 paper where they split twenty 20-year-old women into two different groups. Group 1 did their cardio workouts after eating breakfast, fed, and Group 2 did their cardio workouts before eating breakfast, fasted.

Both groups ate their last meal at least twelve hours before reporting to the lab to ensure that they were in a fully fasted state. And then under the supervision of the researchers, everyone did about an hour of jogging on a treadmill three times per week for four weeks.

And the scientists had both groups of people follow a diet that kept them in a 500 calorie deficit every day. And then at the end of the study, what the scientists found is that both groups had reduced their body fat percentage by about 1 percent. However, there was no significant difference between the groups.

[00:17:54] So once again, fasted cardio failed to produce more total fat loss over time than fed cardio. Fasted cardio also has another downside, which is that while it does result in more fat burning during exercise, that’s true, much of the fat isn’t the subcutaneous stuff that wiggles and jiggles when we walk.

Instead, research shows that about half of the extra fat lost during fasted cardio comes from fat stored in your muscle cells for easy energy. And to make matters even worse, the fitter you become, the more your body will tap into these intramuscular triglycerides, fatty acids, instead of going to body fat stored in other places that we care more about, like the stuff covering our abs, for example.

[00:18:54] Okay, moving on, let’s quickly touch on fasted cardio and calorie burning. So we know that fast and cardio does result in – fasted exercise in general, it could be resistance training – it does result in more fat loss and fat burning during the workouts, but not necessarily over time.

What about calorie burning? And although it’s implied in everything we just discussed. Let me just state clearly that fasting cardio does not help you burn more calories than fed cardio.

[00:19:25] And you can find evidence of this in a study that was conducted by scientists at the University of Tsukuba in Japan. In this case, scientists had twelve young male endurance athletes report to the lab and undergo both of the following protocols with one week in between each.

So the first protocol was an hour of easy indoor cycling after eating breakfast (fed cardio), and the other protocol was an hour of the same exercise protocol before eating breakfast (fasted cardio). The researchers kept all of the subjects locked in the lab for three days so they could carefully measure food intake, energy expenditure, and fat loss. And what they found is that there was no difference in the 24 hour energy expenditure between the groups.

[00:20:14] So the bottom line here is that fasted cardio just by itself is not going to help you lose fat faster over time than regular fed cardio. That said, when you combine it with the right supplements, it can help you get rid of stubborn fat faster.

[00:20:33] So let’s dig into that. If you’re a woman, you’ve probably noticed that your hips, your thighs, your butt are really the last places in your body to really tighten up when you’re dieting. And if you’re a guy, it’s almost certainly your lower abs, your love handles, and your lower back.

Now, the good news is this is not a genetic curse. It’s simply a physiological mechanism that your body uses to defend against very low body fat levels. And fasted cardio can help you overcome this obstacle and lose that stubborn fat faster.

[00:21:11] So let’s start first with a physiological explanation of what stubborn fat is. So your body uses chemicals known as catecholamines to trigger fat burning. So these chemicals, they travel through your blood and they attach to receptors on fat cells, kind of a lock and key mechanism. So the key is the chemical, the catecholamines.

And then you have the lock on the cells and the key fits in the lock and things happen. In this case, the cells release the energy for burning. Which means that fat cells, by the way, they shrink and they expand. So when you get fatter, it’s your fat cells expanding.

You are not in most cases, you are not gaining fat cells. They’re simply expanding with energy. And when you’re losing fat, they’re shrinking because their energy stores are getting whittled away.

[00:22:09] Now, fat cells, they have two types of receptors for these catecholamines and they’re called alpha and beta receptors. I don’t want to get too into the weeds here on the physiological details. But to keep it simple, beta receptors speed up fat mobilization, whereas alpha receptors hinder it.

So you had these catecholamines. They can bind to both beta and alpha receptors. If they bind to beta receptors, fat loss is sped up. If they bind to alpha receptors, fat loss is obstructed.

[00:22:41] So what that means is that the more alpha receptors a fat cell has, the more resistant it is to being mobilized by catecholamines. And on the other hand, the more beta receptors a fat cell has, the more receptive it is to these fat mobilizing molecules.

[00:22:59] Now, as you’ve probably guessed, the areas of your body that get lean very quickly have a lot of fat cells with more beta receptors than alpha receptors. In areas that do not, the areas that really don’t even seem to change much at all, especially in the beginning of a cut, they have a lot of fat cells with more alpha receptors than beta receptors.

[00:23:20] Another problem with these stubborn fat deposits on our bodies relates to blood flow. So you may have noticed that fat in certain areas like the lower back if you’re a guy, or the thighs if you’re a woman, are slightly colder to the touch than fat in other areas of your body, like your arms or your chest.

Now, this is simply because there is less blood flowing through these colder areas. And of course, less blood flow means fewer catecholamines that can reach the already now stubborn fat cells in those areas, which of course, then means even slower fat loss.

So what we have here is a double whammy of fat loss, hindrance. You have large amounts of fat cells that just don’t respond well to catecholamines and you have reduced blood flow that keeps those catecholamines away.

And this is why you can lose fat and you can lose weight steadily with almost all of the fat seeming to come from certain parts of your body that are already fairly lean.

[00:24:28] So, for example, if you’re a guy and you have gone through at least a few cuts, you’ve probably noticed that your chest, your forearms, and your calves, in some cases, your face tend to just get leaner and leaner; while your abs, especially the lower abs and your love handles and your lower back, those fat deposits refused to budge.

And if you’re a woman, you’ve probably went through the same experience, but more with your legs, abs, and arms tending to get leaner, at least the lower parts of your legs, and in your abs and your arms, while your butt and your hips and your thighs remain almost unchanged.

Again, at least for the beginning of cuts. Eventually, of course, everything leans out, but it takes time to get those stubborn fat deposits to shrink significantly.

[00:25:21] So what this means then is: once you get relatively lean, the more stubborn fat you can lose, the bigger the impact on your physique. Losing just a pound or two of fat from the right places on your body will do a lot more in the near than several pounds from areas of your body that are already fairly lean.

[00:25:44] Now, what does all this have to do with fasted cardio? Well, research shows that blood flow in the abdominal region in particular is increased when you are in a fasted state. And so that means that more catecholamines can more easily reach this stubborn fat easier, which can result in greater stubborn fat mobilization.

[00:26:08] So this means that while fasted cardio will not help you lose more total fat every day, it will help you lose at least some of the fat that you want to lose the most a bit faster. And this is especially true and becomes even more applicable to other regions of the body when you combine your fasted cardio with a few supplements, which include two in particular that I want to draw special attention to: yohimbine and synephrine. So let’s talk about those quickly.

[00:26:38] Let’s talk about yohimbine. Yohimbine is a supplement that’s made from the Pausinystalia Yohimbe plant and several studies have shown that it can speed up fat loss. And it does this by stimulating the production of catecholamines, which we recall trigger fat burning and which also speed up your basal metabolic rate and suppress your

[00:27:05] And a good example of how effective it can be can be found in a study that was conducted by scientists at the University Paul Sabatier in France. I probably mispronounced that. It’s probably “Sabatiay” or something, but I don’t speak French, so I’m going to be ‘Merican.

Anyways, in this case, researchers had six young men report to the lab and undergo both of the following protocols with one week in between each. The first protocol was consuming 0.2 milligrams of yohimbine per kilogram of body weight after an overnight fast.

And the second was to consume the same amount, 0.2 milligrams of yohimbine per kilogram of body weight after eating breakfast. And what happened is the blood levels of free fatty acids, so the amount of free fatty acids that were released from fat cells for burning, doubled when yohimbine was taken after the overnight fast, yet remained unchanged when taken after breakfast – which is interesting. And we’ll talk about why that is in a minute.

[00:28:11] Now, these same scientists also carried out another experiment on eight other men in the same study. And in this case, they had everyone undergo all three of the following protocols with one week in between each. The first was 0.2 milligrams of yohimbine per kilogram of body weight without any exercise.

The second was a placebo with 30 minutes of moderate-intensity, indoor cycling. And the third protocol was 0.2 milligrams of yohimbine per kilogram of body weight with the same exercise protocol, the same cycling protocol. And in this case, what the researchers found is that both yohimbine and exercise alone increased fat mobilization about 50 to 100 percent above baseline, respectively.

However, when people combined both exercise and yohimbine the effects were additive. Fat mobilization increased to over 150 percent, which was obviously a very significant effect. 

[00:29:16] Yohimbine is even cooler than that too, because its fat-burning effects go further. It can actually help your body better tap into and burn stubborn fat stores. And it accomplishes this by attaching itself and more or less deactivating the alpha receptors on fat cells, which we recall are the ones that gobble up catecholamines and shut down fat mobilization.

[00:29:46] So then what happens is: when enough alpha receptors are out of commission due to, in this case yohimbine, it’s easier for the catecholamines in your blood to then bind to beta receptors on those fat cells instead of the alpha receptors, which then of course stimulates the fat loss.

So in other words, what yohimbine does is it prevents your fat cells alpha receptors from preventing fat mobilization, from preventing fat loss.

[00:30:14] Furthermore, remember which fat deposits are generally highest in alpha receptors? That’s right, it’s the hard to lose bits that we want to eliminate most, which is why yohimbine is considered particularly effective for burning away those stubborn fat holdouts.

[00:30:35] Now I use “considered” there advisedly because while conclusive studies on yohimbine and stubborn fat, in particular, have not been done yet, at least to my knowledge, we do have very strong indirect evidence for our case. So for example, a study that was conducted by scientists at the Institute of Sports Medicine in Serbia separated 20 elite-level soccer players into two groups.

The first group consumed about 20 milligrams worth of yohimbine pills every day, so it’s about 0.25 milligrams per kilogram of body weight per day, and the second group consumed an equal number of placebo pills that looked identical to the yohimbine.

The scientists had both groups follow their normal soccer training and a new strength training plan. And after three weeks, the yohimbine group had lost five pounds of fat, whereas the placebo group had not lost any.

[00:31:39] Now that’s impressive, but here’s the kicker: these athletes started around 9 percent body fat, very lean, which means that much of the fat that they had left to lose was the stubborn stuff in their lower torsos.

Therefore, it is fair to say that a fair amount of the rather large amount of fat that they lost was assuredly stubborn belly fat, because it is very unlikely that any of those guys had pounds of intramuscular fat stores left to burn.

[00:32:16] Now, all this is why I believe that yohimbine makes fasted cardio more effective than fed cardio for the purposes of losing fat and losing stubborn fat in particular.

[00:32:31] Now a counter-argument could be made that as neat as yohimbine is, your body will simply compensate even more by burning even less fat throughout the day, resulting in what we had seen earlier in studies on just fast cardio, which is more or less the same amount of 24 hour fat loss between fasted cardio plus yohimbine and fed cardio.

[00:33:01] And I think that’s a fair argument. However, I don’t think it’s the case based on years of experience with my own body and working with tens of thousands of people at this point, virtually through people who have read my books and read my articles as my podcasts and so forth and reached out via email, I am fairly convinced at this point that yohimbine and fasted training does indeed speed up fat loss and stubborn fat loss in a meaningful way.

[00:33:30] Okay, so the next supplement that I mentioned was synephrine. And this is a naturally occurring substance that is particularly abundant in the bitter orange fruit and that’s why it’s often referred to by that name. Chemically speaking, synephrine is similar to ephedrine and pseudoephedrine, which are found in many of the over-the-counter cold/allergy medications, which many people take when they’re cutting for the ephedrine and pseudoephedrine.

So accordingly, synephrine then, what it does, is it impacts the central nervous system and it increases basal metabolic rate, which accounts for up to about 70 percent of your daily calorie expenditure. So even relatively moderate increases to BMR can add up to significant additional fat loss over time.

And synephrine also increases the thermic effect of food, which is the energy cost of digesting and processing the food that you eat. And furthermore, there is also evidence that synephrine blocks the alpha receptors on fat cells much like yohimbine, which means that it too can speed up stubborn fat loss. Which is also why I particularly like to combine it with fasted cardio. And as far as stimulants goes, it’s pretty mild. It’s definitely more mild than caffeine.

[00:36:28] Okay, so now let’s talk about types of fasted cardio – which type of fasted cardio is best? Well, if you are familiar with my work, you know that when it comes to cardio and fat loss and maximizing fat loss, I am a big fan of high-intensity interval training.

A number of studies have really at this point conclusively proven that shorter sessions of high-intensity cardio do result in greater fat loss over time than lower longer intensity cardio.

[00:37:02] In fact, one study conducted by the University of Western Ontario found that doing just four to six 30 second sprints burned more fat over time than 60 minutes of inclined treadmill walking, which is one of the staples of bodybuilding cardio, right?

[00:37:20] Furthermore, HIIT, as it’s often referred to, allows you to keep your cardio sessions shorter. And research shows that this helps preserve muscle and strength, which really is our goal, right? Just as much as fat loss when we’re cutting. We want to lose fat, not muscle.

And that point is especially relevant to fasted cardio because research shows that it does accelerate muscle breakdown rates and especially after you finish workout, that’s when it really starts to ramp up. So the longer you train in a fasted state and the longer you wait to eat after, the more muscle you are going to lose, even if it’s just, you know, a small amount at a time. That is what muscle protein breakdown is. You are losing muscle.

[00:38:09] Now, all that said, some people say that HIIT performed in a fasted state is silly because fat oxidation rates are much lower during HIIT exercise. And to that I say, well, yes, it’s true that fat oxidation rates do decline as cardio intensity increases because carbohydrates, stored carbohydrate glycogen, becomes the fuel of choice, there’s a bit more to consider.

[00:38:39] One thing is that research has shown that as you continue to perform regular high-intensity interval cardio sessions, your muscles learn to use less glycogen, less carbohydrate, during your workouts. And then of course fat oxidation rates increase as this adaptation occurs and your muscles get better at oxidizing fats.

And that latter point the fat oxidation in the muscles is particularly relevant to fasted cardio because over time HIIT increases the total amount of fatty acids that your body is able to metabolize during your workouts.

[00:39:21] Another thing to consider is that research has shown that the post-exercise “afterburn effect” as it’s called, is greater with HIIT than with low-intensity steady-state cardio – about double actually, 13 percent versus 7 percent according to one study.

Now, the actual amount of additional calories burned due to this increase in afterburn effect will probably never be more than maybe 50 to 80 calories, but depending on how much cardio you’re doing and how long your cut is, that can add up to something over time.

[00:39:58] Yet another thing to consider is that studies show that HIIT is particularly good for getting rid of stubborn belly fat, including dangerous accumulations of visceral fat, which not only can ruin your aesthetics but also can ruin your health.

[00:40:17] So given all of those points, I think it’s a no brainer to choose HIIT over low-intensity steady-state cardio when you are cutting and you want to maximize your fat loss. And some people say that doing that puts too much strain on your body and it’s going to cause overtraining.

However, I’ve yet to run into that problem with my own body or with the thousands of people that I’ve worked with so long as you don’t go overboard. So, for example, I recommend no more than an hour and a half, maybe two hours of HIIT per week when cutting. Hopefully, you are also doing some resistance training.

I’m assuming that with my recommendation and that you keep your HIIT sessions relatively short, 20 to 25 minutes, no more than 30 minutes. And if you do that, then you know you’re doing with your diet – you’re not starving yourself, your calories aren’t, you know, below BMR or something like that, and you’re also not overdoing it in your resistance training workouts – you can significantly increase your fat loss without running into any symptoms that might have to do with overtraining.

[00:41:19] Now, I do want to quickly mention, though, if you can’t do HIIT or you don’t want to forward ever reason, however, you do want to do cardio to lose fat faster, I recommend that you walk – go to the other end of the intensity spectrum.

And if you want to find out why head over to muscleforlife.com and search for “easiest cardio” and you’ll find an article that I wrote titled something like, “The Easiest Cardio You Can Do to Lose Fat Faster” or something like that. It’s all about walking.

And check out that article and you might be surprised at how much walking can help, just adding some walking to your routine. You have to walk a bit, of course. You can’t just walk 30, 60 minutes a week and expect much. But if you can dedicate a bit of time to walking each week, it can definitely help.

[00:42:05] Okay, so what about fasted weightlifting? That’s something I often get asked about. Well, the good news is: weightlifting causes a dramatic spike in catecholamines levels in the blood and as these chemicals are better able to mobilize fat when you are in a fasted state, fasted weightlifting can be beneficial.

[00:42:26] So I myself, I do all of my exercises, both weightlifting and cardio in a fasted state when I am cutting. And as I said earlier, I’ve found that stubborn fat, in particular, disappears noticeably faster than when I do all of my training in a fed state. And that’s probably, again, mostly because I can’t get those benefits from yohimbine and synephrine.

[00:42:53] A caveat, though, with fasting weightlifting: do not be surprised if you give it a try and you are immediately and dramatically weaker during your first couple of weeks of switching from fed workouts to fasted workouts. You are probably going to lose reps on your big lifts, you might lose reps across the board.

However, you should know this is not because you are losing muscle. It is simply because eating a significant amount of food and carbs in particular before you workout dramatically improves your performance in the gym. If you take the food away, take the carbs away, you lose that boost.

Furthermore, research shows that men, in particular, tend to be quite a bit stronger in the afternoon than the morning, and that’s mostly for hormonal reasons. Testosterone levels are generally higher in the afternoon than in the morning and that can make a difference.

And there are a few other things I’ve written about, it’s on Muscle For Life and I think it’s called, “Can Your Workout Schedule Help You Build Muscle” – not the best title, but I think that’s what it’s called. So search that if you want to read more about how workout timing can affect your workout performance.

[00:44:07] Anyway, getting back on topic here with the fasted training point I had mentioned earlier in this podcast, that your body and your muscles do slowly adapt to training in a fasted state and they learn to preserve carbohydrate, preserve glycogen during training and rely more on fat stores and that then helps your performance come back up to what you’re used to.

[00:44:30] Some people do find though, that it never quite is the same. Working out later in the day after having eaten a fair amount of food vs. getting in there first thing in the morning, sometimes they don’t even feel fully alive yet by the time they’re starting their workouts.

But having gone through it myself many times and having worked with many people – in most cases, you do just get used to it. And while your lifts may never be quite as good as they could be if you were to train at another time with food, that’s not even a major concern when you’re cutting, right?

Because unless you’re new, you’re not really going to be gaining much in the way of muscle and strength. And you really are just trying to lose as much fat as you can as quickly as you can, so you can get back to maintaining or lean bulking or whatever is next for you.

[00:45:24] Okay, so now let’s talk about exactly what you should do if you want to maximize the effectiveness of any fasted training that you might do.

[00:45:35] So if you are going to train fasted, I think you should seriously consider the following two strategies so you can get as much fat loss and as much stubborn fat loss out of it as possible and negate it’s one big downside, which is muscle breakdown.

[00:45:52] So the two strategies are: take the right supplements and eat a post-workout meal. Pretty simple. So let’s go over each supplement first and then we’ll talk about eating.

[00:46:03] So obviously I mentioned two supplements already, yohimbine and synephrine, but there are actually five before my fasted workouts when I’m cutting, and they are: yohimbine, beta hydroxy beta methylbutyrate (HMB), caffeine, and synephrine. So let’s talk about each of them in that order.

[00:46:23] So yohimbine you’ve already learned about. It boosts your metabolism, it boosts stubborn fat loss when taken before fasted training. And in terms of dosages, research has shown that 0.2 milligrams per kilogram of body weight is sufficient for fat loss purposes and that taking it 15 to 30 minutes before exercise is particularly effective for boosting fat loss.

[00:46:48] Now, some people do not do well with yohimbine, some people get very jittery from it. So I always recommend that you start with half that, 0.1 milligrams per kilogram of body weight for your workouts to assess your tolerance.

And if you take that amount and you feel fine, then increase it to the clinically effective dosage of 0.2 milligrams per kilogram of body weight. To further increase fat mobilization during your fasting cardio, you can also combine yohimbine with caffeine and synephrine, which is why they’re on the list and which you will learn more about in a moment.

[00:47:27] Some people also don’t feel good when lifting weights after taking yohimbine. Sometimes it gives them a bit of a queasy stomach. And if that’s the case with you, I would recommend that you only take it before your cardio. So it doesn’t cut too much into the quality of your resistance training workouts.

[00:47:47] You should also know that yohimbine can raise blood pressure. So if you have high blood pressure, I do not recommend that you use it.

[00:47:55] And last is what type of supplement should you take? You can buy yohimbine by itself, but you can also find a clinically effective dosage in it in my pre-workout fat burner Forge, which you can learn about at legionathletics.com/forge.

[00:48:14] All righty, next on the list is beta hydroxy beta methylbutyrate, HMB. So there is a downside to fasted training that I have mentioned a few times, which is that muscle breakdown rates are dramatically increased by it and again, especially after the workout.

Now, this is bad simply because too much muscle breakdown impairs your total muscle growth over time. That really is all muscle growth boils down to mechanically speaking is muscle protein synthesis rates exceeding muscle protein breakdown rates over time. Now what does that have to do with HMB?

[00:48:55] Well, first, let’s talk about what HMB is. It is a substance that is formed when your body metabolizes the amino acid leucine, which is an amino acid that directly stimulates protein synthesis in the body. And of course, that is the primary muscle-building trigger that protein contains – leucine.

[00:49:18] Now, HMB is often sold as a muscle-building aid. One of the more recent supplements I’ve seen was things called clear and that’s all it really was, was HMB. And if you believed the hype, this stuff is as good as steroids. And no.

The research that purports to demonstrate these amazing muscle-building benefits is dubious at best, hindered most by design flaws. So I’m not comfortable making any claims about HMB and muscle growth.

[00:49:57] There is one benefit, however, that is fairly well established in the literature. It does appear to be an effective anti-catabolic agent. In other words, HMB is very good at mitigating muscle breakdown, which means that you may be able to recover a bit faster from your workouts and experience less muscle soreness. There is some evidence of that.

[00:50:23] And another cool thing about HMB is it has no effect whatsoever on insulin levels, which means that it will not break your fasted state and render yohimbine less effective. Making HMB be perfect for use with fasted training and these other supplements.

It has powerful anti-catabolic effects and non-existent insulin effects, which means that you get to reap all of the fat lost benefits of training fasted with a few of these supplements without having to worry about problems related to muscle loss or insulin secretion.

[00:51:00] I think it’s also worth noting that HMB is superior to leucine in suppressing muscle protein breakdown because research shows it’s even more anti-catabolic than its parent amino acid leucine. And what this means then is that for our purposes here, fasted training HMB is more effective than BCAA supplements because those supplements rely on leucine for their anti-catabolic effects, which raises insulin levels, for one; and it also comes with isoleucine and valine, the two other amino acids in BCAA’s, and those are very weak in this regard. Really, all you’re going for is the leucine in the BCAA’s. 

[00:51:41] Now as far as supplementing with HMB, again like yohimbine, you can’t just buy it as a standalone supplement, but you can also find it in the pre-workout fat burner that I mentioned, Forge. So it contains yohimbine, as well as HMB, as well as CDP choline, which is another ingredient that you can learn more about over at legionathletics.com/forge.

[00:52:02] Okay, moving on the list. We have caffeine as the next supplement that I recommend and I personally use when cutting. I take it before my fasted workouts. Now, as you know, weight loss and fat loss really just boils down to energy consumed versus energy expended.

And caffeine helps by increasing your body’s daily energy expenditure, by increasing your metabolic rate. However, it also improves strength and improves muscle endurance and improves anaerobic performance, which is particularly relevant to us weightlifters.

And it also can help reverse the morning weakness that many of us lifters have experienced and that many of us lifters who have switched from afternoon or evening workouts, fed workouts to first thing in the morning fasted workouts.

[00:52:52] Now part of maximizing the fat loss benefits of caffeine is preventing your body from building up too much of a tolerance which can build fairly quickly. Just a week or two of regular use is generally enough to eliminate its stimulatory benefits, its fat loss effects.

It will always be able to block tiredness, but unfortunately our bodies adapt very quickly to its stimulatory effects. So to prevent that and to keep it maximally effective for fat loss, I recommend that before your training you supplement with 3 to 6 milligrams of caffeine per kilogram of body weight.

And if you’re not sure of your caffeine sensitivity, start with 3 and then work up from there. I recommend that you keep your daily caffeine intake at or below 6 milligrams per kilogram of body weight. Do not have your 6 milligrams per kilogram before your training and then drink a couple of coffees throughout the day.

And I also recommend that you do one or two low caffeine days per week, and one or two no caffeine days per week. So a low day should be half of your normal intake. And a no day means less than 50 milligrams. You can have a cup or two of tea, but no coffee, no caffeine pills or pre-workout or anything like that.

[00:54:10] As far as how to get your caffeine, of course, there are many ways to do it, I personally get caffeine from my pre-workout Pulse, which contains a dehydrated and concentrated form of caffeine called caffeine anhydrous. That works very quickly in the body, which is nice.

And you can learn about that at legionathletics.com/pulse. And I don’t have Pulse every day, I’ll take it usually – well, when I’m cutting I guess I do increase my caffeine intake a bit when I’m cutting, so I then drop the coffee out, really. Now, right now I’m maintaining.

For example, so I’ll have some Pulse before my heavy squat and deadlift days usually. Otherwise I don’t have any caffeine before my workouts. I’ll have a cappuccino after. So I keep my caffeine intake pretty low generally. And then when I’m cutting, I’ll drop the coffee out and save all of my caffeine for before my workouts.

[00:55:07] Alrighty, moving on to synephrine. So synephrine, we’ve already talked about, it’s an effective natural fat burner that can help you lose fat and stubborn fat faster.

And rather interestingly, there is research that shows that it’s fat loss effects are amplified when it’s taken with two other molecules that occur naturally in the bitter orange fruit, and those are naringin and hesperidin.

[00:55:34] Now naringin stimulates the production of a hormone called adiponectin, which is involved in the breakdown of fat cells. And it also activates a type of receptor in fat cells that regulate fat mobilization. It’s called the PPARA receptor.

Now, through those mechanisms, naringin also works synergistically with synephrine and hesperidin to further accelerate your basal metabolic rate. That’s really what you get out of it. And so has hesperidin is the other partner of this duo. And it also stimulates the production of adiponectin and activates that same PPRA receptor.

And as a nice little bonus, research shows that hesperidin also improves blood flow and reduces inflammation in blood vessels. And for all of those reasons, I have included clinically effective dosages of synephrine, naringin, and hesperidin in my natural fat burner called Phoenix.

Phoenix also is caffeine-free, which is pretty neat. That is unique in the fat burner space and it’s also quite a bit different than Forge and it’s actually made to be stacked with Forge. And if you want to learn about it, you can just head over to legionathletics.com/phoenix.

[00:56:56] Okay, so now let’s talk about how to use these supplements properly.

[00:57:01] So here is what I do. I take before my fasted training sessions, which when I’m cutting you [00:57:09] wanted to [00:57:09] a day depending on the day, I take 2 servings of Forge, which is the full clinically effective dosage of yohimbine for me.

I take one serving of Pulse, that’s all my caffeine for the day, and one serving of Phoenix. And I should note that Phoenix contains green tea extract, which in some people can make them nauseous, especially on an empty stomach. And if this happens to you, then take it later with food and you’ll be fine.

[00:57:38] Now when I’m cutting, I lift weights in a fasted state five days per week, and I also do 25 to 30 minutes of HIIT cardio in a fasted state three to four times per week. As I’ve mentioned earlier, though, I do go one or two low, and one or two no caffeine days per week when I’m cutting.

Which practically speaking means half of a serving of Pulse, that’s a low caffeine day. And I save my no caffeine days for days where I’m either doing no exercise, which should be one day a week when I’m cutting or just doing cardio – usually my weekends.

I’m lifting Monday through Friday and then usually Saturday is no vigorous physical activity whatsoever. Might do some walking, but no HIIT, no lifting, and then I’ll do some HIIT on Sunday, but no lifting.

[00:58:26] Okay, so now let’s talk about eating after fasted exercise. That was one of the two strategies for maximizing its effectiveness. And people often ask me what they are supposed to eat after fasted cardio and my answer is this: eat the same thing that you would eat after any workout, which should be about 30 to 40 grams of protein and the same amount of carbs.

That’s a good rule of thumb. You can adjust those numbers based on your target calories and your macros, but that’s a good starting place for most people. Research also shows that it is probably best to eat your post-workout meal within about 30 minutes of finishing your workout, your fasted workout, because as I’ve mentioned several times, muscle protein break down rates really start to ramp up so you can prevent that by eating protein.

[00:59:21] Now, some people would disagree with that advice. They would say that you should wait longer before eating after a fasted workout to really prolong those fat-burning effects and especially if you’re taking supplements. I think this is unnecessary.

I think it’s counterproductive for two reasons. One is: it’s not going to help you lose more body fat. So if you assume that your total calorie intake for the day is the same, you are going to lose the same amount of body fat, whether you have a meal right after or several hours after your workouts.

The reason for this is with or without supplements, research shows that the increase in stubborn fat burning that occurs during fasted training, it disappears fairly quickly once you stop working out. So in other words, most of the fat-burning benefits of fast and training, especially when combined with the right supplements occurred during the exercise, not afterward, which makes prolonging the fast unnecessary. 

[01:00:21] Another reason why I don’t like to prolong the fast after fasted training is it will probably result in muscle loss. Now it’s not going to be a dramatic amount, you’re going to see in the mirror. But muscle protein breakdown rates do drastically ramp up and increase after both resistance training and cardio workouts. It’s not just a cardio thing, it’s also a weight lifting thing.

[01:00:43] What many people don’t realize is exercise is really a catabolic activity. Muscle building occurs after the workouts. Research shows that muscle protein synthesis and breakdown rates tend to increase while you’re working out. And then when you finish your workout, synthesis rates plummet, and break down rates skyrocket.

So when you look at it on the whole, working out is a catabolic activity. And as I mentioned, this problem is only aggravated by fasted training, which increases those break down rates even further. And then just to add insult to injury, most people, of course, are using fasted training when they are cutting, which also makes you more susceptible to muscle loss.

So by delaying your post-workout meal after your fasted training, you’re really just setting yourself up for maximum post-workout muscle loss. Now, one of the most effective ways to decrease muscle protein break down after a workout, whether it’s a fasted workout or a fed workout, is to raise insulin levels.

And one of the best ways to do that, of course, is to eat a protein and carbohydrate-rich meal. And if you eat protein in that meal, you also are going to be providing your body with leucine, which as I’ve mentioned, triggers muscle protein synthesis. It ramps up muscle protein synthesis rates.

[01:02:08] So let’s summarize here. The bottom line is that by itself, fasted cardio is not going to help you lose more fat than fed cardio over time. It’s not going to make much of a difference. However, when you combine it with the right supplements, it becomes a valuable fat loss strategy that I do think you should consider trying.

And this is especially true if you are lean and you want to get really lean because you are going to be dealing mainly with stubborn fat stores that can be very slow to disappear with just diet exercise alone.

[01:02:45] Now, in terms of what kind of cardio you should do when you’re doing your fasted cardio, I recommend that you stick with HIIT if you can, which is going to give you the most fat-burning bang for your buck, so to speak. And if you cannot do HIIT or you don’t want to, go with walking.

Again, head over to Muscle For Life and search for “easiest cardio“, check out that article I wrote on it. When you’re cutting, you can also do your weight lifting workouts, your resistance training in a fasted state to accelerate fat loss and stubborn fat loss even further.

If you do this, you probably will notice a slight drop in your strength when you start lifting in a fasted state, but it should also probably come back fairly quickly within a few weeks as your body re-acclimated to not having a bunch of carbohydrates available.

I also recommend that you have a post-workout meal within about 30 minutes of your fasted workouts to minimize muscle loss and have some protein and carbs in those meals. 

[01:03:44] When I’m dieting for fat loss, what I do is I lift weights in a fasted state five days per week and then I do a few sessions of 25 to 30 of HIIT cardio in a fasted state. In terms of schedule, what I do is I lift first thing in the morning and then I do my cardio after work at 6 or 7.

And although I haven’t cut in months now, I’ve been maintaining for a long time, I can have caffeine at 6 or 7 and not have it interrupt my sleep. At least that was the case the last time I cut. I guess we’ll see if that’s still the case the next time I cut.

[01:04:22] Now, if that doesn’t work for you and I understand it doesn’t work for a lot of people, you can leave the caffeine out of the HIIT cardio. If you want to follow the general advice is: cut your caffeine intake six to eight hours before you go to bed, no more caffeine.

And what you can do then is just have yohimbine and synephrine before your cardio if you are doing it within 68 hours of your bedtime. You will still get fat-burning benefits, significant fat-burning benefits, and those supplements are processed much quicker by the body. They don’t linger as long as caffeine does.

[01:04:58] Now, in terms of supplements, before my fasted workouts, I generally will take two servings of Forge to get a good clinically effective dosage of yohimbine as well as HMB and CDP choline, which I didn’t talk about here, but you can read about if you want to learn about Forge.

Also, I’ll get my caffeine from Pulse, my pre-workout supplement and I will take a serving of Phoenix to get synephrine. And then after my workout I have a post-workout meal that contains at least 40-ish grams of protein and about the same amount of carbs, sometimes more depending on what I’m doing with my meal plan.

[01:05:31] And that’s it. That’s the whole shebang. I know this is a bit of a longer episode, but I want it to be very thorough, so I hope you have enjoyed it.

What did you think of this episode? Have anything else to share? Let me know in the comments below!

+ Scientific References

Readers' Ratings

5/5 (1)

Your Rating?