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Does caffeine boost your performance even if you’re a habitual coffee drinker? How does strength training influence fat burning? Can eating vegetables boost your recovery? How does the carnivore diet affect health markers? Will having a spotter boost your bench press? This is what the latest research says about these questions.

This podcast is part of a new series I’m going to call Research Roundups. What is it going to be? Well, there is a ton of scientific research that gets published every year, and even if you narrow your focus to fitness research, it would still take several lifetimes to unravel the hairball of studies on nutrition, training, supplementation, and related fields. 

That’s why my team and I put a lot of time into reviewing, dissecting, and describing scientific studies in articles, podcasts, and books. And while the principles of proper eating and exercising are relatively simple and fairly immutable at this point, new research can help us understand why the fundamentals work. They can help us understand how to better implement them, and how to get better results with them.

And occasionally every so often there are new and better methods of eating, exercising, supplementing, and living to achieve our health and fitness goals faster. And so in this series of episodes, you’re going to learn about new research on various things related to building muscle, losing fat, getting healthy, improving wellbeing, and so on. 

In today’s episode, I’m going to be talking about how lifting weights affects gene expression, whether caffeine boosts performance if you’re a regular coffee drinker, the health effects of the carnivore diet, and more. So listen if you want to learn the answers to those questions and more. 

Oh and if you like this type of episode, let me know. Send me an email ([email protected]) or direct message me on Instagram (@muscleforlifefitness). And if you don’t like it, let me know that too or how you think it could be better.


0:00 – My award-winning fitness books for men and women:

3:56 – How does strength training burn fat and help you lose weight?

6:42 – Can eating cruciferous vegetables improve your muscle recovery?

9:13 – How does caffeine affect physical performance if you regularly drink coffee?

14:23 – Is the carnivore diet good for you?

18:05 – How can spotting improve bench press performance?

Mentioned on the Show:

My award-winning fitness books for men and women:

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


Hey, hey, and welcome to another episode of muscle for life. I am Mike Matthews. Thank you for joining me today for the second installment in this research roundup series that I wanted to start doing. The response was positive to the first one. And so here I am with the second one and there will be more to follow.

So what will today’s episode be about? Well, I’m going to be breaking down five studies and one is going to be on how weightlifting training. It enhances fat burning at a genetic level. Another is going to be on cruciferous vegetables and muscle recovery after training. The third is going to be on caffeine’s effects on physical performance in habitual coffee drinkers.

So, those of us who are very desensitized to caffeine. And the fourth study is going to be on the carnivore diet and how it can impact our health and lastly, spotting and bench press performance. Can having a spotter boost your bench press performance? Before we get to it. If you like what I’m doing here on the podcast, then you’re going to love my award winning fitness books for men and women, which have sold well over 1 million copies, have received over 15, 000 4 and 5 star reviews on Amazon, and have helped, that I know of, tens of thousands of people build their best body ever.

Because here’s the deal, building lean muscle, losing stubborn fat, and gaining whole body strength isn’t nearly as complicated as you have probably been led to believe. And my books are the shortcut. They give you everything you need to build your best body ever without having to live in the gym, give up all the foods or drinks you love.

Or do long, grueling workouts you hate. So, if you are someone over the age of 40, man or woman, and if you are new to resistance training, or relatively new to resistance training, you want to get my book, Muscle for Life. That is going to be the best one for you, and that is going to be the best program for you.

And if you are a man under the age of 40 trying to gain your first 25 pounds of muscle, then you’ll want Bigger Leaner Stronger. And if you’d also like a workout journal with an entire year’s worth of Bigger Leaner Stronger training that takes you from novice to expert, pick up a copy of the Year One Challenge for men.

as well. And if you’re a woman under the age of 40 trying to gain your first 15 pounds of muscle or lose your first 15 pounds of fat, you can lose more, of course. But if you’re trying to lose that first 15 pounds, then my book, thinner, leaner, stronger will show you the way. And I also have a workout journal for you with a year’s worth of thinner, leaner, stronger training called the year one challenge for women.

So you might want to pick up that. to. And finally, if you are an advanced weightlifter with at least three years of proper training under your belt, I have a book and program for you too. It is called beyond bigger, leaner, stronger. And there is a workout journal that goes with it called the beyond bigger, leaner, stronger challenge.

Now, you can find all of my books on all major online retailers, like Audible, Amazon, iTunes, Kobo, Google Play, and there probably are a few others that I’m not thinking of, as well as in select Barnes Noble stores, and I should also mention that you can get any of my audiobooks for free when you sign up for an Audible account, and that’s a great way to make those pockets of downtime, like commuting, meal prepping, cleaning, more interesting, entertaining, and Productive.

And if you want to take audible up on that offer and get one of my audio books for free, just go to buy legion. com slash audible. That is B U Y legion. com slash audible and sign up for your account and get one of my audio books for free. Okay, so let’s start with the first study, which is called mechanical overload induced muscle derived extracellular vesicles promote adipose tissue lipolysis.

A lot of words there, but I’m going to break this down in layman’s terms, so it’s very easy to understand. So most people, they assume that weightlifting helps you lose weight or lose fat because it simply burns calories. And while that is true, True, it’s not great for burning calories. Cardio is better, but of course the calories burned during a weightlifting workout do help or do support weight loss or fat loss.

However, researchers at the university of Nebraska Lincoln found that there is more to the story. So in this study, the scientists had six men and four women aged between 26 and 50 years old, give a blood sample and muscle biopsy from the vastest. Lateralis muscle, which is a quadriceps. It’s one of the quadriceps muscles.

And then the people, they performed four sets of seven reps of the leg extension exercise and leg press exercise with two minute rests between the sets, and then they did a five minute rest between exercises and 30 minutes after the participants had finished their. Training, the researchers took another blood and muscle sample and then analyzed and compared the pre and post workout samples and what they found is weightlifting causes our muscles or resistance training causes our muscles to release a special type of cell into our blood called an extracellular protein.

vesicle. And these special cells, they leave our muscles and then they carry with them strands of genetic material called myr1, M I R hyphen 1, which then they deposit in neighboring fat cells. Now, why is that important? Well, when myr1 is in muscle tissue, it hinders muscle growth, but when it is in fat cells, when it is deposited into fat cells, it speeds up.

fat burning. So in other words, what this study found is that resistance training causes a shift in the expression of certain genes that accelerate muscle growth and fat burning. And so then this is just yet another reason to do regular strength training workouts. And I suspect that over the next 10 to 20 years, researchers are going to find more and more Reasons that they are not currently aware of.

It just seems that about everything in the body just works better when you are doing regular strength training workouts. Okay, let’s move on to eating cruciferous vegetables and how that might impact muscle. recovery. So the study I’m going to discuss here is called oral chronic sulforaphane effects on heavy resistance exercise implications for inflammatory and muscle damage parameters in young practitioners.

Now Let’s Most people, they don’t think of vegetables as muscle building foods, but this study, which came from scientists at Kobe University, suggests that maybe we should because in this experiment, the scientists wanted to see how sulforaphane, which is a compound that’s found in cruciferous vegetables like broccoli, brussels, sprouts and cabbage.

They wanted to see how it affects muscle damage and recovery after training. And so what they did is they tested the bench press one rep max of 10 men, and then they randomly assigned those men to either a sulforaphane supplement group who took 30 milligrams of sulforaphane per day or a placebo group.

And after one month, the participants returned to the lab to retest their bench press with three sets of eight reps. And they also gave blood samples 30 minutes and. 24 hours post exercise, which allowed the researchers to measure levels of two markers of muscle damage and inflammation, creatine kinase and interleukin six.

Now the next leg of the experiment was a switch up a switch of supplementation protocols. So the original sulforaphane group, they started taking the placebo and vice versa another month and then returning yet again to retest. the bench press. And what the results showed is that when the men took sulforaphane supplements instead of the placebo, creatine kinase levels were significantly lower 24 hours post exercise and interleukin 6 levels were significantly lower 30 minutes post exercise.

And so what does that mean? Practically speaking. Well, I wouldn’t recommend that you start replacing your whey protein shakes with broccoli smoothies, but this is a good reminder that building muscle is not all about just eating enough calories and eating enough protein. Those are. Probably the 20 percent that gives you the 80%.

Those are the most important nutritional factors, but other stuff matters to fruits and vegetables. For example, they can support your recovery and gaining muscle is what happens outside of the gym. When your body is recovering, remember that. Okay, let’s talk about caffeine now and physical performance.

Let’s review a study called dispelling the myth that habitual caffeine consumption influences the performance response to acute caffeine supplementation. So if you are a regular caffeine user, you know that it’s most invigorating. It’s most exciting effects. They don’t last long. They wane after just a couple of weeks of regular use.

But does that mean that having caffeine before a workout? Is ineffective. Does that mean that it’s less effective if you have caffeine regularly? Well, that’s what scientists at the University of Sao Paulo wanted to ascertain when they studied 40 male cyclists who they split into groups depending on their habitual caffeine.

Consumption. And so you had some guys at low consumption, 2 to 101 milligrams per day, moderate consumption, 104 to 183 milligrams per day, and then high 190 to 583 migs per day. And just for reference, a typical six ounce cup 70. Milligrams of caffeine, but that can vary based on the beans and how you’re preparing the drink.

But for the study, the cyclists, what they did is they performed three cycling time trials an hour after consuming six milligrams per kilogram of body weight of caffeine, a placebo, or Nothing. And for reference, that’s about one full serving of my pre workout pulse for most people, which has 350 milligrams per full serving.

And so the results showed that supplementing with caffeine increased the cyclist’s performance to a similar degree, regardless of how much coffee they regularly drink. In other words, the study showed that the performance boost from caffeine did not depend on how habituated the person was to caffeine.

Now, the findings of this study are contrary to previous research, which found that caffeine does improve physical performance. But if you habitually consume caffeine, if you habitually drink coffee, for example, the effects are going to be a lot smaller or can disappear altogether. But what’s different about the study that I just shared with you and the couple of other studies that I’m referring to is in the previous studies, you had regular coffee drinkers who were given an amount of caffeine that they were used to drinking.

But in this study, all of the participants in the low and moderate groups and some or even most of the participants in the high group were given. Larger caffeine doses than they were used to having. So, judging by the results of this study and the weight of the evidence overall, it appears that coffees and caffeines performance enhancing effects are not tempered much, at least by regular consumption, provided that you have more than you’re used to on training days.

And so if you want to put this information into immediate use, what you can do is you can cycle your caffeine intake. You can have a few low days per week, maybe no more than a hundred max, 200 milligrams, maybe even none. If you don’t drink coffee, for example, and you can just leave out the pre workout or maybe switch to a stim free pre workout on those days.

And then you have a couple of high days, which might be in the range of three to 400, maybe even 500 milligrams, depending on how much you weigh. And maybe those days are going to be your heaviest, hardest workouts, your squat workout, your deadlift workout, your press workout. So maybe three days per week, you are having a larger dose 30 to 45 minutes before those training sessions.

And then you have one or two days where you could have a low amount, no amount, a moderate amount, but not a high amount. Save the large doses for those few most difficult. Workouts and if you use my pre workout pulse, what you can do if you are so inclined is you can get a bottle of the stim free, which is caffeine free to go with your caffeinated pulse.

And so what many of my customers do is they make sure that they are getting a full serving of pulse at least five days per week to benefit from. Not just the caffeine and theanine, but the other ingredients in it, like beta alanine, for example, you want to be taking it fairly regularly to get its benefits.

And so to make sure that they are getting, let’s say five servings of pulse per week, they will on some days Just have a full serving of the stem free on other days. They’ll do like one scoop. So a half of a serving of the caffeinated, which is 175 megs of caffeine. And then they’ll do a half of a serving of the stem free.

So they get a full serving of the beta alanine and citrulline and BTE and alpha GPC with a half serving of the caffeine and theanine. Okay, let’s move along to the carnivore diet. More evidence that it is not great for your health. So this is a study called behavioral characteristics and self reported health status among 2000 and 29 adults consuming a carnivore.

Diet. Now, more and more people have been trying this diet because of social media and many of the supposed health benefits and body composition benefits, despite the fact that many of the claims that are made about this diet are still completely theoretical or unproven. Thankfully, recent research conducted by scientists at Boston Children’s Hospital gives us some empirical evidence about how eating only meat affects your health.

So in this study, the researchers conducted a social media survey of 2029 participants who had been following a carnivore diet for an average of 14 months. Mostly for health reasons, 93 percent of them reported this and the vast majority of these people, 95 percent of them, they were satisfied with their diet and they felt that their health and their body composition had benefited from avoiding plant foods.

But the health markers… Tell another story. The most concerning results were the participants LDL cholesterol and coronary artery calcium levels. Now, in case you are not familiar with coronary artery calcium levels, that is a measurement of the amount of calcium that is deposited in your blood vessels, and that’s a marker of plaque buildup.

So we’re looking at atherosclerosis there, which of course increases your risk of heart disease. The results in this study, what they showed, is that the participants average pre diet LDL level was 139, while the average post diet LDL level was 169. So what that means is, on average, these people, their levels, LDL, cholesterol, they went from being considered borderline high to high.

In 14 months since they had started the carnivore diet and what’s worse is their coronary artery calcium levels had increased from 183 to 322, which means that the risk of all cause mortality and heart disease increased significantly since they removed plant foods from their diet. And unsurprisingly, by the way, one of the best ways to decrease.

Coronary artery calcium levels is to just eat plants, eat more fruits and vegetables. That is the overwhelming weight of the evidence. Now, carnivore enthusiasts will be quick to point out that this study should be taken with a whole lick of salt because it was a social media survey and only 15 of the participants provided details about their health biomarkers.

But to that, I would say, look, it does not inspire confidence. Right. And as heart disease is the number one killer in the world, we should take special care to preserve our tickers. And again, if we want to just play it safe and go with the overwhelming weight of the scientific evidence, one of the best ways to do that.

Is to eat more plant foods, not less. You don’t have to follow a vegan or vegetarian diet, but a lot of your daily calories should be coming from fruits and vegetables and whole grains and seeds and legumes and so forth. Okay, the final study I want to share with you on this episode is about spotting and how it can affect bench press performance.

So, this comes from a paper called Presence of Spotters Improves Bench Press Performance, a Deception Study. So, most of us will ask for a spot on the bench press for safety, but in this study, It was found that it can boost performance. So what the researchers did is they had 12 recreationally trained men in their early twenties, complete two workouts, consisting of three sets of the Smith machine bench press with 60 percent of their one rep max to failure.

And in one of the sessions, the lifters could see that they had two spotters, but in the other session, the spotters hid silently behind opaque shielding. And so what the researchers did is they told the lifters, the participants, that the barriers were in place to see if the people would perform better with no distractions.

But the participants did not know that spotters were standing by should they drop the weight. And on average, the participants could do an additional one and a half reps when they knew they had a spotter. What’s more, participants reported feeling more confident that they would be able to do the same number of reps or more in subsequent sets when they had a visible spotter.

And if you are scoffing because what’s an extra one and a half reps per set, it’s not. Much, but if you do, let’s say six to nine sets of pressing in a chest or a push workout, that could add up to as many as 13 extra reps for that workout. And that actually could have a slight but significant effect on the amount of muscle that you gain over time from those workouts because of the extra.

Volume. So if you have somebody who can spot you on the bench press, uh, it’s a good idea for the purposes of safety, but you also will probably perform better. Well, I hope you liked this episode. I hope you found it helpful. And if you did subscribe to the show, because. it makes sure that you don’t miss new episodes and it also helps me because it increases the rankings of the show a little bit which of course then makes it a little bit more easily found by other people who may like it just as much as you and if you didn’t like something about this episode or about the show in general or if you have Uh, ideas or suggestions or just feedback to share, shoot me an email Mike at muscleforlife. com and let me know what I could do better or just, uh, what your thoughts are about maybe what you’d like to see me do in the future. I read everything myself. I’m always looking for new ideas and constructive feedback. So thanks again for listening to this episode and I hope to hear from you soon.

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