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Andrew Huberman (00:00):

Welcome to the Huberman Lab Podcast, where we discuss science and science-based tools for everyday life. I’m Andrew Huberman, and I’m a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, I have the pleasure of introducing Dr. Duncan French as my guest on the Huberman Lab Podcast. Dr. French is the Vice President of Performance at the UFC Performance Institute, and he has over 20 years of experience working with elite professional and Olympic athletes. Prior to joining the UFC, French was the Director of Performance Science at the University of Notre Dame.


And he has many, many quality peer-reviewed studies to his name, exploring, for instance, how the particular order of exercise, whether or not one performs endurance exercise prior to resistance training or vice versa, how that impacts performance of various movements and endurance training protocols, as well as the impact on hormones, such as testosterone, estrogen, and some of the stress hormones, such as cortisol. He’s also done fascinating work exploring how neurotransmitters, things like dopamine and epinephrine, also called adrenaline, can impact hormones, and how hormones can impact neurotransmitter release.


What’s particularly unique about Dr. French’s work is that he’s figured out specific training protocols that can maximize, for instance, testosterone output or reduce stress hormone output in order to maximize the effects of training in the short term and in the long term. So today you’re going to learn a lot of protocols, whether or not you’re into resistance training or endurance training. You will learn, for instance, how to regulate the duration of your training and the type of training that you do in order to get the maximum benefit from that training over time.


So whether or not you are somebody who just exercises recreationally for your health, whether or not you’re an amateur or professional athlete, or whether or not you’re just trying to maximize your health through the use of endurance and or resistance training, today’s discussion will have a wealth of takeaways for you. There are only a handful of people working at the intersection of elite performance, mechanistic science, and that can do so in a way that leads to direct, immediately applicable protocols that anybody can benefit from. Dr. French also provides some incredibly important insights about the direction that sport and exercise are taking in the world today and their applications towards performance and health.


Before we begin, I’d like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of my desire and effort to bring zero cost to consumer information about science and science-related tools to the general public. In keeping with that theme, I’d like to thank the sponsors of today’s podcast. Our first sponsor is Athletic Greens. Athletic Greens is an all-in-one vitamin mineral probiotic drink.


Been taking Athletic Greens since 2012, so I’m delighted that they’re sponsoring the podcast. The reason I started taking Athletic Greens and the reason I still take Athletic Greens once or twice a day is that it helps me cover all of my basic nutritional needs. It makes up for any deficiencies that I might have. In addition, it has probiotics, which are vital for microbiome health. I’ve done a couple of episodes now on the so-called gut microbiome and the ways in which the microbiome interacts with your immune system, with your brain to regulate mood, and essentially with every biological system relevant to health throughout your brain and body.


With Athletic Greens, I get the vitamins I need, the minerals I need, and the probiotics to support my microbiome. If you’d like to try Athletic Greens, you can go to slash Huberman and claim a special offer. They’ll give you five free travel packs, plus a year’s supply of vitamin D3K2. Our ton of data now showing that vitamin D3 is essential for various aspects of our brain and body health. Even if we’re getting a lot of sunshine, many of us are still deficient in vitamin D3. And K2 is also important because it regulates things like cardiovascular function, calcium in the body, and so on.


Again, go to slash Huberman to claim the special offer of the five free travel packs and the year supply of vitamin D3K2. Today’s episode is also brought to us by Inside Tracker. Inside Tracker is a personalized nutrition platform that analyzes data from your blood and DNA to help you better understand your body and help you reach your health goals. I am a big fan of getting regular blood work done.


Trying to do it as much as I can afford for years. The reason is that many of the factors that impact our immediate and long-term health can only be discovered from a quality blood test. With most blood tests and DNA tests, however, you get information back, but not a lot of information about what to do with those numbers. With Inside Tracker, they give you a lot of specific recommendations as to lifestyle factors and nutrition factors, supplementation factors, things you may want to add to your life or things you may want to delete from your life in order to bring the numbers into the ranges that are best for your immediate and long-term health.


There’s simply no replacement for these kinds of data and your data are the most important data to you and quality blood tests and DNA tests are the way to access them. If you’d like to try Inside Tracker, go to slash Huberman to get 20% off any of Inside Tracker’s plans. That’s slash Huberman to get 20% off. Today’s episode is also brought to us by Thesis. Thesis makes what are called nootropics, which means smart drugs.


And to be honest, I am not a fan of the term nootropics. I don’t believe in smart drugs in the sense that I don’t believe that there’s any one substance or collection of substances that can make us smarter. I do believe based on science, however, that there are particular neural circuits and brain functions that allow us to be more focused, more alert, access creativity, be more motivated, et cetera. That’s just the way that the brain works, different neural circuits for different brain states. Thesis understands this. And as far as I know, they’re the first nootropics company to create targeted nootropics for specific outcomes. I’ve been using Thesis for more than six months now, and I can confidently say that the nootropics have been a total game changer. My go-to formula is the clarity formula, or sometimes I’ll use their energy formula before training. To get your own personalized nootropic starter kit, go online to slash Huberman, take a three-minute quiz, and Thesis will send you four different formulas to try in your first month. That’s slash Huberman and use the code Huberman at checkout for 10% off your first order. I’m pleased to announce that the Huberman Lab Podcast is now partnered with Momentous Supplements. We often talk about supplements on the Huberman Lab Podcast, and while supplements aren’t necessary for everybody, many people derive tremendous benefit from them for things like enhancing the quality and speed with which you get into sleep, or for enhancing focus, or for hormone support.


The reason we partnered with Momentous Supplements is several fold. First of all, their supplements are of the absolute highest quality. Second of all, they ship internationally, which is important because many of our podcast listeners reside outside the US. Third, many of the supplements that Momentous makes, and most all of the supplements that we partnered with them directly on are single ingredient formulations. This is important for a number of reasons. First of all, if you’re going to create a supplement protocol that’s customized for your needs, you want to be able to figure out which supplement ingredients are most essential and only use those. And supplements that combine lots of ingredients simply won’t allow you to do that.


So in trying to put together a supplement protocol for yourself that’s the most biologically effective and cost effective single ingredient formulations are going to be the most useful. If you’d like to see the supplements that we’ve partnered with Momentous on, you can go to slash Huberman. And there you’ll see many of the supplements that we’ve talked repeatedly about on the Huberman Lab podcast episodes. I should mention that the catalog of supplements that are available at slash Huberman is constantly being expanded. So you can check back there slash Huberman to see what’s currently available. And from time to time, you’ll notice new supplements being added to the inventory. And now my conversation with Dr. Duncan French.


Duncan French, great to see you again.

Duncan French (07:53):

Likewise, likewise. Thank you. I don’t often have many Stanford professors in the Performance Institute, so I’m really excited.

Andrew Huberman (07:59):

Oh, well, this place is amazing and you have a huge role in making it what it is. The reason I’m so excited to talk with you is that you’re one of these rare beasts that you have been involved in human performance and athletic performance at the collegiate level. You are obviously very involved in MMA now and the UFC Performance Institute. And you also had the fortunate experience, I like to think, of doing a PhD in, what exactly was the PhD in?

Duncan French (08:32):

It was exercise physiology.

Andrew Huberman (08:32):

So you’re familiar also with designing studies, control groups, all the sorts of things that, in my opinion anyway, are kind of lacking from the internet social media version of exercise science, which is that people throw out all sorts of ideas about how people should be training, what they should be doing and eating and not eating and doing. And certainly science doesn’t have all the answers, but I just think it’s so rare to find somebody that’s at the convergence of all those different fields. And so I have a lot of questions for you today that I’m sure the audience are going to be really interested in it.

Duncan French (09:06):

Well, listen, I mean, I appreciate that. It’s very humbling and yeah, I’ve worked hard to get to where I am, but I’ve always tried to be authentic. And I think authenticity comes alongside, you know, academic rigor and objectivity and insight and knowledge base, right? At the end of the day, it’s about having confidence, having expertise and being able to deliver that expertise to, in my world, to athletes.


And I think that’s what I’ve always tried to do. I’ve tried to have many strings to my bow so that I can talk with many different hats on. You know, one day I’m talking to a coach, the next day I’m talking to an athlete, the next day I’m talking to a CEO, the next day I’m talking to an academic professor. So I think being able to wear those different hats is certainly a skillset that I’ve tried to build throughout my career. And, you know, like I said, I’ve been blessed to work with, I think it was 36 different professional or Olympic sports last time I counted. So yeah, it’s been a wild ride. It’s been great.

Andrew Huberman (10:05):

Which of those sports was the most unusual?

Duncan French (10:07):

I’ve worked with Crown Green Bowling, which I don’t know, as an American guy, I don’t know how well you know that. I’ve never heard of it. Basically, imagine a 20 foot by 20 foot square of turf with a small raise in the middle, i.e. the crown. So it slopes to the edges. And then, you know, you throw out a white jack, a smaller ball, and then you roll out larger balls to try and get closest to the jack. It’s a very European thing, let’s say. But yeah, sports performance at Crown Green Bowling. There you go.

Andrew Huberman (10:41):

All right, wow. And then to mixed martial arts fighters. Absolutely. And everything in between. So along those lines, could you give us a little bit of your background? You know, where’d you start out? Where are you from originally?

Duncan French (10:54):

Yeah, I’m from the Northeast of England. So I’m from a town called Harrogate, which is in Yorkshire, which is a Northern kind of area of the UK. Nice sunny weather all year long. Yeah, you can imagine, yeah, with the two weeks of summer that we get, you know. But yeah, I mean, I did my undergraduate studies there in sports science. I did teacher training to be a physical education teacher after that. Like most people, I then worked as a high school physical education teacher. You know, great experience working with kids, developing athletic qualities, but something in the back of my mind. Always, you know, I wanted more. I wanted to be at the higher end of elite sport. I was a failed athlete like many people. I represented my country in different sports and things, but I never made it professionally. So, you know, that little seed was sown in as much as I then started to reach out to, you know, to different areas to do a PhD, whether it was in the UK or also, you know, chance my arm took a punt, see if we could get over to the States. All my buddies were going on, you know, gap years after the Finnish university or whatever, and going to Bali and hanging out or whatever, traveling through Thailand, and I figured, well, you know, I’ve always loved the States and can I go and kill two birds with one stone and do something academic, continue my studies, but also do it in a different environment and get some life experience. And then many, many rejections, as I’m sure you’re kind of aware from different professors, whether it was Roger Enoka or, you know, William Cramer. So you just wrote to these folks? I just cold called and sent out information and said, yeah, so have you got any opportunities? Pushed back from them all, but, you know, dogged and kept asking. And yeah, Dr. William Cramer, who was at Ball State University in Indiana at the time, you know, a muscle neuroendocrinologist and researcher in muscle physiology using resistance training, you know, he basically said, listen, I can guarantee your funding for the first year of your studies, but not the next three. Sounds like a typical academic response.

Andrew Huberman (12:51):

I can take care of you, but not that well necessarily.

Duncan French (12:55):

Right, yeah. So I spoke to my parents and said, hey, can we take a punt? And they, you know, they were great in supporting me. And yeah, long story short, came out to begin my PhD at Ball State. After a year, Dr. Cramer transferred to UConn, you know, Connecticut in stores in the Northeast there. And I transferred with him. And yeah, four great years with my PhD and getting my PhD with a really prolific research group that looked at, you know, neuroendocrinology, hormonal work, but using a resistance training primarily as an exercise stressor as a major mechanism and then looking at all the different physiologies off the back of resistance training.

Andrew Huberman (13:33):

Yeah, you guys were enormously productive. I found dozens of papers on how weight training impacts hormones and your name’s on all of them. And it’s remarkable. I have a question about this. I’ll just inject a question about weight training and hormones. You hear this all the time that doing these big heavy compound movements or resistance training increases androgens, things like testosterone, DHT, DHEA, and so forth.


Does anyone know how that actually happens? Like what about, what about, what is it about engaging motor neurons under heavy loads sends a signal to the endocrine system, hey, release testosterone. I’ve never actually been able to find that in a textbook.

Duncan French (14:18):

Yeah, well, I mean.

Andrew Huberman (14:19):

And how can I do more of that?

Duncan French (14:21):

As much as I know, you know, and again, I’m digging out into the annals of Duncan French’s kind of brain now, but yeah, I mean, I think it’s a stress response, right? It’s mechanical stress and it’s metabolic stress. And these are, you know, the downstream regulation of testosterone release at the gonads comes from many different areas. You know, my work primarily looked at, you know, catecholamines and sympathetic arousal. So things like epinephrine, adrenalin. Correct, yeah, epinephrine, adrenalin, you know, noradrenalin, how they were signaling, that signaling cascade using, you know, the HPA axis releasing cortisol, and then, you know, looking at how that also influenced the adrenal medulla to release, you know, androgens, and then signaling that at the gonads.

Andrew Huberman (14:46):

So things like epinephrine, adrenalin. Correct, yeah, epinephrine, adrenalin, you know, noradrenalin, how they were signaling, that signaling cascade using, you know, the HPA axis releasing cortisol, and then, you know, looking at how that also influenced the adrenal medulla to release, you know, androgens, and then signaling that at the gonads. That raises an interesting question. So in, presumably, weight training in women, people who don’t have testes, also it increases testosterone. And is that purely through the adrenals? When women lift weights, their adrenal glands release testosterone.

Duncan French (15:21):

Absolutely, I mean, that is the only area of testosterone release for females. And yes, it’s the same downstream cascade. Obviously, the extent to which it happens is significantly less in females, but that’s how you, there’s good data out there that shows, you know, females can increase their anabolic environment, their internal anabolic milieu, using resistance training as a stressor. And then they get the consequent muscle tissue growth, you know, whether it’s tendon, ligament, adaptations, you know, the beneficial consequences of resistance training which is driven by anabolic stimuli. Yeah.

Andrew Huberman (15:54):

I have two questions about that. The first one is something that you mentioned, which is that the androgens, the testosterone, comes from the adrenals under resistance loads in women. Is the same true in men? I mean, we hear that the testes produce testosterone when we weight train for men that have testes, but do we know whether or not it’s the adrenals or the testes in men that are increasing testosterone? Yeah, I think it’s- More or both, a little bit from each?

Duncan French (16:19):

The field is divided presently. I mean, as much as understanding the acute adrenergic response in terms of anabolic response to exercise in an acute phase and the exposure to a stimulus that is stress-driven, which might be partly from the adrenal glands, partly from the gonads, versus a longitudinal exposure to anabolic environments, which is primarily driven by, obviously, the gonads and the release, the endocrine environment from testosterone release at the gonads. So the field is split in terms of how exercise is promoting hypertrophy, muscle tissue growth, and whether that is very much an adrenal stimuli, or if that’s significant enough in these acute responses versus the longitudinal exposure to just elevated basal levels of anabolic testosterone at a habitual level.

Andrew Huberman (17:15):

So it sounds like with most things it’s probably both. It’s probably the adrenals and the gonads. And then you mentioned that testosterone can have enhancing effects or growth effects on tendon and ligament also. You don’t often hear about that. People always think, you know, testosterone muscle, but testosterone has a lot of effects on other tissues that are important for performance, it sounds like.

Duncan French (17:38):

Yeah, yeah, what’s the story there? Yeah, absolutely. I mean, I think, you know, the testosterone hormone is, I mean, listen, there’s androgen receptors on neural tissue, on neural axons. Pretty much everywhere. Exactly. So, you know, the binding capacity of testosterone and influencing different tissues within the body, I touched on, you know, muscle tissue, but you know, the ligaments, the tendons, even bone to some extent, you know, testosterone is potential to influence that in terms of removing osteopenic kind of characteristics, et cetera. So yeah, it’s a magic hormone, let’s say, with many, many end impacts in terms of adaptation.

Andrew Huberman (18:17):

I definitely want to get back to your trajectory, but as long as we’re on the interactions between androgens, testosterone and its derivatives and different tissues, you know, from the work that you did as a PhD student and throughout your career, could you say that there are some general principles of training that favor testosterone production in terms of that somebody who’s not an elite athlete could use, somebody who’s already adapted to weight training somewhat, like they know the difference between a dumbbell and a barbell, and they know the various movements, they’re not going to damage themselves, but once they’re doing that, I mean, I’ve heard shorter sessions are better than longer sessions, but in rep loads, now there’s a lot of parameter space, but if you were going to throw out some of the parameters that you think are most important to pay attention to for the typical person who’s trying to use weight training to build or maintain muscle, lose body fat, so body recomposition, and or stay strong and healthy for sport of a different kind.

Duncan French (19:17):

Yeah, so the work that we obviously, you know, I was exposed to back in my PhD, it was a double-edged sword, and as much as testosterone is really stimulated by an intensity factor and also a volume factor, now growth hormone is a little bit different, that’s largely driven by an intensity factor alone.

Andrew Huberman (19:33):

Oh, really? I always thought that growth hormone was driven by volume, which just goes to show you, no, no, no, no, I think you’re probably right, it just goes to show you that most of what’s out there on the internet is completely, not only is it wrong, it’s usually backwards, so no, trust, no, trust your instinct, because I think people just make this stuff up, right? Because it’s very hard to measure growth hormone and testosterone, and I can’t imagine most of the stuff that I see out there, they’re taking drips and, you know, measuring free versus bound and all this kind of stuff, but that’s what you do in laboratory.

Duncan French (20:06):

Right, yeah, you look at total composition and you look at how much of that is free circulating in the system, how much is bound, and therefore biologically active, bound to receptor creating an adaptation. But yeah, coming back to testosterone in terms of the training strategies, it’s largely driven by both an intensity and a volume factor. So if you look at many of the exercise interventions that we use to try and investigate and interrogate testosterone, it was usually, you know, a six by 10 protocol. So you’re touching- Six by 10, meaning? Yeah, six sets of 10 repetitions, which is quite a large, you know, 60 repetitions is quite a large volume for a single exercise, and that was usually pitched at about 80% of a one repetition max intensity.

Andrew Huberman (20:51):

Okay, so 80% of the one rep max, six sets of 10 reps separated by rest of like- Two minutes. Two minutes, which is actually pretty fast.

Duncan French (20:59):

At least to me. Anytime you see these two to three minutes,

Andrew Huberman (21:01):

when you’re actually watching the clock, those two minute rest periods go by pretty fast.

Duncan French (21:05):

By the third, fourth set, you’re dying for more, yeah. And I think, you know, we formulated that kind of exercise protocol to really target, you know, the release of testosterone and try and drive up these anabolic environments to study the endocrine, you know, consequences. But I think that’s the type of protocol that is most advantageous for driving anabolic environment. And that was it for the workout?


Yeah, I mean, we would do that in a back squat. So, you know, multi-joint, you know, challenging exercise, multi-muscle, multi-joint, 80% loads of your one repetition max, and then six by 10. We did play around with, you know, your classic German volume type 10 by 10 kind of protocols, but they were just unsustainable at that 80%. The key to what we also did was we always adjusted the loads to make sure that it was 10 repetitions that were sustained. So if the load was too high and an athlete or participant had to drop the weights on the sixth repetition, we would unload the bar and make sure they completed the 10 repetitions. Bringing me back to the point of it’s an intensity and a volume derivative that is going to be most advantageous for testosterone release.

Andrew Huberman (22:19):

That’s really interesting. And one thing that you mentioned there is especially interesting to me, which is you said, when you go from six sets of 10 repetitions to 10 sets of 10 repetitions, it’s not as beneficial and might even be counterproductive. But to me, the difference between six and 10 sets is only four sets. It doesn’t even sound that much. So that sort of hints at the possibility that the thresholds for going from a workout that increases testosterone to a workout that diminishes testosterone is actually a pretty narrow margin.

Duncan French (22:48):

Yeah, and I think it comes back to that intensity factor then. You know, what we saw with that 10 by 10 protocol really sees pretty significant drop-offs in the load. And again, we’re trying to stimulate with intensity, with mechanical strain through intensity, as well as metabolic strain through volume. And I think that’s the paradigm that you’ve got to look at is that the mechanical load has to come from, you know, the actual weight on the bar and the volume is the metabolic stimulus. How much are we driving lactate? How much are we driving, you know, glycogenolysis in terms of that type of energy system for, you know.


Executing a 10 by 10 protocol. And what we often saw was just a significant reduction in the intensity capabilities of an athlete to sustain that. So we shortened the volume to try and maintain the intensity.

Andrew Huberman (23:37):

Interesting. And you could imagine just taking very long rest, keeping the session, being a big lazy bear in training. I sometimes do this. I tell myself I’m going to work out for 45 minutes and then two hours later I’m done. But not because I was huffing and puffing the whole time, but because I was training really slowly. Is there any evidence that training slowly can offset some of the negative effects of doing a lot of volume?

Duncan French (23:59):

Well, it’s an old adage of, you know, two responses to your question. I mean, the first one I would say, you know, there’s a difference between 10 sets of six and six sets of 10. And I think that comes back to the volume conversation. You know, six sets of 10 is driving up metabolic stimulus. If you’re doing 10 sets of six, you can probably take it to a higher intensity, but you’re not going to get the same metabolic load. You’re not going to get the same internal metabolic environment that drives the lactate release, that they will then signal, you know, further anabolic testosterone release because of the lactate in your body. That’s a key consideration. The rest is often the consideration that’s overlooked out there in general population and in many sporting environments. You know, that the rest is as important a programming variable as the load and the intensity of the load, the volume, et cetera. And yes, if you remove, if you extend the volume, if you extend the duration of your rest periods, what you’re ultimately doing is influencing that metabolic stimulus again. You’re allowing the flushing of the body, the removal of waste products, you know, lactate to be, you know, removed from the body. And then the metabolic environment is reduced.

Andrew Huberman (25:11):

So you want, so if I understand correctly, you want to create a metabolic stress. Absolutely. So the way that I’ve been training slow and lazy is not necessarily the best way to go. I could, in theory, do a 45 or 60 minute session where I pack in more work per unit time. I’m not going to be able to, quote unquote, perform as well. I won’t be able to lift as much. I’m going to have to, you know, unweight the bar between sets or maybe even during sets if I have someone who could do that. But it sounds like that’s the way to go. So it’s got to be, so this, the old adage of high intensity short duration is probably the way to go.

Duncan French (25:47):

Correct. And, you know, in layman’s terms, if the same objective, the same training goal is just muscle tissue growth, and we’re not talking about maximal strength or any of those types of parameters. We’re just talking about growing muscle. If there’s an athlete A and they do six sets of 10 with two minutes rest, and there’s athlete B that does six sets of 10 with three minutes rest, athlete A will likely see the highest muscle gain, muscle hypertrophy gains, because of the metabolic stimulus that they’re driving with the shorter rest periods.

Andrew Huberman (26:15):

Interesting. For all the years that I’ve spent exploring exercise science and trying to get this information from the internet and various places that this is the first time it’s ever been told to me clearly. So basically I need to put my ego aside and I need to not focus so much on getting as many reps with a given weight and keep the rest restricted to about two minutes, get the work in, and then I’ll derive the benefits.

Duncan French (26:42):

I mean, you’ve absolutely nailed it, to be honest. And again, if you think about human nature and how we approached, we’re inherently lazy, right? As humans, we want to take that rest. We want to take the time out to recover and feel refreshed, but we’re trying to create a training stimulus. We’re trying to create a very specific stimulus internal to the body. And that is often driven by the metabolic environment at that moment in time. Now, if we allow the metabolic environment to change by extending the rest periods, we’re not going to see as beneficial gains at the end of it. Very interesting. It is very much a motivational and ego thing.


Rather than saying, okay, I’m going to push my loads as high as I can and really challenge maximal strength, do fewer repetitions, take longer periods of time. It’s a completely different approach to training. It’s a different end goal.

Andrew Huberman (27:30):

Interesting. And you mentioned lactate. So it seems still a bit controversial as to what actually triggers hypertrophy. You hear about lactate buildup or people that, the common language is the muscle gets torn and then repairs, but I don’t know, does the muscle actually tear?

Duncan French (27:45):

I mean, microtrauma. Okay, microtrauma. Disruption of the mic within the muscle tissue.

Andrew Huberman (27:50):

Interesting. And we’re talking now about non-drug assisted people who’s, let’s just say, let’s define our terms here. That whose testosterone levels are within the range of somewhere between 300 and 1,500 or whatever, 1,200. Because it does seem that athletes who take high levels of exogenous androgens can do more work and just get protein synthesis from just doing work. I’ve seen these guys in the gym, right? That’s the hotel signs are not that hard to spot where they’re just doing a ton of volume, not necessarily moving that much weight. They’re just bringing blood into the tissue. And then they’re loading up on, they’re eating a ton of protein, presumably because they’re basically in puberty part 15. Right? They got in their 15th round of puberty where during puberty, you are a protein synthesis machine. I mean, to me, that’s pretty clear about puberty. Interesting.


And then in terms of, because I know the audience likes to try protocol. So you described a protocol very nicely. What about day-to-day recovery? I mean, the workout that you described is intense, but short. How many days a week can the typical person do that and sustain progress?

Duncan French (29:04):

Yeah, I mean, I think that comes back to your training age and your training history. Obviously there’s a resilience and a robustness with an incremental training age. So that’s not a protocol that I would advise anyone to go out and start tomorrow. They’ll be mopping them up.


But at the same time, it’s also relative, right? So 80% of your maximum at a young training age is still 80% versus, I’ve been training 10 years, it’s still 80%. But yes, the mechanical load is gonna be significant. It’s just more tonnage, right? But yeah, I think a protocol like that, we would look at two times a week, something that’s pretty intensive like that. Because again, it comes back to the point you make is that you really need to be, for want of better terms, suffering a little bit through that type of protocol, both in terms of the challenge of the load, but also being able to tolerate the metabolic stress that you’re exposed to. It’s a bit of a sicko feeling, right? Because of the lactate that you’re driving up. So I wouldn’t promote as an athlete doing that type of modality multiple, multiple times, unless you’re from the realms of bodybuilding. And then you really, that’s the sole purpose of what you’re trying to achieve. Most athletes in most sports have diverse requirements in terms of outcomes that they’re trying to achieve. They’re not just targeting muscle growth. Muscle growth is a conduit to increase strength, increase power, increase speed, obviously. So yes, trying to get bigger cross-sectional area of a muscle means that we can produce more force into the ground or wherever it may be if we’re a locomotive athlete. But usually sports men and women are not just purely seeking muscle growth. They look for different facets of muscle endurance or maximal muscle power, muscle strength. So then you’ve gotta be very creative in how you build the workout. If it’s a bodybuilder, absolutely. They’re chasing muscle growth and they’re gonna do so with these types of protocols, which sees high intensities and high volumes of workload on a pretty regular basis. If it’s just somebody, a weekend warrior that wants to keep in shape and look good, I would say two times a week for a really challenging workout like that. And then flex the other types of workouts within the week to have more of a volume emphasis where you reduce the intensity and you might just look at larger rep ranges from 12 to 15 to 20. Another workout where you’re looking at reducing the volume but increasing the intensity and really trying to drive different stimulus to give you more end points of success.

Andrew Huberman (31:35):

Great, no, that’s really informative. Along the lines of androgens and intensity, when I think intensity, I think epinephrine, adrenaline. And since you have a background in catecholamines and testosterone, last time I was here at the USC Performance Institute, we had a brief conversation and I want to make sure I got the details right, that in the short term, and a big increase in stress hormone can lead to an increase in testosterone, like a parachute jump. But so stress can promote the release of testosterone. That was news to me. We always hear about stress suppressing testosterone, stress suppressing the immune system, all these terrible things. But in the short term, you’re saying it can actually increase the release of testosterone. So I have that, right? Correct, yeah. And so then the second question is, does my cognitive interpretation of the stressor make a difference? In other words, if I voluntarily jump out of a plane with a parachute, does it have a different effect on my testosterone than if you shove me out of the plane against my will? Or presumably with a parachute.

Duncan French (32:46):

Right. I mean, so this was what all my PhD work was looking at, was the exposure to a stressor and the pre-arousal of how your body essentially prepares for that stressor and then how it manages it throughout the exposure to the stress. And it was actually motivated from parachute jumpers. There was an older study looking at parachute jumpers into combat. And then they were studying the cortisol, the stress response and the epinephrine response of these parachute jumpers. So we got us thinking about, hold on, there’s certain workouts that you do that are just the daunting. It’s like, okay, it’s squat Saturday or whatever it may be. Oh my gosh, this is going to destroy me.

Andrew Huberman (33:32):

Or I have to talk to this person I don’t want to talk to. Or what, right? I mean, something, or PhD dissertation exam or something.

Duncan French (33:38):

Giving public speaking or whatever it may be. Now, we used a resistance training protocol that these athletes knew was going to be very, very challenging. It’s going to be, that it’s going to have some anxiety to doing it. They knew there were going to be some physical distress from doing it. And therefore, their mindset of how they were going to approach that was already set. So what we saw prior, 15 minutes prior to the start of an exposure to the workout, the epinephrine, the neuro adrenaline, the adrenaline was already starting to prepare the body sympathetically to go into what it knew was going to be a very, very challenging workout. So that brings you back to exercise preparation, competition for certain preparation, preparation for certain competition, excuse me.


Pre-workout routines, the use of music, all these different things that we know can now anecdotally in the gym, we put into place. But the data that I presented showed that it was the first of its kind to show that this link between epinephrine and norepinephrine release and arousal and then consequent performance. So force output throughout the workout was intimately linked.

Andrew Huberman (34:53):

So what was the takeaway there? Is it beneficial for people to get a little stressed about the upcoming impending event, whether or not it’s a lift in the gym or whether or not it’s talking to somebody that you might be intimidated to talk to or an exam? Is the stress good for performance or is it harmful?

Duncan French (35:13):

Yeah, and I think that’s a great question. And I think I can only talk to physical exertion, which is what we were exploring. And I don’t want to tread on the toes of the psychologist with flow state and these types of things, because clearly.

Andrew Huberman (35:26):

I think you’re in the position of scientific strength on this one. I think you have the leverage. I mean, most, you know, I have a lot of friends in that community, as I’ll just say, as a buffer to the answer you’re about to give, that there’s very little science around flow and there’s very little neuroscience related to most psychological states anyway. So I think we’ve got a lot of degrees of freedom here.

Duncan French (35:47):

All right, I can breathe easy, thank you for that.

Andrew Huberman (35:49):

Yeah, I’ll be, anything you like, credit Duncan, anything you dislike, send the mean comments to me.

Duncan French (35:57):

All right. Yeah, I think from my data, certainly the greater arousal, the higher the performance was from a physical exertion perspective. And I think that was the intriguing part of some of my findings, where there’s definitely an individual biokinetics to some of these hormonal kind of releases. And as much as those guys that had the highest adrenergic response in terms of epinephrine release, norepinephrine release, also sustained force output for a longer period of the workout than those that didn’t. So the individuals that had a lower stimulus of the sympathetic arousal, let’s say, certainly didn’t perform as well throughout the workout. Now, the intriguing thing then becomes is, okay, and I think this really segues into what we’re doing here with combat athletes, with mixed martial artists. You know, there’s a philosophy, there’s a paradigm now for myself in terms of the exposure, repeat exposure. You know, the more you do that challenging workout, do you get the same psychological stimulus? Do you still get the same stress response? And the assumption is unlikely. You know, you accommodate, you become accustomed to the stressor, your body will therefore adapt. And that’s the classic overload principle, right? And you then need to take the stressor down a different route. But I think when you look at, you know, the athletes that we work with here, it’s a fist fight at the end of the day. There’s nothing more stressful than that. But I think just the exposure to the rigors of training, to understand the bad positions, the bad situations, to know that they can get out of certain situations, out of certain, you know, submission holds or whatever it may be, I think that really ties in with some of my PhD work in terms of what these guys do to approach what is, you know, a really challenging sport and arena in mixed martial arts.

Andrew Huberman (37:45):

Yeah, it’s definitely the extreme of what’s possible in terms of asking, does stress favor or hinder performance? Because yeah, like you said, at the end of the day, it’s someone trying to hurt you as much as they possibly can within the bounds of the rules and you’re trying to do the same. So that’s, you know, I find that your thesis work fascinating. Were you never to be at the UFC Performance Institute, luckily they made the right choice and brought you here, but were you have never to come here, I was still fascinated by this because over and over we hear that stress is bad, stress is bad, stress is bad, but everything I read from the scientific literature is that stress and epinephrine in particular is coupled to the testosterone response to performance and to adaptation, provided it doesn’t go on too long.


So unless I’m saying something that violates that, I mean, that’s your work. So it’s a really important and beautiful work and I refer to it often. So I’m just glad that we could, you know, bolt that down because I think the people need to know this, that that discomfort is beneficial. Now there’s another side to this that I want to ask about, which is the use of cold. In particular things like ice baths, cold showers, or any other type of cold temperature exposure, you know, in theory that’s stress also, it’s epinephrine. And so how should one think about the use of cold for recovery? So if it’s stress, how is, if stress, if cold causes stress, then how is cold used for recovery? That’s what I don’t understand. And maybe you just want to share your thoughts on that.

Duncan French (39:31):

Yeah, no, and I think, you know, it’s a great question. And I think the jury is still out there certainly, knowing some of the conversations that we’ve been having. But I think, you know, when we talk about stress, it’s your classic fight, flight, or freeze approach. And, you know, throwing your body into, you know, a cold tub, an ice bath, or whatever it may be, certainly is going to have a physiological stress response. Now, people are using that for different end goals. And again, I think that’s where the narrative has to be explained. If you are using the stress specifically to manage the mindset, to use it as a specific stress stimulus, that’s the same as me doing six by 10, 80%. You know, you’re just trying to find something to disrupt the system, to do something that’s very, if you want a better term, painful, discomfort, whatever. You’re just finding a stressor and then being able to manage the mindset. But if you’re using cold, specifically from a physiological perspective, to promote, you know, redistribution of vascularity, of blood’s flow, you know, to different vascular areas of muscle that you feel have gone through a workout, that are damaged or whatever it may be. I think there’s, we’ve got to understand what that stress mechanism is. And, you know, the data, the literature, is certainly still out there with respect to cryotherapy and cold baths and some of these, you know, high, these cold exposures in terms of what they do at the level of the muscle tissue. If that’s the target, if you’re trying to promote a flushing mechanism, or you’re trying to promote redistribution of the blood flow, what you’ve got to understand is that cold is going to clamp down every part of the vascular system. And we’ve really got to understand how the muscle would be redistributed to areas of interest. So, you know, I think the stress response is a real thing with respect to, you know, cold exposure. But I think the narrative around what are you using the cold for has to precede the conversation. Because yes, it’s, you know, it’s like putting your hand over a hot cold. You know, that’s a stress the same way as jumping in a cold bath is.

Andrew Huberman (41:44):

I think most people don’t realize that. You’re going to get the epinephrine release from holding your hand up too close to the flame, and you’re going to get it from getting in the ice bath.

Duncan French (41:52):

And your body doesn’t know the difference, right? Your body does not know the difference. It has a, you know, a primordial kind of physiological response that it’s created over millions and millions of years. And I think that physiology is not changing, and it’s fixed in a particular way right now, that it doesn’t understand the difference between whether it’s six by 10 doing a challenging workout over here, whether it’s putting my hands on the hot cold, whether it’s a lion stood in front of me or whatever. That epinephrine response from the level of the brain down to the whole signaling cascade is the same.

Andrew Huberman (42:26):

And cold, I’ve heard, can actually prevent some of the beneficial effects of training, that it can actually get in the way of muscle growth, et cetera.

Duncan French (42:38):

Yeah, there’s some pretty robust data out there now showing that it definitely has an influence on performance variables like strength and power in particular, but absolutely in terms of muscle hypertrophy. And there’s a big kind of theme in the world of athletic performance right now in terms of periodization of cold exposure as a recovery modality. When do you use cold? Should you be using cold for recovery in periods of high training load when you’re actually pursuing maybe general proprietary work? We’re actually trying to pursue muscle growth. Well, that’s usually where you get the most sore. It’s usually where you feel the most fatigued, but it’s probably not the most beneficial approach to use an ice bath in that scenario because you’re dampening, you’re dulling the mTOR pathway and the hypertrophic signaling pathway. Whereas in a competition phase where actually quality of exercise and quality of execution of skill and technical work has to be maintained, you want to throw the kitchen sink of recovery capabilities and recovery interventions in that scenario because you now, the muscle building activity should be in the bank. That should have been done in the general preparatory work. And now you’re focusing on technical execution. So you’re absolutely right.

Andrew Huberman (43:57):

No, it’s interesting. So if I understand correctly, if I want to maximize muscle growth or power or improvements and adaptations, then the inflammation response, the delayed onset muscle soreness, all this stuff that’s uncomfortable and that we hear is so terrible is actually the stimulus for adaptation. And so using cold in that situation might short circuit my progress. But if I’m, you know, I don’t know that I’ll ever do this, but if I were to do an Ironman or something or run a marathon under those conditions, I’m basically coming to the race, so to speak, with all the power and strength I’m going to have. And so there, reducing inflammation is good because it’s going to allow me to perform more work, essentially.

Duncan French (44:41):

Absolutely. Yeah, you have to be strategic about when you use some of these interventions. And, you know, the time when you’re preparing for a competition is not the appropriate time, excuse me, is the appropriate time when you want to drive recovery and make sure that your body is optimized. You know, when you’re far away from a competition, you know, date or, you know, out of season or whatever it may be, and you’re really trying to just tear up the body a little bit to allow it to, it’s natural, you know, healing and adaptation processes to take place. Well, you don’t want to negate that. You know, you want the body to optimize its internal recovery, and that’s how muscle growth is going to happen, so. So interesting. There’s a time kind of consideration that you need to make with these interventions, for sure.

Andrew Huberman (45:24):

At the UFC Performance Center, are the fighters periodizing their cold exposure, or are they just doing cold at will?

Duncan French (45:32):

Well, it’s not just the UFC. And again, I talk about my personal experiences with different sports. I think just education around where science is at and our understanding of concepts like the use of cold exposure for recovery, ice bath. You know, everyone wants to jump in an ice bath. But I think as we’ve stepped back and scientists have started to say, have started to figure out and look at some of the data, you know, we’re now more intuitive about, well, actually that might not be the best or the most optimal approach. And I think that’s any given sport. So yes, certainly here at the UFC, we’re trying to educate our athletes around, you know, appropriate timing. And it’s the same with nutrition. It’s the same with an ice bath intervention. It’s the same with lifting weights. It’s the same with going for a run or working out on the bike. You know, there’s tactics to when you do things and when you don’t do things. And I think, you know, stress and cold exposure, we have to have a consideration around that as well. But it’s not just, you know, MMA fighters. That’s any athlete. And I think it’s the best professionals, the most successful professionals do that really well. They listen, number one, they educate themselves and then they build structure. And I think, you know, at the most elite level, we always talk about it here at the UFC, but the most elite level, you’re not necessarily training harder than anybody else. Everybody in the UFC trains hard. Like everyone is training super hard.


But the best athletes, the true elite levels are the ones that can do it again and again and again on a daily basis and sustain a technical output for skill development. Therefore, their skills can improve or physical development, their physical attributes can improve. So that ability to reproduce on a day-to-day basis falls into a recovery conversation. Now, when is the right time to use something like an ice bath and when isn’t is part of the high-performance conversation for sure.

Andrew Huberman (47:26):

So really they’re scientists, they’re building structure, they’re figuring out variables, but it sounds like the ability to do more quality work over time is one of the key there.

Duncan French (47:36):

I mean, it’s fundamental. I mean, garbage in, garbage out, quality in, quality out.


But in our sport, you know, I talk about, you know, mixed martial arts, it’s truly a decathlon of combat. So there’s so many different attributes, whether it’s a grappling, whether it’s a wrestling, whether it’s a transition work, whether it’s a standup striking. So the different facets of a training program in this sport are significantly large compared to something like, you know, a wide receiver in football. And that’s no disrespect for wide receivers, but they run routes. They’re gonna run a route, a passing tree, and that’s all they need to do. These guys have to be on the ground. They gotta be great on the ground. They gotta be great standing up. They gotta be great with the back against the fence. There’s so many different kind of facets to our sport. So managing the distribution of all the training components is one of the biggest challenges of mixed martial arts. And the best guys get that right. They allow their body to optimize the training. And remember, why are we doing training? We’re doing training for technical and tactical improvement.


Now, if your body is fatigued or you just can’t expose yourself to more tactical development or technical development, then you’re essentially doing yourself a disservice. You’re gonna be behind the curve with respect to those guys that can reproduce that day in, day out.

Andrew Huberman (48:55):

On the topic of skill development, regardless of sport, we hear all the time, and it certainly is intuitive to me, that the person who can focus the best will progress the fastest. But it’s kind of interesting, sometimes I talk to athletes and they seem a little bit laid back about their training sometimes, and yet they obviously know how to flip the switch and they can really dial in the intensity. Do you think that there are optimal protocols for skill learning in terms of physical skill learning? Like, could it ever be parameterized like the six sets of 10 reps? And this gets to the heart of neuroplasticity, which is still, it’s not a black box, but it’s kind of a black box with portions of it illuminated, I like to say. But what are your thoughts on skill development? Is there, for somebody that wants to get better at sport, do you recommend a particularly long or short training session? It does intensity matter, or is it just reps?

Duncan French (49:58):

Yeah, I think, no, it’s not a volume driven exercise. It’s a quality driven exercise. And listen, my expertise is not in motor learning and motor skill acquisition. I tend to default to Dr. Gabrielle Wolf here at UNLV for that, she’s one of the leading proponents in this area. But if you look at true skill development, it is about rehearsal of accurate movement, accurate movement mechanics. And as soon as that becomes impacted by fatigue or inaccurate movement, you’re now losing the motor learning. You’re losing the accuracy of the skill that people can call it muscle memory or whatever they want, right? But essentially you’re grooving neural axons to create movement patterns, and they’re situational throughout sport, right? Whether it’s a cruyff turn in soccer or a jump shot in basketball or a forehand down the line, you can carve out that particular posture and position and skill and you can isolate it and you can drill it again and again and again. Now, as soon as fatigue is influencing that repetition, it’s time to stop. And the best coaches understand that. They understand that it’s quality over quantity when it comes to skill acquisition. So to answer your question in a roundabout way, I would say, yes, it’s shorter sessions that are very high quality. And I think the best athletes in my experience are the ones that consciously and cognitively are aware of it at every moment of the training session. They should leave the training session not necessarily just physically fatigued, but mentally fatigued because they’re completely engaged in the learning process.


The problem then becomes, okay, if we just do lots of 30 minute sessions, we’ve got to do a lot of 30 minute sessions to get the volume exposure of the repetition and the rehearsal of the skill again and again and again. So it’s a bit of a paradox. It’s a bit of a double-edged sword, but a three hour session versus a 90 minute session, we’ll take the 90 minute session any day when it comes to skill acquisition because that’s going to be driven by quality over quantity.

Andrew Huberman (52:09):

Training and skill learning is incredibly mentally fatiguing. I’ve often wondered why when one works out hard, whether or not it’s with a run or with the weights, why it’s hard to think later in the day. Yeah, there really does seem to be something to it. And I’ve wondered, is it depletion of adrenaline, dopamine? I sometimes think it might be dopamine and here I’m totally speculating. I don’t have any data to support this, but if you hit a really hard workout or run early in the day oftentimes the brain just doesn’t want to do hard mental work, which gives me great admiration for these athletes that are drilling their mind and body all day, every day, with breaks. But so what are your thoughts? What leads to the mental fatigue after physical performance?

Duncan French (52:58):

Well, again, I don’t want to talk out, talking to the man here, you know, this.

Andrew Huberman (53:01):

Well, we’re just two scientists speculating on this point. Up until now, you’ve been giving us concrete peer-reviewed study-based feedback on my questions, but if we were to speculate, and I think this is a common occurrence, people think if I get that really good workout in in the morning, I feel better all day. That’s true, unless that workout is really intense or really long. And then you just, the mind just somehow won’t latch on to mental work quite as well.

Duncan French (53:30):

I mean, just philosophically, you know, I think there’s a coming back to this kind of stress consideration, you know, like a public speaking or taking an exam. I mean, if you have an amazing coach who is setting up training in a particular way, it’s challenging, there’s a strain related to it. And I’m not talking physical strain, I’m talking figuring things out, you know, figuring out the skill. And I think that can be stressful, like the learning process can be stressful. So, you know, we’ve touched on stress. I also think if they hit the right technique, you know, that reward center in the brain, that dopamine shot is gonna fly up there. And there’s only so many times that we can get that before that becomes dampened. And I think there’s an energetic piece to it. You know, there’s the fueling of the brain. There’s the carbohydrate fueling exercise that actually the strategy around how you fuel for learning and fuel for physical training is actually pretty similar. Glucose. Yeah, it’s glucose, it’s sugar at the end of the day, right? So, you know, are you fueling accordingly around your training sessions? Be that very physical. Cause everyone thinks, okay, you know, I’m gonna jump on a treadmill and I’m gonna bang out, you know, 15 sprints at max effort. And I’m gonna, you know, be dropping off and lying on the floor at the end of it, I need to refuel. Well, what about the refueling of the brain in a very demanding exercise or drilling session where you’re looking at technique that you’re trying to figure out that’s very challenging for your mind to figure out the complexity of it, but still needs to be fueled or refueled afterwards. And I think that’s obviously, you know, might be an area where athletes do themselves a disservice by not appropriate fueling from what might be considered to be a lower intensity session, but the cognitive challenge has been significantly high.

Andrew Huberman (55:20):

So they’re doing skill work or drill work and it’s taxing the brain and they’re thinking, oh, you know, I wasn’t, you know, pushing hard lifts or doing sprints. And so I can just go off the rest of my day, but then their mind is drifting.

Duncan French (55:34):

Yeah, I mean, I speculate. Yeah, that seems very reasonable.

Andrew Huberman (55:37):

I mean, I know that I’m here and presumably with the other athletes you’ve worked with, nutrition is a huge aspect of that. And I think the general public can learn a lot from athletic nutrition because at the end of the day, the general public is trying to attend to their kids, attend to their work, whether or not they’re lawyers or whatever. They need to focus. Nutrition is a barbed wire topic. Oh yeah. But since we’re free to do what we would do if we were just sitting in each other’s offices, which is to just speculate a bit, for the typical person, right?


Do you think these low carbohydrate diets, typical person who exercises, runs, swims, yoga, lifts weights, maybe not all those things, but some collection of those, pushes themselves to do those things and to do them well, but isn’t necessarily a highly competitive athlete? Do you think that nutrition that doesn’t include a lot of glucose, doesn’t include a lot of carbohydrates is a problem? Or is it okay? What do you recommend for athletes? What do you recommend for typical people?

Duncan French (56:42):

Yeah, again, disclaimer, I’m not a dietician, but I-

Andrew Huberman (56:46):

That’s okay, the dieticians don’t know what to recommend to athletes either. And I say that from having to spend a lot of time with the literature now, it’s a complete mess. It’s like, I thought we didn’t understand anything about the brain. The nutrition science stuff is all over the place. So I think we have, again,

Duncan French (57:02):

a large series of freedom. Right, right, right. I mean, I think it comes down to metabolic efficiency. So we would never advocate, I never say never, right? Okay, but we rarely advocate a high-performance athlete in a high-intensity intermittent sport like MMA, being totally ketogenic or- You do not recommend that? No, because at the end of the day, some of those high-intensity efforts usually require carbohydrate fueling for the energy produced at those high intensities. So we try to navigate around that. Now, listen, there are fighters in the UFC and elsewhere. Matt Brown is a great example who promotes the ketogenic approach, and it works for him. But we look at the science and the nature, the characteristics of our sport, and we don’t necessarily promote that.

Andrew Huberman (57:56):

Can I interrupt you real quick? What about ketones for people that are ingesting carbohydrates? This is an interesting area because people always hear ketones, and they think, oh, I have to be ketogenic to benefit from taking ketones. But there are a number of athletes, and recreational athletes now as well, taking liquid or powder-based ketones even though they do eat rice and oatmeal and bread and other things. So are there any known benefits of ketones even if one is not in a state of ketosis?

Duncan French (58:27):

So the use of ketones that I’m primarily aware of is in our sport is after the event, in terms of the brain health, with athletes potentially taking trauma to the brain, et cetera, and looking to maintain the fueling and the energy supply to the brain. But yes, it’s probably a little bit out of my remit, so I don’t want to talk on that because I’m not fully familiar with that.

Andrew Huberman (58:52):

Well, I’ve heard that ketones after head injury can provide a buffering component. It’s not going to reverse brain damage, but it might be able to offset some of the micro damage.

Duncan French (59:01):

Right, so that’s how we use it, just to sustain the energy supply to the brain that might be compromised through brain trauma. So that’s why we use ketones. To come back to the original question, if it’s a general population, then yes, I think there’s a place to argue that actually being on a ketogenic diet at times, and maybe it’s a cycling exercise, maybe not, I don’t mean cycling a bike, I mean cycling ketosis is beneficial because I think it’s going to lead to better metabolic management and metabolic efficiency. Those lower intensities where we should be fueling our metabolism with lipids and fats, clearly the Western diet and the modern day diets is heavily driven by processed foods and carbohydrates that people become predisposed to utilization of that fuel source above lipids use, fat use, intensities that are very low. So some of our data with the fighters shows that as well. But I think the challenge for us is that we’re working with a clientele that require high intensity bouts of effort. So fueling appropriately is very important for that. Now we use tactics here where we essentially have athletes on what you would say kind of, is it a largely a ketogenic diet, but then we will fuel carbohydrates around training sessions. So we’ll do very timed exposure to carbohydrates. So it’s not- Post training. Post training, immediately pre, during, and then immediately post. And then the rest of their diets, breakfast, lunch, and dinner, what would look like ketogenic type approaches. So we’re trying to be very tactical in the exposure to maximize the intensity for the training and then return to a metabolically efficient diet, which is heavily reduced in carbohydrate because we’ve fueled the sessions at need.

Andrew Huberman (01:00:55):

I’m smiling because once again, this place, the UFC Performance Center is doing things scientifically, which to me, the idea, and I’m pleased to hear that because to me, this idea that the ketogenic diet is the best and only diet or carbohydrates and low protein diets are the best diet, it’s ludicrous. Then you mentioned metabolic efficiency. I think some people might be familiar with that term, some perhaps not, but the way I understand metabolic efficiency is that you teach the body to use fats by maybe doing long bouts of cardio, maybe lowering carbohydrates a bit. So teaching the body to tap into its fat stores for certain periods of training.


And then you also teach the body to utilize carbohydrates by supplying carbohydrates immediately after training and before training. You teach the body to use ketones and then you use them at the appropriate time as opposed to just deciding that one of these fuel sources is good and all the others are bad or dispensable. Do I have that correct?

Duncan French (01:01:56):

You nailed it. I mean, from Bob Seabahar, formerly of USA Triathlon, is the guy that kind of came up with the concept of metabolic efficiency. But yes, you’re absolutely right. I mean, at low intensities of exercise or just day-to-day living, we shouldn’t be tapping into our carbohydrate fuel sources extensively, that’s for higher intensity work or the fight or flight needs of stress. If athletes or any individual has a high carbohydrate diet, they’re gonna start to become predisposed to utilizing that fuel source preferentially. Now, low intensity, that can be problematic, certainly for an athlete, because if they preferentially use carbohydrate at lower intensities, when the exercise demand goes to a higher intensity, they’ve already exhausted their fuel stores. So they can’t draw upon fat because the oxidization of that fat is just too slow. So they’re essentially now become fatigued because they’ve already utilized the carbohydrate stores. So what we try to do, yes, through diet manipulation and a little bit of exercise manipulation is, as you say, teach the body or train the body to preferentially use a specific fuel source, fat obviously at lower intensities and carbohydrate at high intensities. And we look at specifically the crossover point between the two tells a lot in terms of how an athlete is ultimately, how their metabolism is working.

Andrew Huberman (01:03:24):

Well, again, I’m smiling because I love this because it’s grounded in something real and scientific, which is that we have these different fuel sources. The body can adapt to use any number of them or one of them. I think most people are looking for that one pattern of eating, that one pattern of exercising that’s gonna be best for them or sustain them. And they often look back to the time when they felt so much better switching from one thing to the next, but the adaptation process itself is also key, right? Teaching the body.


So if we were to just riff on this just a little bit further, if somebody, I’ll use myself as an example since I can only speculate what other people’s current nutrition protocols are, but if somebody is eating in a particular way and they want to try this kind of periodization of nutrition, could one say, okay, for a few weeks, I’m going to do more high-intensity interval training and weight training, and I’m going to eat a bit more carbohydrate because I’m depleting more glycogen. Then if I switch to a phase of my training where I’m doing some longer runs, maybe I’m training less, maybe I’m just working at my desk a little bit more, then I might switch to a lower carbohydrate diet. Do I have that right? And then if I’m going to enter a competition of some sort, certainly not UFC or MMA of any kind, to be clear, not because it isn’t a wonderful sport, but because that wouldn’t be good for my other profession. But if I were going to do that, then I would think about stacking carbohydrates, ketones, and fats. Do I have that?

Duncan French (01:04:56):

I mean, I think, yeah, you said it eloquently. At the end of the day, you’re consciously understanding what the exposure to physical exertion is, and you’re flexing your diet accordingly. And I think- So it’s need-based eating. Exactly, and for one of the better terms, you can call it whatever fancy terminology there is out there, but yes, it’s needs-based eating, but you’re very conscious and cognizant of what is my current exercise status. If I’m taking some time off, then don’t gorge on the carbohydrates. We probably need to be cut. It’s going to be lower intensity work or even just habitual day-to-day walking around, doing your groceries. That doesn’t require massive amounts of glycogen storage and carbohydrate fueling. So you can potentially go more ketogenic in nature, oxidizing lipids for that fuel. If you are in a high period of high-intensity training, then you have to consciously flex your diet to support that. That’s not normal. You’ve made a change. You’ve elevated the demand. So the fueling requirements for the regenerator, not only fueling the exercise, but the regenerative requirements of your body after that type of work is going to be really important as well. So yes, take on more carbohydrates. So I think it’s consciously interpreting the nature of your diet against where you are at any moment in time.

Andrew Huberman (01:06:17):

Like that. I think the listeners in my podcast generally are experimenters. They are scientists of themselves, which makes me happy, obviously. And I like to think that they’re paying attention to the changes they’re making and how they’re affecting themselves. And they seem more open to trying things, provided they can do it safely, and seeing what works for them. And I’m certainly going to try some of the change up. I also am really a creature of habit. And I think the talking to you today, I realize I’m probably doing a number of things truly wrong in my training, but also that I don’t tend to vary my nutrition with my training quite as much as I should. I’m just locked into a protocol.


So we covered a number of things related to your PhD thesis work, but I cut you off early on related to your trajectory. After you finished your thesis, I know you were at Notre Dame for a while. Was that your first spot after your PhD thesis?

Duncan French (01:07:14):

No, no, I basically finished my PhD and I dropped into the British Olympic system for about 14 years. Oh my, okay. I was with, you know, I’ve done three full Olympic cycles with different sports and largely a strength and conditioning coach as a practitioner. I was always working in universities and academia alongside, you know, in terms of continuing to publish and write and do research and teach as well.

Andrew Huberman (01:07:42):

Because that explains the huge volume of publications. I don’t think people realize the work that goes into getting a quality peer reviewed publication. It’s not, what do they call it now on Instagram? Anecdata, where people would do something, want, you know, they have this experience and then they put in the world that it’s a, Anecdata are, I don’t even know that we should call it data, but so 14 years in working with the British Olympic team.

Duncan French (01:08:06):

Yeah, so with, you know, whether it was GB boxing primarily with the Rio, excuse me, the Beijing cycle, but also lightweight rowers and gymnastics. For the London Olympic games, that cycle I was the lead strength and conditioning and physical performance coach for British basketball. So GB basketball. I had about three years in the English Premier League with Newcastle United and the soccer team. And then for the Rio Olympic cycle, I was with Great Britain Taekwondo. So again, another combat sport. After I’d finished there, I kind of moved to the University of Notre Dame where I went into more of a managerial position working across all the different technical services, medical, nutrition, strength and conditioning, you know, psychology and whatever, sports science, whatever it may be. As the, you know, the director of performance sciences for Notre Dame athletics. And then after about 16 months there, the UFC came knocking and they recruited me out of Notre Dame. So it’s been a great ride. And lots of, you know, I’ve got, you know, lots of athletes have taught me a lot along the way. Lots of coaches, you know, every day is a school day. I still try and keep that mentality. And, you know, in this world, we call it white belt mentality. You know, it’s, you know, I’m a PhD. I’ve got 25 years of experience in high performance sport, but I still learn every single day from these people out on the mats and in the ring. And it’s impressive to see what they do.

Andrew Huberman (01:09:33):

Yeah, it certainly is. I got introduced to MMA just a few years ago. I think the first time I came out here was one of the first times I’d heard of MMA because I was kind of in my laboratory, you know, nose down. And it’s a really interesting sport because it incorporates so many different types of movement. As you said, you know, it’s not just stand up boxing. It’s just kicking. It’s every, you know, ground game, everything. And I’m still learning about it. But as you mentioned, going in with that beginner’s mind, the white belt mentality, what has been the most surprising thing for you in terms of being exposed to MMA in particular, as opposed to other sports? Like what’s unique about MMA fighters besides that they have this huge variety of tactical skills that they have to learn and perfect?

Duncan French (01:10:22):

Yeah, that’s a great question. I would say two things. I’m going to answer two questions. One actually reiterates what you’ve already said. Like the degrees of freedom in mixed martial arts are exponential, like no other sports, you know. We’ve got 11 different weight classes. We have men’s classes, we have women’s classes. We have, you know, kickboxers, wrestlers, jiu-jitsu fighters, judokas, you know, like karate fighters. You know, the stylistic backgrounds are infinite. We have, we’re a weight classification sport. There’s a whole issue relating to making weight and then rebounding to fight about 24 to 30 hours. Like just the variability in this sport, the considerations that you have to make are unprecedented compared to any other sport that I’ve worked with. And a lot of them go against and are the antithesis of what you would expect for high performance. You know, in terms of, we don’t always have a very clearly defined competition schedule. You know, once these guys fight, they don’t necessarily know when their next fight’s going to be. What’s the closest spacing of a fight? I mean, listen, I think the record is around, it’s just over a month, I believe. Goodness. So, you know, that’s a quick turnaround, but most of these guys are fighting, you know, three or four times a year, three times a year is pretty normal. The bigger fights, maybe two times a year. But invariably, the guys don’t know when that next date is going to be. So we’re in this gray area of, okay, what do we do? Like, are we taking some time off? Are we just going to do some general prep work? Are we going to try and keep this, you know, the knife sharpened?

Andrew Huberman (01:11:57):

In case I get- I didn’t realize this. In that way, it’s a lot like special operations.

Duncan French (01:12:02):


Andrew Huberman (01:12:03):

You don’t know when the call’s going to happen. They have to be ready at all times. There isn’t this, like, let’s get ready for season.

Duncan French (01:12:07):

Right. Yeah, like, when I was with the British Olympic Association, you know, I knew it was the British Open, the Spanish Open, the French Open, the European Championships, the Israeli Open, the American Open, the Canadian Open, the Olympic Games.

Andrew Huberman (01:12:19):

You know, I could- It’s a circuit in your brain. Right. You just plan, like,

Duncan French (01:12:23):

you know where all the targets are going to be. Here, it’s a moving target, because you might be just hanging out, doing some general prep work, and then you might get a short notice fight that give you a quick call, and it’s in six weeks or five weeks, and okay, I’ve got to ramp everything up really quickly. So that’s a real challenge in terms of just managing all these different components of mixed martial arts alone.


To come back to your question, the other thing which is truly fascinating about these individuals is just their mental resilience. And again, we’ve touched on it in the talk, but you know, the ability to do what they do on a daily basis, to look at all the different skill sets that they have to try and engage in and bring into their training, to do that and embrace the grind, embrace the process of just learning. The physical side of our sport is unprecedented, but the mental side, you know, we have a funny saying here, we always say it’s 90% mental apart from the 60% that’s physical. So, you know, it’s just more and more and more. And these guys’ ability to just do that on a daily basis is very impressive. Like their resilience, their internal drive and their resilience is really impressive to them.

Andrew Huberman (01:13:38):

All the fighters I’ve met here have been really terrific. It’s interesting. Every time I meet a fighter, how often I shouldn’t be surprising where they’re often very soft-spoken.

Duncan French (01:13:48):

Right. Always extremely polite. Yeah, yeah.

Andrew Huberman (01:13:50):

And fighting is such a, you know, it comes from a very primitive portion of the brain, right? But a large portion of the brain, nonetheless. But I think that’s another skill is.

Duncan French (01:13:57):

Nonetheless. But I think that’s another skill is that switch, you know? And again, that’s the recoverability piece, right? Like you cannot be type A or you cannot be like supercharged 24 hours a day because you’re gonna just fry your system, right? And I think that’s something else where we’re really trying to manage this whole process, be it through nutritional interventions, be it through education around sleep, be it through training program management, be it through psychological interventions. You know, you could look at fights and say like, these guys are gold. Like they’re red alert and they’ll run through a brick wall. But actually, again, their ability to turn it on and off means that they can do what they do. You know, they can bring it down and be very normal, very polite, very, you know, accommodating.

Andrew Huberman (01:14:41):

Maybe even better than most people, because, you know, one of the reasons I’m obsessed with human performance and high performance and people like fighters and, you know, elite military or even bodybuilders for that matter is that they experiment. Yeah. They find the outer limits of what’s possible. But one of the things that they have discovered as you’re describing is this ability to toggle between high alert states and calm states. Most typical people can’t do this. They see something that upsets them on the internet or something on the news or some external event pressures down on them and they’re stressed for many, many days and weeks. And sometimes it goes pathological, right? And this, I don’t say this as a criticism. It’s just that most human beings within our species, most members of our species never learned to either flip the switch or to just voluntarily toggle between states. I think athletes learn how to do that extremely well.


And it sounds like MMA fighters do that even better than perhaps many other athletes.

Duncan French (01:15:40):

I mean, yeah, there’s the odd one or two that we’d struggle with. But I think in terms of that chronic exposure, we see that coming from challenges around, cyclical weight cutting and metabolic disruption and metabolic injury, not necessarily from the psychological drive. They do understand that this is a job for them and the time on the mats. Most of them can turn it off a little bit and downgrade things when they’re off the mats. It’s impressive to see. Because again, like as a layman, just looking at the fight game, you think it’s gonna be crazy chaotic, 100 miles an hour, every hour of every day. But that’s clearly not the case. They manage their energy and their efforts pretty well.

Andrew Huberman (01:16:24):

So it’s a little bit like science, although maybe scientists could take a lesson from-

Duncan French (01:16:28):

Yeah, is it that evidence-based practice or practice-based evidence, right? I like that, that’s good.

Andrew Huberman (01:16:32):

A couple more questions. I can’t help myself. I know we talked about temperature earlier when we discussed cold, but I can’t help myself. I have to ask you about heat. Because earlier we were having a conversation about heat adaptation, about how long does it take for the human body or athlete or typical person that’s maybe exploring sauna or things of that sort to learn to be a better sweater? It sounds like something none of us would want to do. We all want to stay cool, calm, and collected. But one of the reasons to deliberately expose oneself to heat is for things like growth hormone release, et cetera. We can talk about this. But a couple of questions. One, is heat exposure stress in the same way that the ice bath or cold exposure is stress? Second one is, is there any difference there that’s important? And the other one is, how does one get better at heat adaptation? Or at least what are you doing with the fighters to get them better at dealing with heat? How long does that take? So the first question, just because I threw three questions at you, is heat stress like cold is stress?

Duncan French (01:17:38):

Yeah, I think it is. And I think heat shock proteins, for example, are driven by that stressful exposure to a changing environment. So I think we do graded response in terms of heat acclimation strategies. But yes, we’ve touched on it earlier in the conversation. For me, heat is still a stressor. And if it’s managed incorrectly, you can have detrimental responses rather than beneficial responses.

Andrew Huberman (01:18:06):

So barring like hyperthermia and death, like, I mean, obviously you heat up the brain too much, people will have seizures and die, but you lose neurons. But what’s the right way to acclimate heat? Taking into account that people are, you know, should check with their doctor, et cetera, we do all these disclaimers. But you know, but let’s say I, let’s just say I want to get better at dealing with heat or I want to extract more benefit from heat. Is, I mean, how many minutes a day are people typically exposing themselves to heat? How often and over how, what periods of time?

Duncan French (01:18:35):

Yeah, so we normally start with about 15 minutes of exposure. Now, if someone’s really lacking acclimation to heat, you know, you can do that in three, five minute efforts. Do you know what I mean? And actually take time. This is hot sauna? Yeah, hot sauna. Take time to stay.

Andrew Huberman (01:18:49):

200 degrees or something like Fahrenheit. Correct, yeah, yeah.

Duncan French (01:18:51):

200 Fahrenheit, yes. And we try to work up to 30 to 40 minutes to 45 minutes in the sauna continuous. Now, we have to understand, you know, what’s the advantage of heat acclimation for our athletes? Ultimately, their ability to sweat and to lose, you know, body fluids is going to be advantageous to their weight cut process. Their ability to make weight. It is a technique that these guys, some of these guys adopt. So if you don’t have, you know, high sweat rates, it means you’re gonna have to sit in the sauna for longer and longer and longer to get the same delta in sweat release. So the more acclimated you are, the more your body is thermogenically adapted, the more sweat glands you have, the small pores. You can sweat more, and therefore you’ll lose that fluid quicker and you spend less time in the sauna. So that’s why we do it, to try and promote, to limit the exposure. And it comes back to your first question, is it a stressor? Absolutely, it’s a stressor if you’ve got to spend, you know, two hours over, you know, over a four hour period, two hours of it sat in a sauna because you- Where the phone doesn’t work, so you can’t be, no, just, you know, people-

Andrew Huberman (01:19:57):

Yeah, where the phone doesn’t work, so you can’t be, no, just, you know, people will divorce them from their phone and that’s a stressor in itself.

Duncan French (01:20:04):

Right, I mean, yes, I think, you know, there’s a, you know, what we do is we, like anything, we build up in temperature, but we build up in volume of exposure. So, you know, we start with 15 minutes and then we just try to add on and add on across a time. And now for us, we kind of found about 14 sauna exposures starts to really then drive the adaptations that we’re looking for. So it’s not a quick fix. You know, a heat acclimation strategy has to happen long before fight week or long before the fights. You know, this is a process that has to begin, you know, eight to 10 weeks before the fight so that we can actually get that adaptation and that tolerance to the stressor, to the exposure of heat.

Andrew Huberman (01:20:43):

This is interesting, until today, when we talked about this earlier and again now, I didn’t realize that, but it makes perfect sense now that I hear it, that heat adaptation is possible, that you’re basically can train the body to become better at cooling itself, which is what sweating is. I mean, I should have known that before, but you know, you don’t see that in the textbooks.

Duncan French (01:21:04):

And so, yeah, I mean, listen, it’s the same as the ketogenic conversation. You know, you’re training your body to be more metabolic efficient. You’re training your body to tolerate heat more. You’re training your body, like the body is, you know, as an organism, as an organic system, it’s hugely adaptable. It’s hugely plastic. But I think the skill is understanding the whens, the whys and the where ofs in terms of changing the overload, changing the stimulus to drive specific adaptation. And philosophically, that’s how we go about our work here. We talk about adaptation led programming. Now, adaptation led programming fits into every single category, not just lifting weights or running track. It fits into nutrition. It fits into sitting in the sauna. It fits into being in a cold bath or not. It fits into so many different things because we’re driven by scientific insights. And that’s how we really want to go about our business.

Andrew Huberman (01:21:59):

I love it. I love this concept of adaptation led programming and doing that, not just in the context of, you know, throwing another plate on the bar or something like that, but in every aspect of one’s training and performance. And I think there’s a lot here that’s applicable to the recreational athlete too. Yeah. Would you say that, you know, what comes to mind is 12 weeks. It feels like 12 weeks is a nice block of time for someone to try something in terms of to try something new, see how they adapt, adapt, and then maybe switch to something new. I realize that it’s very hard to throw a kind of pan timeframe around something, but in terms of if someone wanted to experiment with heat adaptation or experiment with cold adaptation or change up their training regimen or diet and look at metabolic efficiency, do you think 12 weeks is a good period of time to really give something a thorough go and gain an understanding of how well or how poorly something works for oneself? Or would you say eight is enough with three?

Duncan French (01:22:57):

I mean, that’s the how long is a piece of string kind of response, right? I mean, yes, if we’re just talking arbitrary numbers. Recreational experimenter, yeah. Three months exposure, 12 week training strategy, 12 week intervention is more than adequate to say for 99% of things that change within the body that physiologically adapt to a training stimulus or an overload stimulus, you’re going to start to see either regression or progression, beneficial or detrimental effects within three months. Absolutely, I would say so. Now, listen, I say that in as much as we do training blocks here that are three weeks long.

Andrew Huberman (01:23:34):

Right. That’s because of this constraint that sometimes people suddenly have to, they get the call to fight.

Duncan French (01:23:39):

Correct, yeah, so it’s like super condensed. And in that scenario, we’re always conscious of is their body or this individual, do they have the ability to tolerate that super overload, that like super condensed exposure? Now, we might be doing that purposefully. We might be trying to do an overreaching strategy where we’re really trying to damage or flex something. And I don’t mean like negatively damaged, but like we’re trying to damage tissue to really get an adaptive response versus a more drawn out 12 week strategy, which is more coherent, more planned out, more structured in nature. But yeah, for all your listeners, I would say if 12 weeks to engage in a process of trying to change and adapt your body or expose yourself to something is more than sufficient to see if it’s gonna be the right approach for you. And I think the individual interpretation is always has to be considered. And I think that’s where it comes back to be a thinking man’s athlete or be a thinking man’s trainer, like someone that’s going through exercise.


You have to consciously understand where your body’s at any moment in time. You know, you’ve got to be real with yourself. You can create a journal, create a log of your training, create a log of your feelings, your subjective feedback of how you felt, your mood, your sleep.

Andrew Huberman (01:24:59):

Your athletes do that? Yeah.

Duncan French (01:25:01):

We try to promote that because again, that’s part of this process, you know. It might be 12 weeks for you, but I might get the same responses in eight weeks, you know. And I think that’s another critical theme here is that, you know, we could put 15 guys on the mat and give them the same workout.


And there’s gonna be 15 different responses to that same workout because the human organism is so complex and in nature that it’s gonna adapt differently, you know. Some people will tolerate it. Some people are gonna be challenged by it. Some people have got a metabolic makeup that’s gonna promote it. Some people are metabolically challenged by it. You know, there’s just so many different things that we have to consider. And that’s what we try to do here. It’s the cross we bear is that we try to understand on an individual level how to optimize athletic performance.

Andrew Huberman (01:25:53):

I think it’s terrific. And, you know, the athletes here are so fortunate to have this and most people out there, you know, I’ve certainly been trying to encourage people to learn some science and some mechanism and become scientists of their own pursuits, whether or not skill learning or athletic pursuit, et cetera. As a sort of a final question, what are some things about the UFC or something about the UFC that perhaps people don’t know in terms of its overall mission or what you guys are trying to do here? I mean, I think I’ve become a fan of MMA and I am more and more as time moves on. Some people might be in MMA, some people not into watching MMA, but what are some things that the UFC is interested in and doing that most people might not know about and certainly I might not know about?

Duncan French (01:26:38):

Yeah, I mean, I think, you know, we try to be cutting edge. We try to be super progressive. You know, we think we’ve got an amazing platform here, particularly at the Performance Institute to do some really cool things that can inform many different people. And that doesn’t just mean the 600 or so athletes that are on our global roster. What we’re trying to do is influence, you know, global community around optimizing human performance. So, you know, any moment in time, we’re engaging in different technologies with different vendors, different partners, you know, exploring opportunities to, you know, learn more, share data, understand what’s the best mechanisms for, you know, interpreting your body, interpreting how your body’s responding to training, interpreting, you know, your nutrition or whatever it may be. We get, we’re in a really privileged position to do that. But we’ve also, you know, hence you’ve been here today, you know, we’re also trying to venture into some really cool areas of science and research that’s got applicability that you can take from high-performance athletes and apply, you know, to yourself, to, you know, Joe Blow walking down the street, you know, out there that is really interesting. And that’s everything from, you know, whether it’s CBD and psychedelics through to different technologies for, you know, thermal monitoring and Bluetooth heart rate monitoring or whatever it may be through to data management, et cetera, and anything in between. We’ve got some great partners on the nutrition side, on the psychology side, on the data side. And I think, you know, we always try to just push the envelope a little bit more. I think we keep our core mission with our athletes, but I think a lot of what we do hence your podcast and, you know, like an amazing platform, you do such a great job of it, that, you know, we can all learn and take from, you know, the elite and interpret how it might help us and just in the general population. So I think that’s, you know, that’s our North Star is to provide our athletes the best integrated service of care. But we also want to influence, you know, just the global community and put, you know, the UFC at the forefront of that. That’s great. Well, you guys are certainly doing it.

Andrew Huberman (01:28:43):

We can’t let the cat out of the bag just yet, but the things that we’re gearing up to do with my laboratory and the work together, hopefully we’ll be able to talk about that and share that in the year to come. But that’s, we’re very excited about that. And Duncan, look, you know, I have this filter that I use when I talk to people, academics or otherwise, which is, you know, some people, they open their mouth and they’re like, you know, some people they open their mouth and it doesn’t make much difference, but when you speak, I learn so much. I’m going to take the protocols that I’ve heard about today. I’m going to think about how I’m training and how I could train differently and better, how I’m eating, how I could eat differently and better for sake of performance and just in general.


Thank you so much for your time, your scientific expertise, the stuff you’re doing in the practical realm, it’s immense. So hopefully we can do it again.

Duncan French (01:29:38):

Yes, thank you, this has been a blast. I appreciate it and yeah, keep doing what you’re doing because I know there’s a lot of people out there that love the platform. So thanks for the invite, it’s been awesome.

Andrew Huberman (01:29:46):

Thank you, thanks so much. Thank you for joining me for my conversation with Dr. Duncan French. I hope you found it as insightful and informative as I did. If you’re enjoying this podcast and or learning from it, please subscribe to our YouTube channel. Please also leave us a comment or a suggestion of a future topic or future guests that you’d like us to have on the Huberman Lab Podcast. In addition, please subscribe to our podcast on Apple and Spotify. And on Apple, you can leave us up to a five-star review.


Please also check out the sponsors that we mentioned at the beginning of this episode. That’s a terrific way to support this podcast. And as mentioned at the beginning of today’s episode, we are now partnered with Momentous Supplements because they make single ingredient formulations that are of the absolute highest quality and they ship international. If you go to slash Huberman, you will find many of the supplements that have been discussed on various episodes of the Huberman Lab Podcast, and you will find various protocols related to those supplements. I’d also like to mention that if you’re not already following us on Instagram at Huberman Lab, you might want to do so there. I do brief science tutorials and offer science-based protocols for all sorts of things that are often separate from the protocols and information covered on the Huberman Lab Podcast. We’re also on Twitter as Huberman Lab.


And last and certainly not least, thank you for your interest in science. I’ll see you in the next one.


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Episode Info

In this episode, I talk to Dr. Duncan French, Ph.D., the Vice President of Performance at the UFC Performance Institute and a world-class performance specialist. We discuss specific resistance (weight) training regimens for increasing testosterone in men and women and how to vary mechanical loads and rest between sets and workouts to optimize hormone output and training results. We also discuss how stress-induced "catecholamines" can increase testosterone or decrease it, depending on duration and mindset. And we discuss specific cold- and heat- therapies for increasing resilience, reducing inflammation, heat shock proteins and more. We discuss nutrition for training and how to match nutrition to training goals and metabolic flexibility. We discuss mental focus and how long to train for skill development. Finally, we discuss how mixed martial arts and the UFC Performance Institute are a template for exploring human performance more generally. This episode is intended for anyone interested in athletic and mental performance: athletes, students, and recreational exercisers and includes both science and many practical tools people can apply in their own training. 

Thank you to our sponsors

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For the full show notes, visit


(00:00:00) Dr. Duncan French 

(00:02:27) Sponsors

(00:05:44) Duncan’s Background in Exercise Science

(00:11:45) How Certain Exercises Increase Testosterone

(00:16:22) What Kind of Training Increases Testosterone & Growth Hormone?

(00:20:19) Intensity: Mechanical Load; Volume: Metabolic Load; Inter-set Rest Periods

(00:25:25) Training Frequency & Combining Workout Goals  

(00:29:35) How Stress Can Increase or Decrease Testosterone 

(00:36:55) Using Cold Exposure for Mindset, Anti-Inflammation, Muscle-Growth

(00:46:55) Skill Development

(00:50:05) Why Hard Exercise Creates Brain Fog: Role of Nutrition 

(00:53:55) Low-Carbohydrate Versus All-Macronutrient Diets on Performance

(00:56:15) Ketones & Brain Energy, Offsetting Brain Injury; Spiking Glucose During Ketosis

(00:59:13) Metabolic Efficiency, Matching Nutrition to Training, “Needs Based Eating”

(01:05:00) Duncan’s Work with Olympic Athletes, NCAA, UFC (Ultimate Fighting Championship)

(01:08:00) Why UFC & MMA (Mixed-Martial Arts) Are So Valuable for Advancing Performance

(01:12:40) Voluntarily Switching Between Different States of Arousal

(01:14:30) Heat, Getting Better at Sweating, Heat Shock Proteins, Sauna

(01:20:12) Using Rotating 12-Week Training Programs; Logging Objective & Subjective Data

(01:24:07) Surprising & Unknown Aspects of The UFC and UFC Performance Institute

(01:27:45) Conclusions, Zero-Cost Support, Sponsors, Supplements, Instagram

Title Card Photo Credit: Mike Blabac


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