Stress and Resiliency: Understanding Cortisol (Performance & Longevity Series)

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Transcript: Stress and Resiliency: Understanding Cortisol (Performance & Longevity Series)

Season 11, Episode 8  | August 21, 2025

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Welcome to Life Time Talks in our series on performance and longevity with MIORA. I’m Jamie Martin, and I’m here with Life Time’s chief science officer, Jim LaValle. And today, we are talking about stress and resiliency, specifically understanding cortisol, that stress hormone that’s essential, actually, for energy and health. Yet when levels of cortisol get to be too high, things can get out of balance. So in this episode, we’re going to talk about what we can do to bring cortisol into balance and create a more resilient body. Jim?

Yes.

Are you feeling stressed or at ease right now as we kick off this episode?

I don’t know. My heart rate’s at about 54, so I think I’m doing good.

That’s awesome. Love it. I love it. OK. So we’re going to dive in. So I referred to cortisol as the stress hormone. What is it exactly, and how does it influence our health?

Well, we’re talking about my favorite topic. So cortisol is made in your adrenal glands, and it is made in response to stress. So we have two kinds of stress. We have acute stress and chronic stress.
And we have a primitive nervous system in a modern world. So what we interpret as stress now — traffic jams, late for deadlines, working long hours, whatever the reason — our body still thinks that a white tiger is chasing us. Maybe a little less than a real white tiger chasing us. But our neurohormonal signals that come from the brain, specifically the hypothalamus, the pituitary then signals the adrenal glands to release cortisol.

We need cortisol. Cortisol is good. We’re supposed to make a lot of it in the morning. So we have something called the cortisol awakening response, where we raise our cortisol in the morning to prepare ourselves for the day. And then throughout the day, it’s supposed to drop.

And literally, as we move through our day, it should drop to nearly zero at night, which then signals the release of another important hormone that’s tied directly to cortisol, melatonin, which helps us to sleep. So cortisol is what drives a part of our metabolism, and it drives energy production. But it doesn’t do that alone.

So tell me more about that.

Yeah. So it’s important to understand that cortisol is in a perpetual relationship with insulin and thyroid hormone. So together, the three of those will dictate whether or not you’ve got great energy throughout your day, you’re feeling resilient, or you’re getting that midday crash in energy — you’re feeling fatigued, you’re not sleeping well, and you’re putting on the pounds. So cortisol is a central player in our health and our metabolism.

OK. So we think about cortisol. We think about it the stress hormone. Many, when they hear it, they think it’s bad. But we’ve talked about it. It is essential. So what are some frequent misconceptions about cortisol that we want to make sure that we just debunk right now as we’re getting started on this topic?

Yeah. So first of all, cortisol is not bad or good. The appropriate release of cortisol is really good for us. When it gets out of kilter, so you lose what’s called your cortisol curve. So your diurnal pattern. So all your body’s hormones are being released in a pattern. And that release is controlled by something called — I’m going to use a big word — the suprachiasmatic nucleus.

I’ve heard of this one before. It’s tied to our, let’s say, circadian rhythms, right?

Exactly. So the suprachiasmatic nucleus is known as the master slave clock. It’s dictating all the other hormone signals of what’s being released through the course of the day. Cortisol is one of the big things that can disrupt the suprachiasmatic nucleus. And now we’re out of kilter with how and how much we’re delivering sex hormones, what is our insulin response from our beta cells of our pancreas, in addition to gut health and gut hormone release.

So cortisol is a central figure in how our metabolism functions. And the more it gets disrupted, the more it moves us towards a path of chronic conditions. A lot of times, people think, oh, I’m not stressed, because they don’t need Medicaid. Then that’s the first weak link. That’s where we don’t want to go.

But it’s important to realize that, since the beginning of recorded medical history, the most valuable herb in every culture, since it’s been recorded thousands of years, has been the herb that helps people with stress. So that tells you how important even ancient civilization thought about being resilient to the impact, or what I would say the negative impact, of too much cortisol. Now, the other thing to keep in mind is you can get to the point where you don’t make enough.

So then what?

So then that’s when you run into some — these are more big chronic problems where you lose your cortisol awakening response. You’re not making enough in the morning. I don’t know. There may be a couple people listening that go, I don’t function without the first three cups of coffee.

Yep, absolutely.

And then it also can create where you have a low awakening response. And because of that, and you’re just pushing all day and releasing that cortisol, losing that cortisol curve — it’s called flattening of the cortisol curve — you end up with something called nocturnal hypercortisolism. I make too much at night.

What is that?

So your opposite of what you should be doing, right?

You’re exactly opposite.

Flipping it upside down.

And what that ends up doing is creating sleep disturbances because insomnia is a disorder of hyperarousal, meaning your brain takes on too much stress. You respond with too much cortisol throughout the course of your day. And when you go to go to sleep at night, your brain is convinced there’s a white tiger in the room.

Yeah. So there’s no way you’re falling asleep then.

You either fall asleep and you wake up at 3:00 AM thinking about the next day event, or you can’t even get to sleep. So cortisol is a really important piece of the puzzle for longevity and performance health.
Absolutely. How would somebody know when their cortisol is in balance versus out of balance? What is that — I mean, you mentioned a couple of things like you’re not falling asleep at night. There’s going to be some indicators. But what else in terms of balance versus imbalance?

I mean, a big one — craving for comfort foods.

We’ve talked about that a little bit on this podcast.

Yeah. So when all of a sudden you get home from work, and the first thing you’re doing is rooting around for, is there a cookie? Is there a row of cookies?

You can’t just leave one.

No, you don’t want to leave one. And I don’t like even numbers, so I can’t eat one. I’ve got to eat three. Or it could also be you’re thinking foggy. So cognitive issues relate to that stress response.

You could even be experiencing joint aches and pains because when you create a lot of cortisol, you start triggering a lot of inflammatory cytokines, which then can lead to feeling joint aches, muscle pains, those kind of things, poor recovery from exercise. And then you could also have more frequent colds and flus during chronic stress. And, in fact, we know that people with diabetes, when they get under stress, their blood sugars go up. If you’re wearing a CGM, Continuous Glucose Monitor, you may notice, oh wow, I had a super stressful day, and my blood sugars were going higher than what I thought they should have been for what I ate. So those are issues.

Another one is gut permeability changes. And how that happens is that — and you can do this even with just training. So the harder you train, the more your cortisol response will occur. And so if you do that in a sustained way, you make more of an inflammatory compound called interleukin 6, IL-6. IL-6 goes to the gut because you have a nervous system that connects the brain to the gut, called the enteric nervous system.

So when your stress hormones go up, first of all, you directly release more cortisol, which makes your gut more permeable. But more importantly, you release something called corticotropin-releasing hormone. It’s — hey, release more cortisol. Don’t you realize we’re under stress?

That contributes to your gut getting more permeable because what happens is the IL-6 sends a signal to the epithelial cells, the lining of your intestine. It’s only one cell layer thick. And you have these little gates between those cells called tight junctions.

And the IL-6 signals the gates to open. And when that happens, now bacteria can get through into the bloodstream. You can maybe not have digested your food well. And peptides from the proteins get through.

And now you have something called antigen-presenting cells. You’ve got these cells I’m presenting an allergen to you. And so you used to tolerate eating wheat, but now you’re not.

All of a sudden, you’re having a reaction.

Yeah. And why am I having this reaction? Well, more than likely, you’ve got gut permeability changes. And then your immune system gets triggering that antigen antibody response and an inflammatory response, which then also goes back to the brain. Triggers more inflammatory signaling. And now all of a sudden, you’re in this chronic cortisol state.

OK. So what I’m hearing is health effects. When cortisol is out of balance, it can affect gut health, immune health, cognition — your brain health as well. What about cardiovascular health or other places where it effects?

Sure. I mean, just to continue on the story, so the immune system being big because even things like risk for developing things like cancer, your immune system, you get less able to make functional natural killer cells and T killer cells. So now you get a cold and flu. Now you might make cancer cells, and your body is supposed to patrol that and knock them out because we’re always making one no matter who you are, and you want to knock them out.

Cardiovascular disease is one of the big ones because when your cortisol goes high, you make more adrenaline and more noradrenaline. And that stiffens and tightens your arteries to where they’re not able to respond to variations in your stress so that what happens when your blood vessels are stiff, your heart’s got to pump harder —

It has to work harder. We make it work harder.

— to get that blood through those vessels that are smaller. And that’s what raises your blood pressure.
And then in addition to that, obviously, when your cortisol is high, and you’re making more inflammatory chemicals in your body, that’s what starts to create the problems of plaque in your arteries, creating a change in something called intimal medial thickness — how the inner lining of the artery is behaving. So all of that comes into play with elevations in cortisol. And it’s not just the elevation in cortisol. It’s if you flatten your cortisol curve.

And that means it’s being released over time versus following that diurnal pattern that we’ve talked about.
Exactly. And, in fact, the risks on that — there was a big study, and there’s been some other subsequent studies that would support this, that your cardiometabolic risk goes up 333%. Your neurologic disorder risk goes up. And your mood disorders — the risk for depression, anxiety, other disturbances also go up.
So it’s really important to understand diurnal pattern and also that inverse pattern, that nocturnal hypercortisolism, because what happens is everybody goes, oh, I’m having trouble sleeping. I’m going to take something for my sleep. When do you take it? At bedtime. Well, what are you doing all day long to reduce your stress response?

Yeah, versus that reaction right before bedtime to do something. There are things we can do throughout the day to support that cortisol curve, right?

Yes, exactly.

OK, we’re going to get into that. But I have a couple other things that I want to make sure we dive into because I’ve heard these phrases known as cortisol belly or cortisol nose. What is that about?
Sure. So cortisol belly is — you just have to remember when cortisol goes up, glucose goes up. Insulin goes up. Thyroid hormone T4 gets converted to the active thyroid hormone T3, which is what drives your metabolism. So when cortisol goes up, you become more insulin-resistant. Your metabolism goes down.
Now I’m not burning fat, and I’m doing a great job at storing it. And you store it more as white fat, not brown fat. Why is that important? Brown fat burns. White fat doesn’t. So we get more visceral fat. So that’s cortisol belly. And actually, it was involved in a lot of the original research. 20 years ago, I was writing on that and actually doing research in that area. So I’ve been at that for a minute.

Yep. And just to clarify, because I know if you listen to past episodes, we’ve talked about how the visceral fat is metabolically active fat. So we want to just make sure you go back and listen to some of our previous episodes because you’ll hear more on that in-depth.

Absolutely. And then the cortisol nose is when you start to get broken, blood vessels. And a lot of that has to do with the fact that when you get under a lot of adrenaline, noradrenaline, you reduce that blood flow, actually, to your nose and nasal tissues. One, you could get a nosebleed, actually.

And then that reduced blood vessel integrity ends up creating damage to your blood vessels. And just like you’ll see that with people who are alcoholics — they’ll have those broken vessels — you can get those broken vessels by being under chronic stress because of the lack of blood vessel pliability. If you want to think about pliability, here’s how I try to explain it because I think it’s important to understand.

You get a garden hose. You go to the store, you buy a garden hose. And you got a garden hose reel hooked onto your house. And you hook up the hose, and it’s nice and flexible, and you roll it up, and it rolls on it really nice, but then you’re not so happy with the hose after a couple of years.

You lay it out. It’s laying in the sun. Maybe you run it over with the car a couple times. Just like what we do with our health. Hey, we’re not eating as well as we should, not exercising. The hose starts to get kinks in it.

And now you go to roll the hose up, and it gets kinked, and it’s not going back on the reel easy. If you think of a garden hose as your blood vessels, your blood vessels need to be pliable and flexible to meet the demands of varying blood pressure if you’re sitting, standing, working out, being at rest, whatever that is. As we’ve talked about before, heart rate variability, resting blood pressure. What’s your heart rate?
So when the more damage that we start to create — and cortisol is one of the biggest things when it’s unopposed, or you get into that diurnal pattern loss, that’s what damages our tissues and, in particular, our vasculature. So it’s actually pretty amazing how important it is and how vital it is for us but then how destructive it can be.

So now what do we do about it? Because I know we’ve talked a lot. There’s all sorts of lifestyle factors, but there are also, I’m assuming, tests and blood things that can identify, hey, you’ve got a lot of cortisol going through your body. We’ve talked about salivary tests. Tell us a little bit about — how do I know that I’m dealing with chronic stress or my cortisol levels are out of rhythm?

So we went through the symptoms. Remember, midday crash in energy, feeling overcommitted, feeling anxious, feeling stressed, maybe the craving patterns. And when it’s really bad, it’s when you eat past being full in order to fulfill an emotional need.

Yes.

That’s called the reward deficiency cascade. And so those are some of the — and yes, I’m tired. Yes, I’m gaining weight. I’m cognitively foggy. My blood pressure is slightly elevated. So that’s why you want to do those morning and night blood pressures every once in a while. At least do them once a month. Stay on top of that.

And then we get into — well, what kind of lab tests? So the most central lab test for the average person is look at your morning serum cortisol. And there’s an ideal range. If it’s too high, meaning you’re at the upper limits of normal cortisol, or if it’s too low, well, that tells you that, well, I’ve either losing my cortisol awakening response, or my awakening response is too dramatic. And a lot of times, that can be caused by the fact that you’re not sleeping restfully, and you’re not repairing your nervous system because of your sleep disturbance.

Yep. So if we’re not sleeping well —

Big problem.

OK. We’re going to — that’s a whole other episode —

That is a whole other episode.

— that we’re going to get into. OK.

Right. So right away, you can think of cortisol, a morning serum draw. And then we like to look at DHEA sulfate with it because DHEA is the building block for all your hormones, your sex hormones, and for cortisol.

Got it.

And DHEA is important to protect your brain from the memory issues. So when your cortisol gets high, what happens is you start to — it’s called dendritic retraction. The neurons go, whoop, I don’t want any of that cortisol. Don’t burn me. Don’t damage. Too much excitement here.

And then DHEA protects the hippocampus and protects against that inflammatory response which will actually swell the hippocampus. So you’ll see a lot of times people will have relatively high DHEA when they’re under a lot of stress. And that’s a healthy thing because they’ve protected their brain. When your DHEA goes low, though, that’s where it becomes a problem.

So cortisol DHEA is the main thing you’ll look in a morning serum. Now, you mentioned salivary or urinary hormone testing for cortisol. So there’s a couple of things that are different there. So a salivary cortisol pattern, you’ll spit in a tube four times during the day. And you’re looking for that diurnal pattern. So what is my cortisol in saliva in the morning, at noon, at evening, and then at bedtime?

And then with a — and similarly, with a urinary cortisol, what you’ll look at is the same pattern. What is my awakening cortisol response, and how’s it going during the day? But you can also look at how much cortisol has been metabolized to cortisone. So if you’ve got a big bucket of cortisol, and your cortisone levels are high, you are really pumping out a lot of cortisol.

So all these tests have value, typically. The urinary or salivary cortisols are actually advanced testing that we look into if, hey, we can’t figure out what’s going on with the morning serum. But that is the patterns that you’re looking for because it’s really important to understand that if that pattern gets thrown off, you are absolutely pushing yourself towards some sort of chronic illness.
OK, so I’m going to go back to the question is, what do we do about it? Because there’s so — how do you manage chronic stress? I mean, we know. We’ve talked in other episodes. There’s some very basic things — deep breathing, those pieces.

But what about a therapeutic approach? Let’s say you’re working with somebody who is — they have chronic stress. They’ve got other things going on in their life. Where do you start with somebody to get them really starting to prioritize this from a therapeutic approach?

Sure. Well, I mean, first of all, we could address sleep. And there’s a lot of techniques you can do for sleep. Do you want to mist lavender oil in your bedroom? Do you want to take an Epsom salt bath before you go to bed? Do want to not put your phone in the room and listen for a —

We’re all guilty of this. That’s just me going guilty.

Just put it on silent at least.

It is on sleep mode.

And it is good to wake up in the morning and get sun in your eyes to activate that suprachiasmatic nucleus or the master slave clock. That’s really good. And then it starts to depend on where you’re at. Say you’re very busy, but you’re not experiencing anything. Hey, I’m just busy.

But you’re not stressed. You’re not making lists. You’re not crashing midday. You’re not noticing fatigue. That’s where the value of that ancient wisdom of all those medical texts in every culture — take an adaptogen.

So that herb you’re talking about, right? OK, let’s go back to it.

Several of those. I mean, it depends on what culture you’re in, but whether it’s Siberian ginseng or it’s Manchurian from China ginseng or it’s eurycoma parviflora from — if you want to look at that, so that’s an interesting — Thai ginseng. There’s American ginseng. There’s a lot of — rhodiola is another one. Ashwagandha is another famous one.

So you could think about, hey, I want to take an adaptogen to keep me strong. I want to stay strong because I know I’m pushing hard, but I want to make sure that my brain stays in what’s called allostasis. So allostasis is the appropriate response to stress, and your brain sends the right signals out, and the suprachiasmatic nucleus or the master slave clock is happy, and everything is in sync.

When we start to get into problems with I’m feeling overcommitted during the day, I’m starting to feel anxious, I’m noticing food cravings, that’s where I like people to use natural compounds that can help them to feel more calm and overcome that issue. And, in fact, as soon as somebody tells me they’re having trouble with sleep, I’m always recommending — maybe you should take something during the day to keep your nervous system more calm, not feel sedated, but to keep your nervous system more calm so that you can lead into the night. And maybe you need to use melatonin and magnesium and other compounds.

Honokiol — I can give you a list a mile long on what you can do. But you may need to do those at bedtime. But the problem we’ve run into in our culture is we run until we break. And that results in one of the biggest categories of medicine used in our country — anti-anxiety drugs and antidepressants.

And our goal should really be is how do we keep our nervous system resilient so that we’re not wearing down the circuitry of our brain. And I like to tell people, it’s like a circuit breaker box. Your brain — and you know what happens when you put too much electricity through a circuit breaker box. The circuit blows.

And you can go into the living room and try to turn on that light all you want. You can check for the plug and see if it’s plugged in. But if the juice isn’t flowing through that circuit, nothing is going to bring light to that room. And that’s how your brain works.

And so I think it’s important that people understand the more you can be proactive about managing your stress response, the healthier you’re going to be in the long run because nobody likes to have a bad night’s sleep. No one wants to feel nervous and anxious and overcommitted and having energy crashes midday, the dreaded 1:00 to 3:00 PM crash. I always call it — remember there was Twelve O’Clock High, the movie Twelve O’Clock High? I call cortisol problems the 12 o’clock low.

Oh. Well, that would make sense because there’s that window that you hear a lot of people talk. That’s a hard part of the day for a lot of people to get through. They’re crashing.

I hear a lot of executives that I’ve worked with over the years. They’ll just say, I don’t even like to make a decision in mid-afternoon. I’ll try to make my critical decisions in the morning because, in the afternoon, I’m cognitively not thinking clearly. I feel like I’m pushing a thought through Jell-O. I’m starting to have this nod-off effect. And those are big, big issues.

And so using things like theanine, which is an extract from green tea that actually blocks glutamate, and, therefore, blocking your glutamate, which is an excitatory neurochemical your brain makes, it helps to raise your GABA level, which is more inhibitory. So you feel calmer and less excitable and don’t want to make a list for your list. Right?

I just love that the list for your list, it’s like, oh, I know so many people who would relate to that, and at times myself, yeah.

I’m the same. I mean, modern living, we’re fast-paced.

Absolutely.
We have to remember stuff. So then if that is more based on, hey, I’m craving in the afternoon, and I’m nervous, and I have stress-related weight gain, the herb compound known as Relora has got claims that are allowed to say — effective to help stress-related weight gain. And it helps to reduce that craving for comfort food or what we know as, now everybody’s talking about it, food noise.

Yes.

And so you can talk to people about, for example, weight loss. I mean, I’ve interviewed tens of thousands of people at this point in my career on weight loss, and I’ve overseen lots of charts regarding that — is that people will say, you know what, I do exactly what my clinician told me or my trainer told me until 4 o’clock.

And then everything just — all the good habits are gone at that point.

It falls apart. I’m picking at my kid’s plate. I’m eating a few cookies, and I’m eating a few chips. Now I’m getting into the ice cream. Before you know it, I look at my night, and I just ate all my calories at night.
And there’s actually — I remember when this first came out, they called it night eating syndrome because when we don’t understand why it happened, we call it a syndrome, right?

Yeah, exactly.

Now, that term was from 25 years ago. And a lot of my research on cortisol started 25, 30 years ago and looking at that. And so it’s really interesting because we just don’t appreciate the effect of stress hormones on us, and many times until it breaks.

Until we break.

Yeah. And you can do this through even training. So we always like to hear that term — you never overtrain. You just under-recover. Well, both are true. You can’t overtrain.

And you can’t under-recover.

And you can’t under-recover. It’s not one or the other. And so you could even be slender. This isn’t just about people gaining weight. You could be very slender. You could be an endurance athlete.
And you notice, oh, I’m losing lean body mass because one of the things that happens with cortisol is you get catabolic. And you also can start to leach minerals from the bone. And you can literally start to get stress fractures, get osteopenic from this effect.

And so it’s really important. Measure your cortisol. Find out where you’re at because even if you’re not feeling it yet, but you’re a high-performance person, high achiever, high performance, get a lot done, you want to make sure you’re managing that so that it doesn’t start to trickle down into a problem where you notice either changes in your body, changes in your sleep, or more importantly, changes in your mental health.

And so, again, and if you’ve been listening to this series for any amount of time, you’re finding the interconnectedness with the topics we’re talking about. I mean, we know that when it comes to stress management, there’s so many things lifestyle-wise we can do — should manage that sleep, exercise, movement, connections with community. Anything else that you would recommend for people in that space before we wrap up this episode?

Well, the first thing is find purpose in your life. And I think the biggest purpose is that we experience joy, and we experience love, and we have that sense of community. It’s no surprise that people in long-lived societies like the Sardinians or Icarus, Greece, or Okinawa, Japan, Loma Linda, California, is that there’s a real sense, as people are aging, of belonging and managing stress. They have a meaningful lunch.

They sit down and eat.

They’re not rushing through everything, one thing right to the other. Yeah.

And the other piece to understand is, typically, look, plenty of studies have shown this. After a 10-hour workday, most people’s productivity goes way down. Something I had to learn.

Nowadays, unless it’s something incredibly important, my work meter is turned off at 7:00 PM no matter what, typically, 6:00 PM, because I’ve recognized that, in my off time, I actually can end up problem-solving just by letting things go and having a fresher mind for the next day. So find ways to reduce that stress to get a restful night’s sleep. I think that’s super important.

Understand the relationship between cortisol, insulin, thyroid hormone, gut health, and then the term “allostasis” and “allostatic load,” when you have so much stress that now your brain’s circuit board is now sending the wrong signals to the rest of the body. And if you can start to grasp that, you can understand the impact of stress in your life and then take steps to create countermeasures so that you can enjoy life.
Absolutely. And we have tons of resources on this at miora.lifetime.life, experiencelife.lifetime.life. Tons of content that can help you figure out how do I manage my stress, what are the right ways for me to do it because we’re not all the same. We have different things. And the other thing I will just add is let’s put our devices down in the evening too because I know we’re in this constantly connected world.

I need to take this off at night.

Right. Even though it could give you data, it’s like, do we really need it?

Yeah. It’s OK. And by the way, look at our mindfulness program.

Yes.

Another important part of what we’re doing and take advantage of the sauna and everything else that you can do to bring that feeling of being overcommitted and stressed down.

Yep. All right. Jim, another episode full of great tidbits and information. Thank you for joining me.

Always good to be here.

We’ll be back. We’ll be back again.

All right.

Thanks, Jim.

Yes.

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