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The Science of Recovery: How to be More Resilient | Kristen Holmes

Episode 45, duration 1 hr 13 mins
Episode 45

The Science of Recovery: How to be More Resilient | Kristen Holmes

As Vice President of Performance Science at WHOOP, Kristen works with hundreds of the best tactical, professional, surgical teams, corporate, and NCAA Athlete Teams in the world, helping them interpret WHOOP data to optimize training, recovery, and sleep behavior. Kristen's research focuses on the temporal organization of circadian influences and their effect on physiological and psychological resilience. Kristen was a 3x All American, 2x Big 10 Athlete of the year at the University of Iowa, competing in both Field Hockey and Basketball, and a 2021 University of Iowa Hall of Fame Inductee. 7-year member of the U.S. National Field Hockey Team and one of the most successful coaches in Ivy League history, having won 12 league titles in 13 seasons and a National Championship at Princeton University. Kristen has an MIT Sloan Artificial Intelligence Certificate, M.A. Psychology, and Sports Performance, B.A., Political Science, University of Iowa, Ph.D. Candidate, University of Queensland.

In this episode we discuss:
– Is your circadian rhythm dysfunctional, and how can you fix it?
– How heat and cold exposure can improve your mental health
– What elite atheletes and performers all have in common.
– How to improve your resiliency and readiness.
– The one exercise you can do for longevity.

00:00:00 Introduction

00:03:12 Kristen’s History

00:11:00 Alignments in our Body

00:16:00 Top Behaviors for Circadian Alignment

00:23:00 Bedtime and Morning Times

00:27:00 Things you Should do During the Day

00:36:00 When Should You Eat?

00:44:00 Sleep vs. Exercise: Which One Is More Important?

00:47:00 Adaptability

00:51:00 Sex and Sleep

00:54:00 Heat vs. Cold

01:00:00 Training

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Kristen Holmes, Dr Lyon

Dr. Lyon (01:00:00 -> 01:00:31)

Kristen Holmes. Welcome to the podcast. I’m so excited to have you on. We, I just want to share a little bit about how we met actually. So we met on the triple seven expedition. They were doing a training jump and this is, this was like in the middle of Arizona, by the way, literally in the middle of Arizona in nowhere Arizona and the triple seven is the elite military operators. Seals were doing seven jumps in seven days on seven continents

Kristen Holmes (01:00:32 -> 01:00:33)

to raise money for folds of honor.

Dr. Lyon (01:00:33 -> 01:00:37)

Exactly. To raise money for Folds of Honor. And that’s where we met.

Kristen Holmes (01:00:38 -> 01:00:50)

I know it was uh it was so great. I mean, I, I was just fan girling you, you know, for ages. So the opportunity came about to, to be able to hang out with you in person. It was, it was pretty incredible.

Dr. Lyon (01:00:50 -> 01:01:21)

Well, I appreciate that, but the real fan girl moment is about to happen right now because I begged you to come on this podcast. You are a amazing resource for all things adaptation. And I would love for you to share a little bit about who you are, what you’re doing. And then I want to jump in before we go forward. I want to talk a little bit about your history because you are a very interesting mix of you’ve been a competitive athlete and then a coach and now a scientist. So,

Kristen Holmes (01:01:21 -> 01:04:37)

yeah. Um, gosh, so, yeah, as you said, I, I, I guess early career, I was a two sport athlete at the University of Iowa. I competed in field hockey was my main sport and I was competed in basketball and then went on to compete for the US national team. Um was actually competing in college at the same time for the US field hockey team, uh and spent about seven years, uh competing for the US, uh which was incredible and then simultaneously was getting experience coaching. So I coached the U 19 national team. Actually, I was, wasn’t too much older than them at the time. But, um, but got my, got my kind of uh get some experience in, in the coaching world and, and just loved it. I loved uh working with athletes. I loved, um you know, obviously the, the technical and tactical aspects of the sport, I just, uh you know, was adored. Um And, and I love trying to kind of solve these really kind of acute problems, um, you know, in, in kind of that environment. Um So I was coaching at the international level and then, uh got an opportunity to be the head coach at Princeton University. So I went on to coach at Princeton for 13 seasons and it was hockey. Yeah. And I was uh kind of in, in parallel teaching a seminar there. Um Aptly titled Performance Optimization uh which was great and it was just a mix of I had some student athletes but some students as well. Um So yeah, Princeton was really an incredible experience. Um And I was actually while I was at Princeton, I was building a technology. Um I was uh I had, I was using just fit api and pulling in their heart rate data and transforming it and, and really trying to uh understand this notion of readiness. So you mentioned adaptation, you know, I’ve always been really, really interested in, you know, how do we, you know, at the time obviously was coaching. So how do I, how do I set, what are the conditions that actually enable my athletes to show up with the necessary capacity to take on the load that I want to put on them that day? Um And, you know, with this technology that I built, I, I realized very quickly that the load I was putting on them in practice those two hours of training actually didn’t predict next day readiness. So I wasn’t necessarily able to use those data to inform how I train them tomorrow. So for those folks in kind of the coaching world know that that is what we’re always trying to understand you know, what kind of load, volume intensity can I put on my athlete to train them in a way that is gonna maximize their adaptation. So I realized kind of in the, in the data and over the course of years and years of training athletes that it’s the other 22 hours that they’re not with me, that is most predictive of um whether or not you’re gonna adapt in a functional way to previous day training load for sure, but life load. Um So it’s these other factors um you know, in, in training, it depends what phase of training you’re in, of course. But um you know, training plays AAA part, but it’s just a piece of the puzzle. So it’s what are these other factors that really are going to influence whether or not we can show up tomorrow for cap you know, with the right amount of capacity to, to operate in a way that feels really good.

Dr. Lyon (01:04:37 -> 01:04:48)

You must have had some really interesting aha moments that change the way that you live your life and also what you are doing now. So right now you are, why don’t you, why don’t you tell the listeners.

Kristen Holmes (01:04:48 -> 01:06:23)

I’m Vice president of Performance Science at a technology company called whoop uh W H 00 P. Uh We make a physiological monitoring device that is basically taking in, you know, at a very high sample rate, huge amounts of heart rate data. And then transforming that data to give you insight into how your body is responding and adapting to external stress. So we measure things like heart rate variability and resting heart rate. Uh sleep, we model that to give you a sense of how you’re adapting to load. Um We have a very deep dive into your sleep. So looking at your sleep architecture, um the time in bed, uh your consistent sleep consistency, how much sleep debt you’re you’re bringing on. Um And then we uh measure your strain, which is a kind of a summary statistic of your cardiovascular load that builds throughout the day uh in real time because you can see it and there’s lots of like coaching and um advice on the platform on, you know, how to improve the metrics that we say are important to track. Um Yeah. So I I basically in uh involved in the research side of things. So I do a little bit on the validation side. So working with external partners to really understand uh to really give a point of view on, you know, what are the behaviors that move around the metrics that we track? So if we say heart rate variability, for example, is a an important marker to pay attention to what are the, what are the behaviors that are going to? Um and you know, increase heart rate variability or decrease heart rate variability and, and increasing hearty variability is a sign that you’re adapting functionally to stress

Dr. Lyon (01:06:23 -> 01:06:24)

and what is heart rate variability?

Kristen Holmes (01:06:25 -> 01:06:40)

So hearty variability is a time interval between heartbeats and the more variability. Uh the healthier you are, the more responsive you are to um to your environment, you know, the more able you are to adapt to your environment in a functional way.

Dr. Lyon (01:06:42 -> 01:06:52)

And so you’re able to measure these outcomes based on the input that an individual is doing in not just training but in the other 22 hours of their life.

Kristen Holmes (01:06:52 -> 01:07:36)

Exactly. Yeah. And you know, we have obviously a very rich data set that we can pull a lot of these data from. So we can go in and retrospectively look at our data set and, and and ask some of these questions, but where my kind of job is a little bit different, we do retrospective analysis, but we do a lot of perspective studies. So we’re trying to isolate effects. So for example, what does time restricted eating have on next day recovery? And how does it impact sleep? How does it impact your training capacity? Um Your, your mental health. Um You know, these are questions that um we try to ask of our data but are, you know, try to do in this perspective, kind of research are able to get surveys and um have kind of qualitative data that helps us contextualize. Um Yeah, those, those data

Dr. Lyon (01:07:36 -> 01:07:38)

and what are some of the buckets that you look at?

Kristen Holmes (01:07:39 -> 01:08:48)

Yeah. So um so circadian um is, is one of the, the big buckets and, and a, a massive focus focus of my research. Um So we’re really looking at um and when people think about circadian, it’s basically, um you know, the environment is giving our body clock. So we want to be able to anticipate what’s happening in the environment. And that’s really what our circadian rhythms help us do. And in terms of what’s happening in the environment that our body is anticipating and trying to respond to are things like eating and exercise and activity. Um And, you know, light is a huge influencer on our circadian rhythms. Um So, you know, when we’re viewing light and when we’re not viewing a light is going to impact our alertness and our sleepiness. Um And we wanna make sure that um all of those um external inputs are aligned with our endogenous preferences. So we have these preferences um that our body wants to, to do and when there’s a misalignment between what we actually do and what our endogenous preferences are, that’s a term called misalignments.

Dr. Lyon (01:08:48 -> 01:08:56)

Can you say that again? I think that that’s a super critical point and probably at the focal point of circuiting biology.

Kristen Holmes (01:08:56 -> 01:10:00)

So I think people underestimate how important it is to ensure that there’s alignment between our endogenous preferences and what is happening in our daily life. So we have basically an active phase of our circadian rhythm and an inactive phase of our circadian rhythm. So things that should be happening during the active phase of our circadian rhythm is we should be viewing a lot of light, we should be exercising, we should be eating. Um And then there’s this inactive phase of our circadian rhythm, which is, you know, basically, once the sun goes down, we want to not eat, we wanna be, you know, kind of start to ramp down our social activity, ramp down our activity levels. Generally, we want to restrict our light viewing. So when we don’t, when we are doing things during our interactive phase, that should be happening during our active phase, our body, all sorts of deleterious things happen, um and have severe repercussions mentally and physically if these are kind of, if you’re chronically misaligned, um this is gonna wreak habit havoc on your system

Dr. Lyon (01:10:01 -> 01:10:17)

And when you talk about circadian alignment, circadian circuiting clock is a 24 o’clock? And the active phase of the circadian timing for a non nocturnal mammal with such a human,

Kristen Holmes (01:10:17 -> 01:10:18)

it would

Dr. Lyon (01:10:18 -> 01:10:25)

be, uh eating, I don’t know, exercising all the things you said also, probably mental activity

Kristen Holmes (01:10:26 -> 01:10:49)

Yeah. Yeah. We’re gonna be way more primed to focus during the active phase of our circadian rhythm. So that’s basically once the sun goes up, once the sun goes down, that’s when cognitively we’re going to be primed. Um And that’s when we’re gonna be metabolically, you know, most efficient to, you know, we, and, and biasing toward earlier part of the circadian rhythm, like earlier part of the day, we want to try to take on a bulk of our calories.

Dr. Lyon (01:10:49 -> 01:11:00)


Yeah. I think that this also just sets up, um, a big picture concept is that when the sun goes down, we should be shutting down essentially if we were to truly live in alignment with these

Kristen Holmes (01:11:00 -> 01:11:02)

endogenous perferences

Dr. Lyon (01:11:02 -> 01:11:20)

nobody does that. And I’m not even just talking about food, I’m talking about, you know, doing work at night, even if it is not on a computer, it’s still reading, it’s still very active and we live in an environment that throws us out of any kind of circadian alignment.

Kristen Holmes (01:11:20 -> 01:11:39)

We, we really do. And, you know, it’s, it’s a, you know, we haven’t adapted to blue light, you know, as a species. So I think that’s really important to, to recognize, you know, we’re, we’re looking at blue light from our devices, you know, certainly after the sun goes down, you know, I’ve seen filters help and black and glasses help

Dr. Lyon (01:11:39 -> 01:11:42)

Do you know what adaptation would look like for a human to blue light.

Kristen Holmes (01:11:43 -> 01:14:43)

I don’t know. I don’t know. And I, I don’t know if that’s been investigated. Um, you know, what would be required. Um, you know, but I can tell you that it’s not going to happen during our lifetime. I know, which is, which is a bummer. But I mean, if you think about, you know, 20% of the labor force are shift workers. That’s 600 million people are working outside the hours of, of seven of, you know, basically seven AM and six PM. Right? If we think about that’s our time point of like when we want to be active and, and we know shift workers obviously, um you know, they, they, you know, I hate to say it because I, I, you know, it’s, it’s, but cancer, cancer proneness and um and obesity and yeah, and, and glucose metabolic disregulation. So it’s, it’s, it’s sad. But um that said, you know, the focus of my work is, is actually in these high stakes high stress environments. So I, I do, I study military operators, I study frontline health care, physicians, clinicians, providers, um and professional athletes, all who really struggle with this circadian misalignment. Um But like you said, this isn’t just a problem for shift workers and operators and athletes. This is everyone, right? And I think it’s just raising awareness, like letting people know that, hey, these have profound consequences on your ability to, you know, show up and live your values in a way that, you know, feels good to you. And, and I think once people experience alignment circadian alignment, um they, I think they start to, they, they recognize, I think the opportunity, mentally, physically and emotionally and um and I think once you experience that alignment, it is actually hard to go back and it’s not about being necessarily perfect every single day. But I think thinking about your life in terms of, ok, you know, when, when can I actually align myself with the natural cues in the environment and, and what would that actually look like for myself and my family? Um, I think it’s an important exercise. Um, again, you know, if we want to try to reduce our illness and injury burden, um, which we all do. Right. I mean, I, you know, I think we all, yeah, I mean, all none of us want to get sick, you know, we want to be available for life, you know. Um and I think availability, there are some very specific behaviors that we can deploy that help us be more available. And I always think about this from, you know, from an athlete perspective, you know, availability is everything when you’re coaching a team, like, you know, the more athletes you have who are available to train and compete literally more successful you’re gonna be. Um and you know, not that, that completely trumps talent but availability is everything, right? Um So, but, and I think about that in the context of just, you know, normal people walking around like we want to be able, I mean, you know what it’s like when you’re sick, like the world just, you know, falls apart kind of, you know. Um so, you know, how do we pay that down? Well, you know, we adopt behaviors that promote this alignment.

Dr. Lyon (01:14:43 -> 01:14:45)

and what are those top behaviors?

Kristen Holmes (01:14:45 -> 01:15:33)

Yeah. So definitely, um, viewing light, the moment you wake up is really important, you have to be outside light. Yeah, natural light generally, you know, basically when you kind of step outside, you know, prior to, to 10 AM you, you’re bathing yourself in, you want five minutes, you’ll, you’ll basically expose yourself to about 100 looks of light clothes, no clothes. Um, I mean, the more like the natural lights on your skin, um The better, no question. I mean, vitamin D, um there’s lots of benefits, but this is really about the light entering the retina. So once that light hits the retina, it then um signals to the super cosmetic nucleus and then it, you know, has a downstream signaling to every peripheral clock and, and you know, the central clock, basically, every cell organ and tissue in your body is receiving this information, which is incredible because which is insane. Right?

Dr. Lyon (01:15:33 -> 01:15:34)

Every cell has a clock.

Kristen Holmes (01:15:34 -> 01:16:02)

Exactly. And, and those clocks need to know what to do, right? And they’re anticipating that morning, that moment in the morning where you’re gonna view light. So literally within 20 minutes of waking up, you want to get outside, um you want to view the natural sunlight for 5 to 10 minutes. If it’s super bright out, five minutes is plenty, you’re gonna get that 100 you know, 1000 lutz of light. And this is our hardwired biology. This is hardwired Yeah, there’s, there’s, yeah, there’s kind of no, no getting around this really,

Dr. Lyon (01:16:02 -> 01:16:06)

Most people don’t get up, get outside. No, it’s not adequate to do it through a window.

Kristen Holmes (01:16:06 -> 01:16:11)

It is not. No, it’s just, it’s a lot less efficient. It would take you hours and hours, hours and then the idea

Dr. Lyon (01:16:11 -> 01:16:14)

I’m just sitting there for five hours.

Kristen Holmes (01:16:14 -> 01:17:13)

Yeah. But, um, but yeah, just simply getting outside has lots of benefits, you know. But, but mainly it’s, it is really about getting that, that pulse of light, um which, you know, then you release cortisol, like all of these things, you know, from a neurological standpoint are, are begin firing and it basically tells your, your system that it is time to be alert, right? And, um, and, and that is really, you know, kicks off the ability to, to have, you know, uh high levels of cognitive functioning. Um and, and just energy levels. Um, it also tells your body that it’s probably time to eat. Um So there’s all sorts of things that are, are happening when you view that first pulse of light in the morning. Um And then the kind of behavior that I think goes along with that is that you want to restrict light after the sun goes down. So it’s important that um that because what happens when we view light when after the sun goes down, um your body then thinks it’s time to be awake, right? So it confuses the system.

Dr. Lyon (01:17:13 -> 01:17:15)

And this would be overhead light

Kristen Holmes (01:17:15 -> 01:18:25)

or any kind of any, any kind of, any kind of light really. And you just the, the I think the strategy I suppose is just to dim the lights in your home environment, the best that you can limit the amount of interaction you have with devices, you know, just put the filters on, put the blue light block and glasses try to block, block all that at that light. Um Because what happens is if you have that exposure, your m melatonin production, like the kind of sleepy hormone is um gonna be delayed, it might not be as strong as it typically would be. Um And there’s some interesting mechanism uh mechanisms related to that that I can talk about in terms of um how it impacts our metabolism. But um and me melatonin has neuroprotective effect. I mean, it’s so important. So if we’re not releasing melatonin or it’s, it’s weak. Um that has a lot of lot more consequences apart from just whether or not it makes us sleepy or not. So um yes, that that blue light or that light light after the sun goes down is really gonna inhibit that melatonin production. Um And we might fall asleep just because we’re exhausted, but that is actually going to influence the depth and quality of our, of our sleep over the course of the night.

Dr. Lyon (01:18:25 -> 01:18:29)

Basically, what you’re saying is a good night’s sleep starts actually in the morning

Kristen Holmes (01:18:29 -> 01:19:05)

you can’t, you, you have to fix your keating rhythms in order to fix your sleep. And I think that’s again, I think when we talk about this from an industry perspective that like frustrates me a little bit is because we talk about sleep and we talk about sleep hygiene, which is very important, right? Cold, dark quiet, without a doubt, you know, we need to manage our stress throughout the day. very very important for sleep, but it’s their circadian behaviors that really impact whether or not we’re gonna be able to fall asleep and stay asleep. And I think that’s the second piece to kind of fixing sleep is, is definitely stabilizing or reducing that night to night sleep wake variability.

Dr. Lyon (01:19:05 -> 01:19:10)

And that would mean going to sleep at the same time and limiting light. Anything else

Kristen Holmes (01:19:10 -> 01:19:40)

going to bed at the same time, waking up at the same time is probably the best thing that you can do for mental and physical health resilience. And this is bubbled up in all of the research that we have done. Um We are able to objectively measure when you go to bed and when you wake up. So we have a very clean measure of your sleep regularity or your sleep consistency. The more variable that sleep wake time is the more physical and mental issues we see

Dr. Lyon (01:19:40 -> 01:19:41)

like things like anxiety.

Kristen Holmes (01:19:41 -> 01:19:57)

Yeah. So just general psychological functioning. So, yeah, anxiety, how you perceive stress um you know, with the military operators, the more variability, the more home sickness they feel, the less control they feel in their daily lives.

Dr. Lyon (01:19:57 -> 01:20:06)

Do you think it’s a fatigue issue or is there something else with the circadian biology that affects us above and beyond some of those perhaps known factors?

Kristen Holmes (01:20:06 -> 01:21:05)

Yeah, I think, you know, duration kind of matters which impacts, you know, sleep loss will impact obviously fatigue. Um, but we see independent effects. That’s what’s interesting here. That is interesting is that sleep wake time seems to operate kind of independently and has its own. Um you know, when we’re not, when we’re not stabilizing our time, that seems to have its own effects. I mean, when we think about it has a direct effect on our, on our, on our insulin sensitivity. Um so, and it has a direct effect on melatonin production obviously. So and I mentioned melatonin production as being so important. But that is again, I mean, that’s going to influence your metabolism. It’s gonna influence um you know, your cognitive functioning. I mean, melatonin really is a critical hormone. And I think, you know, if I think about the problems that we have as a society from a health perspective, a lot of it probably goes back to this the the weakness of our melatonin production.

Dr. Lyon (01:21:05 -> 01:21:07)

That is, that’s really interesting.

Kristen Holmes (01:21:07 -> 01:21:07)


Dr. Lyon (01:21:08 -> 01:21:27)

Um so someone is gonna wake up at the same time, go to bed at the same time, light viewing in the morning, dimming the lights at night go overhead as much as possible. What kind of um range is there? Is it safe to say you can wake up with a 30 minute range? 15 minute range? What is the-

Kristen Holmes (01:21:27 -> 01:22:19)

that’s a great question. Um And this is an area that we’re um investigating more in our data to really see. You know, can we actually tell you that, hey, an hour left or right, you know, and the, the, the, the sleep and wake will produce X effect. So we don’t have those data yet. Dr Gina Poe who is a sleep scientist out of um I think she’s Cal Berkeley and I apologize if that’s incorrect, but she’s an incredible uh sleep scientist, a leader in her field. Um She says 30 minutes of variability on either end um is suboptimal. So this is, these ranges are small. I know. And I, I think that’s why, you know, we really see these strong effects. Um Once we get outside that 30 minute block again, we these are prelim data. Um but once we get outside that 30 minute block, I mean, that’s, we see that in our data too

Dr. Lyon (01:22:19 -> 01:22:22)

and you see strong effects on mood, uh perceived stress,

Kristen Holmes (01:22:22 -> 01:24:04)

anxiety Um and, and sleep architecture. So, you know, when you look at a rem on set and then um and looking at, you know, how, you know, how much time we’re spending in these deeper stages of sleep. Uh, sleep wake variability is, is massive. I mean, I’d almost go to say that if you have to prioritize, you know, the length of sleep versus this consistent sleep wake time, go for this consistent sleep wake time. I mean, this is a behavior that I’ve been working on. It’s a hard behavior, I’m not gonna like, you know, like it is sugar coated, like it’s hard to stabilize your sleep wake time, given all the distractions and all the things that you could be doing. Um But once I stabilize my sleep, wake time starting in like 2017, I literally haven’t been sick. I haven’t had a cold. I haven’t now, obviously I do a lot of other things, right. Um But that was like the one massive behavior change. So I keep my, I keep my variability, you know, below 30 minutes for the most part, you know, on average what I mean? I, I do my best, you know, I do my best when I look at it over the course of a month, I’m pretty much, you know, at that 30 minute to 45 minute window of variability. Um But I, I think that that has been the single most important change that I’ve made and has I think, you know, my markers, my blood biomarkers, my, um, you know, my, you know, my inner age, you know, things like that um that I can objectively measure my heart rate variability and heart rate, my fasting glucose. I mean, all of those things have improved significantly. I mean, clinically significantly.

Dr. Lyon (01:24:05 -> 01:24:20)

What about the things during the day? For example, I’m sure that there’s an ebb and flow that’s supposed to happen with light. If we were to imagine that we were outside, there’s sometimes that light is higher and sometimes that it’s different. Are there things within the day that we should be doing?

Kristen Holmes (01:24:20 -> 01:24:50)

Yeah. I mean, getting as much light, natural light as possible, I would say is, is kind of the, um, would be the prescription, you know, if you really want to try to set your circadian rhythm and, um, and, and get quality sleep at night, expose yourself to as much natural light as you can during the day. It’s hard. You know, we work in offices where, you know, we’re just, it’s, it’s really hard, you know, but just whenever you get the chance to get outside, get the light on your natural light and, you know, on the retina, on the face, on the skin, you want to try to do that.

Dr. Lyon (01:24:50 -> 01:25:02)

What about the large sun lamps? If someone is like, I cannot get outside or maybe they can go for a 10 minute walk or maybe they have an hour lunch break. Probably not. Would a, a light box suffice.

Kristen Holmes (01:25:02 -> 01:25:19)

Yeah. I mean, it is, there’s no question. It’s better than nothing. And and that is definitely what we recommend for our shift workers. Um Yeah, to try to, you know, kind of make up for that lost uh natural light, nothing can replace, of course, the natural sunlight. Um But the, the red light boxes are awesome. Yeah.

Dr. Lyon (01:25:19 -> 01:25:42)

What about food? You mentioned food? There’s this huge push. And actually I usually before I met you, I would fast till noon. And when you and I were sitting down and talking about this circadian biology of what the body clocks are meant to do because I think food actually trumps light when it comes to its impact on changing. Uh

Kristen Holmes (01:25:43 -> 01:27:16)

or I mean, light is definitely the strongest mediator for sure. So yeah, so light lightness during the active phase, darkness during the active phase is, is kind of if we’re to put a taxonomy, that’s number one, I would say, you know, your eating window is probably two. Um So there and there’s lots of really good research. I mean, I see this in, in my own data as well. And in the op data, um you know, folks who eat a meal within two hours of bedtime have um you know, it definitely have a negative impact on all the markers of recovery as well as sleep. So in, in what’s happening mechanistically, there is um we digestion is a para synthetic activity, right? So we think of rest and digest. Um sleep is also a para synthetic activity. So when you’re trying to do these both, at the same time, they compete for, for resources and digestion is always going to win out. So we’re always going to bias toward our, our, our system will buy us toward digestion. It’s gonna to take care of that first and then it can recovery do, you know, do all the things that we wanted to do from a recovery and regeneration standpoint. Um So you want to, once you go to bed, like, you know, if you intend to sleep at, you know, 10 PM, you want to basically probably stop eating at like seven, give yourself a three, you know, at least a three hour or 2 to 3 hour buffer between when you um um your last meal or your last calorie and when you intend to sleep and that um will put you in a position to, to really um maximize um all the things that need to happen during sleep that enable you to kind of wake up as rejuvenated and refreshed as possible.

Dr. Lyon (01:27:16 -> 01:27:24)

That’s great advice. I failed to ask this question. Does it matter when someone wakes up and when someone goes to sleep, is there a natural biology for all humans or is everybody different?

Kristen Holmes (01:27:24 -> 01:27:31)

Yeah, everyone’s a little bit different. But you know, to be clear, midnight is the middle of the night, right? So I think the night owls,

Dr. Lyon (01:27:31 -> 01:27:39)

us moms midnight is like three AM I mean, I know I see you. Good night. I know. I know exactly. Is my midnight.

Kristen Holmes (01:27:39 -> 01:28:25)

I know having kids is like the best because their circadian clocks are so darn strong that you cannot go to sleep. But um but, but yes, um no question. Um There, there are certain things that need to happen that if we are awake, they simply cannot happen. So, um what the science says around that is, is basically if we are, if we are viewing light between 11 pm and four AM, are the dopamine system next day doesn’t work as effectively. So the reward system, right? So those nerve transmits are basically dampened when we’re viewing light between 11 pm and four AM.

Dr. Lyon (01:28:26 -> 01:28:38)

Would that lead someone? So if the dopamine system, which is that drive motivation, would that a make someone be less driven or be more likely and more vulnerable to, I don’t know, risk taking behaviors?

Kristen Holmes (01:28:38 -> 01:28:39)

all of the above

Dr. Lyon (01:28:39 -> 01:28:39)


Kristen Holmes (01:28:40 -> 01:29:57)

Yeah, we just, when, when those systems aren’t working properly, it’s hard to make clear decisions about our life. And I, and I think, and, and so just kind of go back to your original question about, you know, when should we be falling asleep? Well, if we know that there’s these deleterious repercussions happening when we’re viewing light between 11 pm and four AM, then we know that. Ok, well, 11 pm is too late to go to bed. So, and if 12 is considered kind of the middle of the night. Then if I’m a night owl, my biological preference for sleep is probably around 10 30 I 11, I would say the latest. Right. I mean, at minimum, if you’re going to sleep at 11 30 you absolutely do not want to be viewing light from 11 to 11 30. Or if you’re falling asleep at 12 AM, you don’t want to view light between 11 pm and 12 AM. So, we, we just, we know that there are serious next day ramifications and obviously if you do it once or twice a month, no big deal, right? Of course, but this will add up and we wonder where all these mental health issues coming from. It’s it’s viewing light at a phase of the natural light dark cycle like that is that is what’s happening here. I think uh when we’re looking at the mental health issues at scale, um I think it comes back probably to um to viewing light in these inappropriate times

Dr. Lyon (01:29:57 -> 01:30:02)

that’s really critical and important to understand. Yeah. Do you wear sunglasses?

Kristen Holmes (01:30:02 -> 01:30:34)

I don’t. No. So I definitely try to um uh take on as much as much light as possible. Um I need glasses to see unfortunately, but um yeah, so yeah, I try to expose myself to as many of the, you know, natural kind of um wavelengths as possible during the day and even at night. So the moon and you know, that also is a cue for your system. So watching the sunset is also really powerful and, and can kind of like, again strengthen that um that circadian system.

Dr. Lyon (01:30:34 -> 01:30:38)

This is an off the wall. Question, the full moon, would that keep you awake or help put you to sleep?

Kristen Holmes (01:30:38 -> 01:30:47)

No, the same kind of same thing with natural, with fire too, doesn’t affect um your, the Melatonin.

Dr. Lyon (01:30:49 -> 01:31:56)

Wow, that’s fascinating. And this brings us back to, you know, we live in this environment where we’re driving cars, eating fast foods, viewing light, just a whole toxic environment, which I I can appreciate because we are a westernized society. This is just what happens with the evolution of humans, but the health is, is worse than ever before. But the opportunity to have good health is better than ever before. That’s so well said. And I, I think that if we can be really disciplined to put some of these practices in place, we have more resources and more wisdom because stand on the shoulders of these giants of individuals who’ve been doing research for decades to now begin to collect the data much like you’re doing and then implement and deploy as you said, and execute. Um So in terms of food, is there a time that again before I met you? I was always telling people to fast until middle of the day, which I don’t actually tell them anymore. Thank you and the my patients. Thank you and the listeners. Thank you from waking up. Is there a time that one should eat.

Kristen Holmes (01:31:57 -> 01:33:16)

Yeah. So I mean, there’s definitely sex differences here too that I think are important to acknowledge. So men seem to do very well with, you know, prolonged fasting. I think women in certain phases of their menstrual cycle will do fine with some longer fasting. So for example, for women who are naturally cycling, I would say during mensies and uh you know, in your, in, in during ovulation, uh you know, those are the times where if I am going to try to extend my um my window uh and my fasting window, I will go to noon. Um just to take advantage of the and all the good things that are kind of happening with fast because I don’t want to say that intermit fasting is bad necessarily. But I think there are times where women are gonna be able to do that, right? Because the phase, so once you get out of um the phase, you know, Menzies in ovulation, you’re in the phase, you’re preparing for Menzies or you’re, you know, or a baby, you know, depending on what what happened. Um And as a surprise um and, and there’s a lot of effort going on in the body. So fasting puts an extra stress on the body that is just um that can have negative consequences and it’s, it’s not that all the protective and, and good things that could, could come from a, a fast um you’re, you’re not able to realize during that phase of your cycle.

Dr. Lyon (01:33:16 -> 01:33:19)

So women should fast during which phase?

Kristen Holmes (01:33:19 -> 01:33:36)

if you’re going to fast faster in the phase. OK. So um after, after Menzies and ovulation in the, yeah, do not faster in the Luga phase. I’m sorry, you want to fast during um either Menzies or um or the, or the ovulation. OK.

Dr. Lyon (01:33:37 -> 01:33:40)

That makes sense. Yeah. And, and then the body kind of primed to do it anyway.

Kristen Holmes (01:33:40 -> 01:35:04)

Um So I wouldn’t, so, you know, there’s not a lot of research on females with regard to fasting. So I just want to caveat that. Um, but what I’ve seen in my own data is that definitely, you know, during that flick throw phase, that’s when I seem to be able to fast and um it doesn’t, you know, disrupt um my sleep or, you know, my, my markers look good. Like I, I think that it would be, that would be the time if you’re going to do it. Yeah. And then during the luga phase, you just want to ensure that, um, yeah, you probably want to eat within, you know, an hour or so of waking up and, and I think back to the keating component though, um, for both men and women, if we wait to eat all of our calories toward the back end of the day, we are definitely metabolically not as primed to use those nutrients and, and digest those nutrients. So we want to try to get a bulk of our protein, you know, kind of earlier in the day. So. Ok. Good. Yeah. Um, yeah, it’s good to hear you say that. So, you know, between seven AM and four PM we want to try to get as much protein as possible and that’s when we want to get the bulk of our calories. And we’ve seen in studies when people, um, miss breakfast, they tend to actually eat more calories. So, um, so I think there is something to be said about, you know, eating three squares a day, um, or if you’re going to have two meals, um, you know, biasing toward, uh, breakfast and lunch,

Dr. Lyon (01:35:05 -> 01:36:12)

what is, what’s, um, I think fascinating is when you look at some of the nutritional research and Heather did breakfast, skipping, um, meals. So she looked at a group of, uh, female adolescents and they skipped breakfast. Those that skipped breakfast. Exactly what you said would be, uh, at a metabolic disadvantage. They also craved higher calorie foods later on. Um, but what’s interesting is, is thinking about all the nutritional research, the majority of them don’t take into consideration sleep wake cycles. I know and potentially that could be the next layer of what is the impact, right? We, we typically look at, you know, we always, you know, I would, I say always, but typically the first meal of the day when you’re coming out of an overnight fast is what we test, it’s certainly what’s tested in muscle protein synthesis, you know, and, and a multitude of other metabolic nutritional interventions. But very rarely, I, I don’t even think, I think maybe I’ve seen one study that takes into account that circadian biology.

Kristen Holmes (01:36:12 -> 01:36:29)

Yeah. I mean, that the deregulated sleep wake time has huge implications on next day, relin and leptin levels. So, I mean, there is a very, very strong link link between night, night to night sleep wake variability and, and, and uh glucose metabolism.

Dr. Lyon (01:36:30 -> 01:36:45)

Hm. So the first meal of the day doesn’t matter, the composition from a circadian standpoint. I know that it is, the, the composition certainly matters from a metabolism standpoint. Do you think that it matters from a circadian standpoint or do we not have that data?

Kristen Holmes (01:36:45 -> 01:37:49)

And that’s really interesting that those data might exist? Um But um yeah, I’m not quite sure what, what, what I would say. I’m just trying to think like, logically, um you know, I, I still think that, you know, fueling for, you know, whatever your activity you’re engaging in is, is kind of the right way to think about your fueling during the day. I don’t know if you agree with that, but, you know, if I’m going to work out, like I’m going to take on some more carbohydrates, you know, to, to kind of prepped for that, um for that, for that effort. Um If I’m trying to think I’m gonna have more fat, more protein. Um, yeah, I, I, I mean, I have protein every meal, of course dr Lyons. I know. Don’t worry about that. Um, but I’ll have, you know, I have protein and fat if I’m really trying to, to kind of think and then if I’m working out it’ll be protein and, um, and carbohydrate. So, I don’t know, I mean, I think from a, you know, we want to just try to get that those array of nutrients as early in the day as possible, I guess is the, would be the thinking

Dr. Lyon (01:37:49 -> 01:37:55)

that, I mean, that, that makes sense in terms of meal timing. Do you have thoughts on consistency of meal timing?

Kristen Holmes (01:37:56 -> 01:38:28)

Yeah, I mean, again, our body just loves regularity. You know, from a circadian standpoint, we’re anticipating um, cues in the environment, right? Our, our body is anticipating light, they’re anticipating darkness, we’re anticipating exercise and activity, we’re anticipating food. So, yeah, we absolutely, um, want to try to, again line up those endo endogenous pro preferences with our actual behavior. So that means that, you know, our body is going to expect, you know, food around seven and around noon and around four or five and you can train it for sure.

Dr. Lyon (01:38:28 -> 01:38:37)

Yeah. And you recommend stopping eating two hours before going to bed or do you actually recommend stopping it even earlier? For example, when the sun goes down

Kristen Holmes (01:38:37 -> 01:38:54)

as early as you can get away with, honestly. Yeah, I mean, once, once the sun goes down, if you can, you know, you don’t want to wake up hungry, you know, you don’t want to wake up the night because you’re starving. And I know a lot of the guys that we work with professional athletes and, and operators and, um, you know, they’re just, their metabolism is going so fast. So, those guys are

Dr. Lyon (01:38:54 -> 01:38:57)

eating hormeal chili under the table guys.

Kristen Holmes (01:38:57 -> 01:39:05)

Oh, my goodness gracious. Yeah, I know what you’re eating. Yeah, I have some really funny stories about, yeah. Um but

Dr. Lyon (01:39:05 -> 01:39:12)

by the way, when we were at triple seven, the food choices were really suboptimal. They just want to throw that out there. Mike Sirelli

Kristen Holmes (01:39:13 -> 01:40:47)

that’s right, Gabriel and I were like, I don’t know, splitting a kind bar so bad. Um But anyway, we digress. Um Yeah, so um yeah, so I, I think ideally we stop eating. I, I would say three hours. Um You know, I can for me just once the sun goes down I stop eating obviously in the winter, the sun, you know, it’s like 4 30 that’s not as practical. Um But I give myself, you know, an hour buffer of when the sun goes down and, and when I finish kind of my last calorie. Um but I would say, you know, if you do have to eat. Um you know, and we actually were looking at this research together. I feel like a few weeks ago. Um You know, case and protein, you know, you just stuff that’s easily digestible, um seems to not, you know, impact um sleep architecture and, and sleep onset. And so I, I think, you know, and I think there’s more research that needs to be done in that area. These sample sizes are quite small, but it seems like caine is, um you know, is, is, is, is ok to eat before for sleep. And, you know, it’s say if you have some walnuts, you know, again, that will help with the, um you know, feeling satiated. Um and walnuts is, is actually uh a precursor to Melatonin. So as is raspberries. Yeah. So they’re both precursor to Melatonin. So, um so those, those could actually, you know, benefit you Kiwis. We see too also. Um Serotonin. Yeah. You know, those are all precursors to Melatonin. So anything higher in Serotonin, I, I would say is OK to eat. Um But other than that, you know, I think we, we probably want to try to

Dr. Lyon (01:40:47 -> 01:40:50)

Do fluids impact the circadian biology?

Kristen Holmes (01:40:50 -> 01:40:53)

if they have calories, but if it’s just water, no, it’s totally fine. Yeah.

Dr. Lyon (01:40:53 -> 01:41:00)

  1. So then there’s no cue that uh would impact. So, OK, that’s good to know exercise.

Kristen Holmes (01:41:00 -> 01:41:47)

Yeah. So the research is really mixed. Um There’s actually this pretty large study but I, I think when I really looked at the study, I, I wouldn’t say that it um accounted for a lot of the confounder that I think, tell you whether or not it’s a good or bad study. So, uh I’m gonna dismiss that study. But, um, but I would say just in principle, the more active we are in the lead up to bed. Um, generally that’s gonna make my ability to kind of wind down and prepare for sleep. It’s gonna extend that time. So I just think in principle and I think it’s, it’s highly variable, you know, um I, you know, I think if we’re going to the gym at nine PM and we’re working out and we’re exposing ourselves to a bunch of overhead light, it’s just going to make it really hard to fall asleep.

Dr. Lyon (01:41:47 -> 01:41:54)

You probably go back and forth, which is more important. Sleep or exercise, getting the training in, but probably sleep because the next day.

Kristen Holmes (01:41:54 -> 01:42:36)

Yeah, I mean, exercise, I, you know, I definitely go back and forth because exercise is just so, so, so important. Um, but, you know, you want your hormones and you want, you want everything in your body like working as it should, you know, so you gotta, you have to weigh the cost benefit. Um There’s no question and um, yeah, I mean, I, I think I’m kind of biased toward believing that we need to get the sleep. We, we, we need to be sleeping, right. So, um, yeah, so I think, I think that, um, you know, maybe some days you’re gonna prioritize exercise oversleep potentially. Um But Yeah, I mean, do whatever you can to kind of do it during the act of phase of restricting rhythm.

Dr. Lyon (01:42:36 -> 01:42:59)

And that, that would also probably, um, be the same for medications you probably want to dose medications similar to a body rhythm, whether it’s testosterone or estrogen progesterone. Um, I’m assuming that, that, I don’t know how impactful that is, but I, I would guess that there’s probably a role for circadian medicine in administration.

Kristen Holmes (01:42:59 -> 01:43:35)

It’s called chrono medicine and it’s, it’s an emerging field. Yeah, it’s really exciting. And I, you know, this is not my area of expertise necessarily in the sunset. Um, you know, I think every medication is going to be slightly different but there’s no question, you know, even if you’re taking an NSA, you want to take that earlier in the day. Um I mean, we see, I, I’ve seen in, in our data um with athletes that an NSA can impact sleep, um uh it can impact sleep uh negatively by up to 15%. Yeah. So, which is interesting. So when it’s taken, um in, you know, within a couple of hours of, of bed.

Dr. Lyon (01:43:35 -> 01:43:37)

So, have you guys seen anything about P P I S?

Kristen Holmes (01:43:38 -> 01:43:42)

Uh No, but that would be very interesting to look. It would be too. Yeah.

Dr. Lyon (01:43:43 -> 01:43:53)

Now you talk about other things, you talk about hormetic stress and heat and cold, tell us some of the other things that really make people more adaptable

Kristen Holmes (01:43:54 -> 01:46:40)

Yeah. So, Um So there’s things, you know, I kind of, I kind of put this in the recovery um bucket. So, you know, certainly what we put into our body, air fueling is really critical. Um And, and this is an area that you, you talk about a ton, but I think there’s some really, you know, nutrient dense food, prioritizing protein, you know, all these things are really important that’s gonna impact our ability, obviously to adapt functionally to external stress. Um Hydration, very important. Um And I would say kind of in, you know, the hydration bucket or, you know, um or just putting liquids in our body, we want to avoid alcohol at all costs. That is going to disrupt sleep, that is going to impair next day recovery. Executive function, I mean, it’s gonna impair every part of your body. So from a recovery standpoint, if you’re looking to optimize recovery, don’t drink, don’t drink. Yeah, I mean, it’s just, it’s a toxin that you’re putting in your body and it just, …yeah, and you divert all of your resources get diverted away from recovery when your body is having to metabolize a poison. So I would think really carefully again if you’re interested in optimized recovery, that would be something I would avoid. Um I think too like, I mean, we see this very clearly in our data. I mean, that is the one behavior that is most predictive of um if people consume alcohol within a couple of hours of bed time, um it crushes your sleep. So, you know, your ability to get in deeper stages of sleep is totally compromised. And then you wake up with a substantially hr V which we talked about in the beginning of the podcast. Um is a marker to help you understand how effectively you are adapting. Is there a number that people should shoot for? So it’s totally um variable. Yeah. So, you know, your HR V is going to be different than mine. Um It’s based on genetics, heart size, you know, a whole bunch of factors influence your HR V. Um that said, um I think people who have lived a relatively clean lifestyle seem to have a higher, you know, baseline hr V which makes sense, but it’s all relative to yourself. So, you know, you kind of look at, OK, where am I today? And then you want your HR V to kind of increase over time, you know, and, and that’s one of the markers when I made that big kind of lifestyle change and started. I’m like, all right, I’m going to stabilize my soup break time. That’s one thing that I’ve seen. I mean, HR V has increased um 40 milliseconds, which is just, you know, insane. I was in the sixties and I’m in the hundreds now. So it’s just crazy. Um But uh but Yeah, I mean, I, I think we need to think very intentionally about the liquids that we’re putting in our body. Um and prioritize water, we uh the other thing that we see in our, in our data relative to recovery is, is dehydration obvious also has a huge impact on markers of recovery as well as uh sleep.

Dr. Lyon (01:46:40 -> 01:46:42)

What about caffeine and nicotine?

Kristen Holmes (01:46:42 -> 01:46:55)

Yeah. So um nicotine, I’m not sure. Actually, I don’t, I don’t, I haven’t seen any data around nicotine. Um I think that’s probably because the folks on our platform, very few people probably smoke or report smoking. So um

Dr. Lyon (01:46:55 -> 01:47:01)

what about dip and true nicotene gum Exactly. I’m just curious. I mean, yeah, we

Kristen Holmes (01:47:01 -> 01:47:05)

we need to do a study on dip actually Actually, I’m so curious about that. I, I

Dr. Lyon (01:47:05 -> 01:47:07)

think it’s full of participants. I

Kristen Holmes (01:47:07 -> 01:47:13)

know, I know, I know dipping is bad. Yeah. Yeah. And the

Dr. Lyon (01:47:13 -> 01:47:14)

nicotine, we don’t know. What about

Kristen Holmes (01:47:14 -> 01:47:48)

caffeine? Yeah. So caffeine within, you know, basically after 12, nothing surprising with caffeine. It’s definitely going to impact sleep onset, definitely fragments, sleep um when you’re taking it within a couple hours of, of bed. Um So yeah, I mean, being really smart about the timing of, of, of your caffeine is, is critical and obviously there’s a key component to that. If I were to say, you know, of the poor circuiting behaviors that we kind of outlined, I would kind of put caffeine in that as Well, just because that can impact our, um when we release Melatonin, you know, via identity.

Dr. Lyon (01:47:48 -> 01:47:53)

That makes sense. Yeah. So we talked about exercise. Now the question that everyone else wants to know is sex.

Kristen Holmes (01:47:53 -> 01:47:54)


Dr. Lyon (01:47:54 -> 01:47:55)

Asking for a friend.

Kristen Holmes (01:47:55 -> 01:48:13)

Yeah, I mean sex. So, um generally speaking sex with a partner, um uh close to bed, um seems to have a positive effect on sleep and a positive effect on mental health, which is not surprising. Yeah. So we see this, we’ve seen this in the data which has been really fun to exam

Dr. Lyon (01:48:13 -> 01:48:16)

So sex closer to bed time, not in the day. Got it.

Kristen Holmes (01:48:17 -> 01:48:23)

Um Oh, you can have it during the day too. I mean, I think, I think sex at any time is probably a good

Dr. Lyon (01:48:23 -> 01:48:32)

thing but it doesn’t affect sex before bed does not affect someone’s circadian. In fact, maybe it has a positive impact. Let’s talk about.

Kristen Holmes (01:48:32 -> 01:49:08)

Do you have, well, I would just say that for men, it probably will help them fall asleep faster for women. Um Not as much like we want to cuddle after sex, we want to kind of talk and stay awake a little bit, which is so interesting. Why, why were we made like that? I’m like, I’m just kidding saying this is what the science says about Oxytocin, like what we release um versus what men release after sex is a little bit different. So our needs after sex are a little bit different generally. Um So not that sleep onset for women would be, you know, egregiously impacted, but um maybe delayed, slightly relative to a guy.

Dr. Lyon (01:49:08 -> 01:49:19)

Now, uh That’s a good question. And what, what is the next question I was? Oh yeah, heat, cold, other activities. So you jump in this freezing cold right

Kristen Holmes (01:49:19 -> 01:51:53)

now. I’m very, very passionate about colds. Um Yeah, I love talking about it. Um And, and, and practice this myself. So there’s actually some really good, some new research that came out that from a protocol standpoint. So what doesn’t kill you makes you stronger? So this is kind of this concept of hormesis and exposing yourself to extreme temperatures. Both heat and cold can have a massively bene beneficial um impact on recovery, right? So um we see, we see this certainly see this in the data, but as it relates to cold specifically, um from a protocol standpoint, we you want to try to once per week submerge yourself neck down in uh like 37 degree temperatures which is very cold. Um And for like two minutes and then four other days of the week, do a 32nd cold shower, how cold? Um So just, you know, I know some pipes in Boston are very different to the pipes in Texas even a little bit different than the pipes in New York which um my um shower today was disappointingly a little warm. Yeah, people are so soft. Um but you have um So you basically, the brown fat is kind of in your back and kind of your neck and your head. So you basically want to shower where it’s kind of hitting your head, um, into your back. And, um, that’s, and we activate the brown tissue, but it was really cool. The study showed that with that protocol, um, the subjects uh reduce body fat and, you know, improved body composition and, and mentally felt, you know, better, more alert. Um So it was a really nice study and with just 30 seconds, 30 seconds, four times a week and then one time a week emerging for two minutes in this really cold water. Um But that, you know, and it sounds like, you know, I think the effects are pretty significant on just um our mental health resilience and that’s been shown. Um There’s a really good study in Amsterdam that looked at, um the experimental group did cold showers, uh five days a week. Uh The control group did not and they looked at um uh sick days and they looked at, uh and they had a bunch of mental health surveys and, and the group who um who took part in these cold showers had uh many fewer sick days, um and had um much better and showed a lot of increase in mental health resilience.

Dr. Lyon (01:51:53 -> 01:52:02)

Do you think that the cold shower is, or the, the cold plunge and the cold shower is because they’re proving to themselves that they can do something and withstand difficulty.

Kristen Holmes (01:52:02 -> 01:52:38)

I think there’s definitely a mindset component for sure. Um, you know, I’m from New England so I’ve, you know, been swimming in cold oceans for my whole life. So I think it’s like a little bit less of a mindset thing for me. It’s more of just like I wanna have, you know, the benefit from, you know, this brown fat activation and everything that, you know, uh cascades metabolically from that, um, is, is what’s really interesting to me. But, um, but yeah, I think there’s absolutely a mindset component. I mean, it is uncomfortable. I mean, it was adapted as I am like, it still is like, you know, when you’re getting into 37 38 39 degree water, I mean, that is, it feels very, very cold.

Dr. Lyon (01:52:38 -> 01:52:39)

Do you have to build up to that?

Kristen Holmes (01:52:39 -> 01:53:41)

Um I think so. Yeah. Um, you know, some folks maybe not but um, I think you just have to really, you know, go with a buddy and, you know, just, just be like, all right, we are going to do this, you know, and maybe it’s just 15 seconds and then it’s 30 seconds and then, I mean, two minutes can feel like an eternity, you know, when it’s, when it’s, when you’re in 37 degree water. So, um, and, and there is definitely, it doesn’t, you’re not going to, you know, increase your benefits the more time you spend in the cold water. I mean, there is, it’s really important like you don’t and same with sauna, which we can talk about in a second, like, you know, there is a point of diminishing return. Um And not to mention like you could die in seven minutes being in those kind of temperatures of cold water. So that’s not what we’re trying to do here. Um So I definitely advise going with a friend, you know, don’t engage in, you know, Sumo breathing in the water clearly, you know, so I there’s certain behaviors, recovery behaviors that you want to stack, that is not one of them. Um But yeah, I mean, definitely that the that cold shock is um is incredibly powerful for hormesus and um and you know, can really amplify recovery

Dr. Lyon (01:53:41 -> 01:53:46)

does it matter the time of day and when you do it regarding workouts?

Kristen Holmes (01:53:46 -> 01:54:31)

Yes. So I think um yeah, so I, I would say um because, you know, you release dopamine and, you know, it’s like uh you feel really alert after the cold water. Um I would say you probably want to do it in earlier in the day. Um Also, you know, if you’re doing a cold shower, for example, before bed, um that actually is going to um make your body warmer and you know, that we know that in order to kind of fall asleep, your body actually has to your core body temperature needs to drop by two degrees. So um we actually want to take a hot shower before um or to a sauna before bed. So I would say heat in the back half of the day, cold in the front half of the day would be my kind of recommendation because of its influence on sleep.

Dr. Lyon (01:54:31 -> 01:54:31)

That makes sense.

Kristen Holmes (01:54:31 -> 01:55:30)

Yeah. And exercise. Yeah. So this is actually been so fun experimenting. So my son plays ice hockey and well, so I work with, you know, just, or I’m in contact with a lot of ice hockey players in particular and we’ve been, um and I’ve been experimenting with this personally where I do just like a 30 second, like quick dip and then I get dressed and then I do a workout and I just feel so good and it, it sounds so counter intuitive in that, you know, you’re cold, you’re getting your body cold before a workout. Like, don’t you warm up? And it doesn’t mean you don’t do your warm up necessarily. But I think it’s just the um all these, you know, adrenaline epinephrine and, and dopamine like all these things that are released from the cold just gets you primed to work out. So, um all the ice hockey guys have been doing like 30 second showers um before the game and, you know, again, it might just be a mental thing. It’s like a bonding thing, but I think they get the surge and um yeah, and my son’s ice hockey team has now been doing it, which is so cool.

Dr. Lyon (01:55:30 -> 01:55:34)

Yeah, they have a lot of, uh, assets. Right. So, they know exactly what they need. Yeah.

Kristen Holmes (01:55:34 -> 01:55:39)

Yeah, I’m not shy about kind of helping with the load management with, with those guys. Yeah.

Dr. Lyon (01:55:39 -> 01:55:41)

And then what about Sauna? Yeah.

Kristen Holmes (01:55:41 -> 01:56:37)

So, um, in this area I suppose I know maybe a little less about but, um, I’ll say just from the folks who know a lot about it, I will just regurgitate what they’ve said. And um basically, I, I think it’s 1 74 is the kind of the temperature. Um, and you can certainly go more than that. And again, the more adapted you are to the heat, um kind of, I think the higher temperature you can go, there might be a temperature where it becomes unsafe. Not exactly sure what that would be. Maybe around kind of two 20 minutes or something. It’s gonna be different for everyone. So you have to experiment and I know red light versus um kind of dry heat different. Um, but both seem to have positive effects. Um And it sounds like from the research that, um you know, you want to spend about an hour over the course of a week, um exposing yourself to heat 20 minute sessions is ideal. So three or 4, 20 minute sessions per week seems to be ideal.

Dr. Lyon (01:56:37 -> 01:56:43)

And does it matter? So you said that probably closer to bed or later on in the day.

Kristen Holmes (01:56:43 -> 01:56:59)

I think so because it’s gonna, it just makes you feel, yeah, it makes you feel relaxed. And, um, I mean, I think you, you know, you’ve probably done a song, of course, you know, and you probably have them. Yeah. So, yeah, I mean, I think for me it always just makes me feel relaxed. I just want to stretch and, you know, just like, kind of hang out.

Dr. Lyon (01:56:59 -> 01:57:22)

I just want to hide in there. No, not home, not available, not available. Is there anything else that you see that really sets people apart in terms of either good or bad? I mean, we really highlighted the uh sleep wake time is critical. Food timing is critical. Don’t use alcohol uh train if you can earlier on in the day, prioritize

Kristen Holmes (01:57:22 -> 01:57:24)

sleep stop, caffeine 5 12 1 PM.

Dr. Lyon (01:57:25 -> 01:57:33)

No, these are all really great takeaway tips. Is there anything else that you see consistently either good or bad that maybe we haven’t touched on?

Kristen Holmes (01:57:35 -> 01:57:45)

Yeah, I mean, training is really important, you know, I I would say that people probably don’t do enough sprinting.

Dr. Lyon (01:57:46 -> 01:57:56)

I was gonna ask you about that. I actually was going to ask you about that. Yeah, I was curious as to how that really impacts in terms of being able to relax and recover because when you’re done sprinting, you’re exhausted. Yeah,

Kristen Holmes (01:57:56 -> 01:59:12)

I, I think there is something different about sprinting and I think there’s a mindset component to that too. But I think when you consider just markers for age, like for aging, like, I feel like if you can stay fast, like you’re, you know, you’re on a good path in terms of like longevity. And um so I, I guess I see it and there’s actually a really interesting study with master sprinters looking at telomere length and master sprinters had more telomere length than um individuals who don’t sprint. Um So I, I do think there’s this kind of aging component with sprinting that is, is um is really compelling. Um But yeah, I mean, I would say that people don’t probably do enough in zone five, you know, and that I think people spend a lot of time in these submaximal efforts and I think particularly for women. Um you know, we know Doctor Stacy Sims and she was just, um I just spoke to her the other day on, on this topic specifically and um you know, I think for women who are in menopause, uh you know, resistance training and, you know, these sub these maximal efforts are actually really, really important. Um So I, I think that I, I would say that probably spending time in those, those maximal efforts is needs to happen more. Um

Dr. Lyon (01:59:13 -> 01:59:15)

Yeah, and that could start one day a week.

Kristen Holmes (01:59:15 -> 01:59:38)

Yeah, I mean, really, I think the kind of prescription is, you know, get out of breath twice a week for a couple of minutes like that’s it, you know, and if you do that then you’re, you’re on your way, you know, and it’s, it’s just, you know, go in your driveway and sprint, you know, find a, you know, just find 100 m somewhere and, you know, a field and, and just go, go, you know, they could do

Dr. Lyon (01:59:38 -> 01:59:39)

Airdyne rowers.

Kristen Holmes (01:59:39 -> 01:59:54)

Yeah. Yeah, I think, yeah, if, if people aren’t into running, you know, there’s other ways to kind of definitely to reach those maximum efforts. But I do think if you’re capable and, and able, I do think there’s something about having your feet on the ground and kind of moving fast.

Dr. Lyon (01:59:54 -> 02:00:26)

I love that. The, you know, you do talk a lot about data. I also know that you have another side to you, which is really that psychological side. And again, you’ve worked with athletes, you’ve been an athlete, do you see one thing or perhaps one character trait? And maybe there isn’t one that really allows people to be resilient and adaptable that you’ve seen over, not just, you know, working with the athletes that are utilizing, but just over your career because you’ve had quite a long career and you didn’t mention how well Princeton did.

Kristen Holmes (02:00:27 -> 02:00:29)

Yeah, we had a lot of success.

Dr. Lyon (02:00:29 -> 02:00:33)

Yeah, pretty, I mean, I think that they, what was the, the record,

Kristen Holmes (02:00:33 -> 02:00:39)

I think. Yeah, I mean, we won 12 Ivy League championships, so 12 conference championships in 13 years in a national

Dr. Lyon (02:00:39 -> 02:00:44)

championship and when you left there were tears of sadness. No, I mean, pretty incredible.

Kristen Holmes (02:00:44 -> 02:04:37)

They have. The current coach is just, is really phenomenal. She’s a dear, dear friend of mine. And it was kind of funny because when I knew I was leaving, I was like, Carla, you need to, you need to come take over here and, and she has, and she, she’s, she’s done phenomenally. So, um, yeah, so they’re in good hands. But, um, but yeah, it, it was a, it was, it was an awesome time and, you know, I would say, yeah, I mean, I’ve worked with Olympians and I’ve worked with professional athletes and, you know, I would say there’s a couple of things that I think separate them and this is gonna sound so counterintuitive but they don’t compete, they, in the sense that they’re not competing with the people around them, they’re competing with themselves 100% of the time. Like, and, and they just, they don’t have this like self consciousness that I think is what holds a lot of us back. It’s just, they’re so focused on the work and, and the quality of their work and they just are absorbing that and everything else just falls away, you know, and I think that’s what I’ve always admired in, in the athletes. And I, and I think, you know, one of the, the principles that I live my life by is that, you know, I’m I’m not gonna, I’m not gonna compete, you know, I, I, I, no one is gonna be better be me than me. So I’m just gonna be me and, and I’m gonna, you know, I’m just, I’m going to absorb myself in, in the things that I really care about and I’m gonna live my values and, and that’s all I’m going to focus on and, and I think if, I think if we can do that, um the outcomes kind of take care of themselves, you know, and, and we get pushed toward, we almost don’t even need goals at that point because we get pushed toward the, the things that we’re really excited about and that, um and, and then, and we’re willing to kind of grind through the less glamorous points to kind of just pursue that work. Um So definitely, I think, you know, not competing is, is definitely an attribute that I see um in a, in a lot of the really successful athletes that I’ve worked with and I think number two is self awareness. So, um and I would say, you know, I’ve had just some exceptional leaders that I have come across and they always carve out time to think like they spend time alone, they don’t seem distracted by things. Um They’re just really clear about their life, but they’re all those things because they, they create space for themselves daily to, to really think and, and I would say that that is the superpower of the 21st century is being control of your attention and control of your thoughts. And, but if you don’t make space to actually understand the contents of your mind, you’re fucked and sorry, you’re screwed, you can edit that out whatever. But I, you know, but, but I, but I think that, that, um, you know, to me, like when I think about, you know, all the, the academic work I’ve done in the, in the field of psychology. And, you know, for me, you know, you start with self awareness and, and you start to build a framework for yourself that helps you understand that internal dialogue. Like if you, if you are not able to understand the conversation that’s happening internally, it’s very, very hard to make clear decisions about your life because a lot of what goes on in our mind, that wheel that turns is generally nonsense. So we need to be able to discern, ok, what is nonsense and what is worth keeping, the stuff that’s worth keeping is who you want to be. The nonsense is who you don’t want to be. But if you allow that to dominate or got at worst, you’re not aware of it, you end up flinging yourself in all sorts of directions.

Dr. Lyon (02:04:38 -> 02:05:08)

I think that that is some of the most valuable information that any of the listeners have heard in all the podcasts. Well, and here’s why, what you just shared is taken from personal experience and also taken from some of the best in the world. And you’re showing us one of the defining attributes of these individuals that you’re right, completely counterintuitive and they’re undistracted.

Kristen Holmes (02:05:08 -> 02:05:09)


Dr. Lyon (02:05:09 -> 02:05:18)

And they’re not competing and they are fully invested in being the best version of themselves. And that’s powerful.

Kristen Holmes (02:05:18 -> 02:05:21)

Yeah. And defining that for themselves. You know,

Dr. Lyon (02:05:21 -> 02:05:42)

Kristen Holmes, you are you a I love you too. You are an amazing, amazing human. Everyone should know who you are and in due time they will. And we’re gonna include all your links and your link, it, your Instagram and your whoop and all your uh amazing things that you’re doing. Thank you so much for spending time with me.

Kristen Holmes (02:05:42 -> 02:05:44)

Thanks for having me. It was a pleasure.