The Food Medic - S6 E2: How wearables can optimize health and performance with Kristen Holmes

Episode Date: July 13, 2021

Kristen Holmes is the Vice President of Performance Science at WHOOP. She works with top researchers and hundreds of the best tactical, pro and collegiate athletes and teams in the world to optimize training, recovery and sleep. In addition to her extensive professional and academic background, Kristen was a 3x All American and 2x Big 10 Athlete of the year at the University of Iowa competing in both Field Hockey and Basketball. She was a 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.This episode covers:- Kristen's extensive academic and sporting background- How she became interested in wearable technology - What makes WHOOP different to a fitness tracker or smart watch- New and exciting research that WHOOP is currently doing- Heart Rate Variability (HRV) and strategies to improve recovery- Nutrition, meal timing, and wearables - Insights into sex and gender differences when it comes to performance and recovery - Scientifically proven tactics to improve sleep- The most impactful changes we can start today to improve performance + everyday health.If you loved this episode make sure to give it a review, rating (hopefully 5 stars) and share it with your friends and family. instagram/twitter/facebook: @thefoodmedicwww.thefoodmedic.co.ukThis podcast episode is sponsored by WHOOP. Right now, you can get your first month free when you checkout through join.whoop.com/thefoodmedic Hosted on Acast. See acast.com/privacy for more information. Learn more about your ad choices. Visit podcastchoices.com/adchoices

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exclusions and terms apply. Instacart, groceries that over-deliver. Hello and welcome back to another episode of the Food Medic Podcast. I'm your host as always, Dr. Hazel. Thank you so much for your feedback on last week's podcast episode with James Clear. It seems that all of you loved it just as much as I did, which wasn't a really big surprise, if I'm honest. But if you missed it, make sure you go back and listen to it after this episode, because there were a lot of great takeaways. But don't go anywhere just yet, because I have an equally great show lined up for you today. Our guest is Kirsten Holmes, who is the Vice President of Performance Science at WHOOP.

Now WHOOP are kindly sponsoring this season of the podcast which I am incredibly grateful for and very excited about. So when we set the partnership up I asked if I could sit down with Kirsten and get really geeky about the science behind WHOOP and how we can enhance our performance and recovery. Kirsten works with top researchers and hundreds of the best tactical pro and college athletes and teams in the world to optimize training, recovery and sleep. In addition to her extensive professional and academic background, Kirsten was a three times All-American and two times Big Ten Athlete of the Year at the University of Iowa, competing in both field hockey and basketball. She was a seven-year member of the US 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. She is an incredible woman and I'm very excited to speak to her today.

Today's podcast is brought to you by our sponsor Whoop. Whoop is one of the most popular fitness wearables right now. It's a 24-7 digital fitness and health coach that provides actionable insights to help you recover faster, train smarter and sleep better. Whoop is unlike most other wearables in the sense that it doesn't just tell you what you've done but it tells you what you really need to know. So I've been using my Whoop for a few months now and I am so impressed with the amount and level of insight it can provide you. So each morning when you wake up you get a recovery score from Whoop based on your sleep and other recovery metrics such as heart rate variability and resting heart rate. That score

helps to guide your day whether you should push yourself and go all out, pull it back a little or actually just take a rest day. The greatest feature for me is the built-in sleep coach which lets you know how much sleep you should be getting based on your expected activity for the following day. It also tracks all four stages of sleep so you can get a breakdown of how much REM and slow wave sleep you got. It's allowed me to figure out ways which work for me to optimize my sleep. Whoop can help anyone perform better whether you're preparing for 5k, training for an event or just looking to build healthier habits Whoop can help you make smarter lifestyle decisions with data that is personalized to you.

Right now you can get your first month free when you check out through join.whoop.com slash thefoodmedic. So thank you so much for joining me today. Thank you for having me. I've been really excited to have this conversation and doing the prep for the podcast, just learning a bit more about you. And you've got such an interesting background. So I think I'd just love to start there and learn more about kind of what you've done in terms of academia and also your sporting background and what you're doing now. Yeah, it's definitely varied. I've spent most of my life in sports and athletics. So, and that's definitely where my kind of academic interests lie. I've always been really fascinated by the interplay between the psychology and the

physiology and unpacking that. So a lot of my academic work has been centered around that. I have a master's in psychology and sports performance and a PhD candidate at the University of Queensland. So my working hard on a dissertation looking at the impact of circadian alignment, autonomic control, and physiological feedback on measures of resilience. And then athletically, yeah, I played a couple of sports in college in the Big Ten at the University of Iowa. I played field hockey and basketball, and then went on to play for the U.S. field hockey team. And one of my most heartbreaking final matches was in this stadium in the United Kingdom at Milton Keynes.

We lost to China in the Olympic qualifier. So, yeah, it was quite sad. Yeah. And so now you are the VP at Whoop. And what does your role entail there within the company? Yeah, so I primarily aim to stand up research where we can look at various behaviors and then, you know, tie them back to the metrics that we track at Whoop. So really trying to understand, you know, what behaviors lead to optimal biometric outcomes, and then trying to take those insights and

productize them. For example, if we learn the ultimate breathing protocol for sleep, we would want to build that into the app. So we've got some research going on that answered that exact question, actually, which is quite exciting. It's in peer review right now, so I can't reveal the actual protocol, but the whole intent of doing this type of research is to better understand how to apply our effort. You know, there's a lot of noise, I think, in this industry, just generally, you know, the health and optimization industry that is. And, you know, it's really kind of my life goal to pull the signal out and make that accessible to folks so they understand, you know, how to apply their effort, you know, if in fact, you know, longevity and optimal health is a goal. Absolutely. And so how did you first get into wearable technology? measure external load and internal load. And obviously, we're taking in tons of subjective markers as well. And what I noticed in the data over the course of the 10 years or so that we

were tracking all of these things is that there was very little relationship to what was happening during training and next day capacity. So what I was doing to them during the training session didn't really have a strong relationship to how they showed up the next day. So what I came to realize pretty quickly is that it's the other 20 hours that they're not with me that has the most impact. And this is where I started to really dig into some of the other factors that influence performance outside of just training load. So looking at factors like sleep and hydration and nutrition and, you know, and psychological influences like purpose, efficacy and control. And in a lot of this, I'd been studying prior to even arriving at Princeton

University where I was coaching. So I was already kind of putting together this performance education over the span of my career and delivering that to my student athletes. But what was tough, I think, is that there was very little quantification of some of those factors. So I started building my own technology at Princeton to really try to quantify some of these other behaviors that were going to influence the capacity of my athletes, you know, to kind of show up for training and be able to do the work. So, yeah, so that's kind of where my interest really was sparked was just this knowledge that training actually had very little to do with next day capacity, which I think is quite an aha moment for most people. And people might come, you know, with pitchforks at me because

of that statement. But, you know, we're not talking about just 24 athletes. I mean, this has been proven over and over again with hundreds of thousands of folks on our platform. So it's kind of interesting. And what's exciting about that knowledge is that athletes actually have way more control than they realize, right? If they understand what to pay attention to and how to think about their sleep and their hydration and, you know, their fueling strategies and, you know, and how to really take stock in the most important psychological needs that we have and build an infrastructure around that, you know, on a daily basis, like you can start to really control your performance levels, you know, and show up with a level of capacity that enables

you to do your best work. Yeah. So that's, that's really, you know, kind of this whole excursion and kind of understanding the factors that influence performance kind of this whole excursion and kind of understanding the factors that influence performance kind of led me to Whoop because that was really what Whoop was trying to solve. And we were kind of trying to solve it at the same time. And that's where I met the CEO of Whoop and I decided to join forces. So yeah, that's kind of what led me to Whoop. Amazing. And I love the emphasis as well on recovery. I do completely agree with you there. I think for some people listening, they're not going to fully understand what a Whoop is and how it differs to kind of other wearables on the market. So can you kind

of just briefly summarize what the purpose of a WhoP is versus say a standard fitness tracker, a smart watch? Yeah. You know, WHOOP really at our core, we're a data and analytics company. So we take all of these biomarkers and transform them to give you insight into how your body is responding and adapting to external stress. And we measure that in the form of whoop recovery. So whoop recovery is on a scale of zero to 100. And it basically gives you an indication, again, of how you're adapting to external stress. We also measure sleep, and we go really deep on sleep. I think we're probably the most accurate wearable out there in terms of our ability to not just understand when you're asleep and when you're awake, but actually how much time you're

spending in the various stages of sleep, and then be able to coach you to a better future. And then strain, it's a summary statistic of your cardiovascular load. So I think what's important with strain is that we tell you not just what you're doing during your workout, but what's happening over the course of the day. So, you know, more of a cardiovascular picture of what you're doing to your body, as opposed to just steps, for example, which is really arbitrary and doesn't really give us a whole lot of insight. You know, and I think that's one of the core differentiators of whoop is really this, this cardiovascular picture, which I think is really important. And then be able to compare, you know, fitness levels over time and kind of how you, you know,

if your walk today, what that looks like cardiovascular versus your walk in three weeks, you know, you can kind of compare and contrast. So really it's a 24 seven physiological monitor during device, you know, that looks at strain sleep and recovery on a continuous basis., it's a 24-7 physiological monitoring device, you know, that looks at strain, sleep, and recovery on a continuous basis. So it's a 24-7 tracker. It's designed to be worn 24-7. You don't have to take it off. The battery just slides over top, so you never have to take it off to charge it.

So you're literally getting kind of this really robust 24-7 picture. And then I think just like the signal accuracy, which I always feel like I have to call out. I mean, anything that you're wearing on your wrist, the raw signal quality, or even on a ring, the raw signal quality can be quite noisy. So I think we've developed a set of really sophisticated algorithms that take this signal in almost any condition and can filter out the noise sources really, really accurately. So I think we're giving you a really accurate picture of what's actually happening physiologically. Absolutely. And I mean, I was so impressed with the amount of data and the insights that you can get from it. Because prior to myself investing in a whoop a lot of my friends were wearing them and

I didn't fully understand if I'm completely honest like what the the big appeal was until I actually started using it myself and then realized how it was starting to shape my health behaviors. Sleep comes to mind as one of the biggest things that it's changed for me especially when you can input in your daily journal the things that kind of you did the night before and how that impacted your sleep and then getting your data set at the end of the month and you're like wow wearing a sleep mask improves my sleep and like reading before I go to bed and it's really interesting yeah the. The behavior modification piece is definitely a core differentiator. There's no question. And we see this across every population we work with,

from corporate executives to frontline healthcare workers to professional athletes. I think putting these data, data that are consumable and actionable in the hands of the individual is really the other insight that I learned from coaching is that, you know, me trying to prescribe, you know, these behaviors and get my athletes to do them on a consistent basis was really hard. But when they start to see the performance cost of specific behaviors, for example, what is, you know, drinking alcohol really do to my sleep? What does it really do to my recovery? And be able to see that in black and white, I think is really a powerful forcing function for change. So yeah, we do see this across all populations.

Absolutely. And you mentioned some interesting research that you guys are doing at the moment. And I know kind of from the regular emails that go out in the Whoop newsletter that you're constantly doing research and really interesting research. Can you share any perhaps case studies or some of the most recent stuff that you guys have been doing? Yeah, I mean, I think, you know, we're a product that takes a lot of pride being grounded in science. So all of the algorithms that we have are based on tons of existing research. And then it's supplemented by our own insights, you know, just looking at our member data, and, you know, huge, you know, millions and millions and millions of sleeps, you know, so we have just these incredible robust data sets that we're able to use to train our algorithms and become more accurate. So,

so I think, you know, some of the research that I'm involved in right now is there's very little published data that validates the link between, you know, kind of emotional states, motivational profiles and emotion, you know, regulation with real time physiological data, you know, outside a lab. So kind of taking, you know, whoop and putting it on the wrist and then being able to see what's happening cardiovascularly and how that might be linked to certain emotional states is, is really valuable, right? Because we know that there's this powerful link between the psychology and the physiology, but we don't necessarily understand what that interplay really looks like and how our behaviors

are actually informing the strength and resilience of that link or the direction of that link. So that's a lot of the research that we're involved in right now. And we're definitely seeing some behaviors that are surfacing that actually predict resilience. So one of the recent findings is sleep consistency has really bubbled to the surface as the behavior that predicts cardiovascular resilience as measured by heart variability and resting heart rate. And this is looking at a massive data set. We're talking thousands and thousands of folks. And the study design was basically looking at member data pre-pandemic. And then once the lockdown hit, the data post, so three months before, three months after, and we were looking

for kind of, you know, what is the signature that most predicts physiological resilience? And what bubbled to the surface was sleep consistency. So the degree to which you stabilize when you go to bed and when you wake up. And this obviously makes a whole lot of sense, you know, as if we think about our circadian rhythm and, you know, our sleep, how it's obviously modulated by our interaction with day and night. And again, you know, when we go to bed and when we wake up is truly influences the degree to which our systems are able to function at our most efficient levels. So it's not surprising, but it was really cool to kind of see this unequivocally surface as the most important behavior. So that's one finding that I think was really, really interesting.

Yeah, really fascinating. And we keep mentioning recovery and things like HRV. How exactly does WHOOP calculate recovery? What are the kind of metrics it's based on? Yeah. So our recovery algorithm takes heart rate variability, rest and heart rate, and we take those values during the night. So when conditions are most stable and most consistent, and then we look at respiratory rate also during the night. And that's just kind of a summary statistic over the course of, we take every breath over the course of your sleep and then average that. And we use your respiratory rate in our algorithm and then your sleep performance.

So that kind of makes up our WHOOP recovery kind of algorithm. And recovery is really a concept of autonomic nervous system adaptation, you know, which incorporates all the inputs that I just mentioned. So yeah, that's kind of how we think about WUP recovery. Yeah. And heart rate variability, I feel like is getting a lot of airtime recently. Like we're really, a lot of different kind of organizations are using it. It wasn't something that was focused on as much before. How can we improve our heart rate variability? Yeah. And obviously it makes me wildly happy,

so happy that heart rate variability is being taken more seriously and people are starting to focus on it because it really is, it's a measure of your autonomic nervous system and it's really considered the best objective metric to understand your physical and mental readiness, which is important. I, you know, for, for a lot of reasons, but I think if you're going to focus on one metric, you know, heart rate variability is, is just gives you a really great snapshot of, of just how you're adapting to all the stressors in your life, again, both physical and mental. I think it's just important to understand. And again, it's just one of the inputs into our recovery algorithm, but we do weight at the heaviest of the four inputs.

And there's a lot of physiological reasons why we do that. And the research has shown too, when you do pay attention to it, your health actually improves. So it's a really good marker to pay attention to. And I think some of the core things that influence your heart rate variability is one, just how you're managing stress throughout the day and being really proactive and paying attention to the balance between kind of stress and rest. Stress in of itself is not bad. And obviously it's really important for us to all take on stress, right? To build resilience and, you know, to get stuff done.

You know, when we feel stressed, it's usually just our body sending us a signal that it's time to take action. So that's not necessarily a bad thing, but we also need to have tools to understand how to deactivate, right? Chronic activation is what leads to kind understand how to deactivate, right? Chronic activation is what leads to kind of chronic stress and burnout, right? And I think one of the best ways to create autonomic balance, right, which is what HRV will be a measure of either imbalance or balance and a higher HRV means there's balance. And, you know, controlling and, you know, stress

throughout the day is one of those ways to really mediate heart variability. Some intentional breathing, the most efficacious is a technique called resonance frequency breathing, which basically just maps your respiratory rate and heart rate in a frequency that is optimal for you. Most adults are kind of at 6.0, I think, breast per minute, but the range is going to vary slightly. But residence frequency breathing has emerged in literature as the most efficacious in mediating heart rate variability. So that would be one to pay attention to. I think generally just breathing through your nose throughout the day, as opposed

to out your mouth is also a way to really help heart rate variability. And it sounds so simple, but I think most people aren't necessarily focused on their breath, but there's a lot of research out there as well that points to nasal breathing as being really efficacious to kind of helping stabilize our autonomic nervous system. And also helps with sleep. And sleep is the other one that will definitely influence your heart rate variability. And again, if you can focus on that stabilizing that sleep wake timing, we know that that correlates to, you know, next day heart rate variability. So, you know, sleep consistency and the quality of your sleep, obviously,

and actually sleep consistency drives sleep quality. Again, both will influence your heart rate variability. And then I think the other thing that's really core is just the timing of the meals. We see this in the data. And there's a lot of good literature out there that suggests we should bias toward earlier in the day. And I think for listeners, to make it real simple, you know, try to eat when the sun is out, and try to not eat when the when the sun goes down, because I think most folks probably don't realize this, but, you know, weight gain and obesity is really hormonal, which suggests that it's aligned with our circadian rhythm. So and again, this kind

of pull toward like lightness and darkness and being able to align our behavior. So we're in sync with kind of the natural cues in our environment, you know, obviously have evolutionary roots, but something that people can grasp onto that will really have a profound impact on, on recovery and, and HRV. So sleep timing is, is quite massive. So those are a few things. Maybe I mentioned one more that also relates to circadian rhythm and has a profound influence on when you actually feel sleepy. So this will enable you to have consistent sleep time. And that is one of the most important behaviors that kind of toggle onto that is viewing light in the morning. So, and again,

most things I'm mentioning here are democratically available, right? Like they're free. So it's just a matter of being disciplined about them, but viewing light within 20 minutes of waking up prior to 9am, even if it's cloudy, that photon energy from the sun is, is really central and kind of setting our, our circadian clock. It's basically that getting outside again, you know, within 20 minutes of waking up prior to 9am, you know, for five to 10 minutes, we'll give you the photon energy you need for your body to then know that it's time to be alert. It's really important to get that cortisol pulse going and to tell your body that it's time to be awake.

And then that starts, you know, the clock on, okay, I'm supposed to be awake. And then 12 hours later, we'll be building pressure throughout the day. And then that will lead to a point where you actually start to feel sleepy at night. But that first moment of sun is really going to be the precursor that kicks all of all of that off. Absolutely. One of the things you mentioned, obviously, is meal timing. And I guess nutrition as a whole is really important when it comes to recovery. Do you think that nutrition will be integrated into the app at any point? Yeah, I mean, I'd love, you know, baby steps, I think, for me, just given the research that exists out there, I really want to help folks think about the timing of their meals first. You know, so when we think about what the

order of operation, get the meal timing right. And I know this isn't going to be perfect every day, but if you can, you know, four of the seven days, you know, eat when the sun's out and not eat when the sun's down, you know, you'll really, really be helping yourself. And like, obviously, we've spoken quite extensively about recovery. But one of the things that I wanted to ask you is whether you have gained any insights into kind of sex and gender differences when it comes to recovery from the data that you guys have collected? Or is that something that's not really being looked at yet? Oh, yeah, no, we're definitely we're actually we have a paper in peer review right now that looks

at people identify as men and folks who identify as women and what those differences, how those differences manifest in whoop recovery and how they build strain. You know, I can't talk specifically, but there are massive differences and they all, they definitely fluctuate with hormone cycles of women. So, you know, we definitely, you know, have very different, and this is relatively, you know, well-documented, but, you know, different phases of our cycle, we're going to be more adept at, you know, certain types of workouts, for example, and might need different Wild AI, you know, there's lots of, I think, you know, technologies that are trying to help females in particular better understand how their cycle influences their capacity to take on volume and intensity and what that actually

means for recovery. And what's cool about what we're doing is we're actually able to quantify all of that. So it's a lot less active input by the user. We can actually passively collect all this data and then be able to give you recommendations without a lot of, you know, user interaction, which is, which is really cool. So we're building toward that. That's coming. What we do currently have is we have a sleep coach feature based on where you're at in your menstrual cycle. So one of the things that we saw in our data is that your sleep efficiency absolutely varies by your menstrual cycle phase. So people who menstruate will definitely need to allow more time in bed during the luteal phase to offset the reduced efficiency. So for example, if a female member typically spends 7.5

hours of sleep in an eight hour sleep opportunity, that member would want to give herself 8.25 hours to get the same 7.5 hours in order to kind of feel your best. And what's cool is that WHOOP does all of this adjusting for you. You don't need to even think about it, all you need to do is just listen to whoop sleep need recommendation, and it will automatically, you know, kind of adjust how much time you need to be spending in bed, which is really cool. And I have another cool, like super cool finding that just came out around sleep need recommendations, and how they correlate to executive functioning and working memory, if you want me to reveal that. Okay. And this is, again, you know, a lot of the research, just understanding,

you know, emotion regulation and, you know, some of these things that are a little bit less abstract and less tied to the physiology and really trying to unpack this. And this one is related to kind of cognitive measures, looking at executive functioning and working memory. We just call these, I guess, for lack of a better word, these are performance data, executive functioning, working memory. We measured them via Stroop and MBAC over the course of a six-month study. And what we saw is such a strong p-value. It's almost a causal relationship between the sleep debt that folks accumulate, predict. So the more sleep debt, the worse they performed on the NBAC and the Stroop next day. So sleep debt is a metric that we reveal, we surface to our users to help them understand what they needed to

get for sleep. So how much time whoop told them to spend in bed versus what they actually got. That delta shows up as your sleep debt and it accumulates over the course of the days. So you can start to see an accumulation of sleep debt if you're missing your sleep need. Okay. And I can talk how this actually relates to illness and injury burden and availability in sports. There's some separate research we've done looking at that, which is fascinating. But this one little metric of sleep debt predicted executive functioning and working memory.

So literally, if you keep your sleep debt below 30 minutes, your cognitive functioning is going to be far superior than if you allow this sleep debt to accrue. And we see as much as 40 minutes of sleep debt will impact your next day working memory and executive function. Wow. So it basically, because your sleep debt is an input to your sleep need recommendation, right? So we take your baseline, we take any naps you took, we take your sleep debt and your strain. So how much cardiovascular load you've accrued.

So we take those four inputs and we use that to give you a sleep need recommendation. So a lot of the sleep scientists come at me like your sleep need is just totally made up. And obviously it's based on a ton of physiology and a lot of external research. And we've kind of fit it to our ecosystem. But this sleep debt, you know, the fact that sleep debt correlates so like, literally almost like it's such a strong relationship. We basically indirectly validated our sleep need recommendation. So if you literally listen to whoop, sleep need recommendations, you will show up tomorrow with more availability, not just physically, but mentally as well. That's amazing. Yeah. And so if you, can you make that up by napping the next day,

if you've had a poor night's sleep? Yes. So can, and that is really the protocol. So when we're working with elite teams and corporate executives, I mean, anyone who's interested in kind of performing at the, at the highest level, you know, we know that there's this relationship between executive function or illness and injury burden also correlate to sleep debt. So if you, if you wake up with, you know, 30 minutes of sleep debt, for example, the recommendation a hundred percent is to, to map that sleep debt with a nap. So generally speaking, you know, keep it to an ultradian cycle, so nothing more than 90 minutes, but that is definitely the recommendation. So you can't make up for, you know, kind of lost biological sleep necessarily,

but you can definitely buffer the impact by incorporating a nap during the day. Again, make sure it's prior to 2pm. You know, anything after that is going to have actually a deleterious effect on on next day sleep and could potentially impact your kind of nocturnal sleep experience. And also could delay your sleep onset latency, which you know how fast it takes for you to fall asleep. So you want to be careful about when you nap, but that is 100% the recommendation to keep sleep debt at bay is to use naps strategically. Absolutely. And so you mentioned sleep debt and injury and illness.

Can you speak to that a little bit and what you've learned there? Yeah. So I always, you know, obviously I'm a coach for 17 years, so it's all about availability, right? Like you're doing everything you can to make your athletes, you know, obviously I'm a coach for 17 years, so it's all about availability, right? Like you're doing everything you can to make your athletes, you know, ensure that your athletes are available for training. And, you know, a lot of that does in fact have to do with, you know, the volume and intensity, but generally speaking in elite level athletes, nothing you can really do

in a two hour training session is going to injure them, right? If they are coming to your training session with capacity, right? And the way to come with capacity is to meet your sleep need, most simply. And we saw this in a study that we did with 230 collegiate student athletes. And basically the sleep debt, again, the folks who kept sleep debt below 30 minutes, not one of them actually got injured, which is insane, right? And obviously there's luck involved in that clearly, but most importantly, over the six month period, no one gets sick. So sleep debt, if again, you keep it under 30 minutes, you're really positioning yourself to

be illness and injury proof. Wow. I know. It's crazy. And I think, too, when we consider availability and what that predicts in team sports, there's some really cool research around that. I think Ray Smith and colleagues, it was basically looking at performance success or failure and how that's influenced by weeks lost to injury and illness. And I think this was in track and field athletes, but it was a, it was a five-year prospective study. So it was like a long study. Then they basically saw that by lowering illness and injury burden, it enabled athletes to complete the

prescribed training. And this availability basically was more likely 10 times more likely for the team to optimize its individual and therefore its team potential. So it basically the formula explained 86% of successful seasons. So it's, you know, it seems probably obvious, but, but I think what's so cool about this is it's again, it's understanding how to apply your effort, right? Like I want to be able to tell my athlete, you know, one thing that they can do. If they literally keep their sleep debt below 30 minutes, and that's the only thing that you focus on. And if that's the anchor, right, like that is going to, it's going to influence really all the behaviors, right?

Because in order to keep your sleep debt below 30 minutes, that means you have to limit the time awake. You have to actually get quality sleep. You'd have to go to bed and wake up at consistent time. So you can start to back into these other behaviors that are really central, but it's measured like how well you're doing these other things is basically you can kind of quantify it in in the sleep debt metric yeah and a lot more people are giving sleep as well more attention and i guess with the likes of why we sleep and books like that like you know everyone's we're realizing it's a lot more important than we previously thought for performance physical health mental health like it is literally the greatest and and dr matthew walker you reference why we sleep, which is brilliant. And as a sleep evangelist, I just have so much gratitude for this man and kind of what he's done, you know, to just evangelize this concept. Cause I, you know, we think about root cause mortality, it's insufficient sleep, right? You know, when we think about cardiovascular

disease and, you know, and I think he makes the case in the book of why, you know, insufficient sleep is root cause to all mortality. And I, and I, so I think if we're, if we're not thinking about sleep and figuring out how to get the best possible sleep, then we're, you know, really doing ourselves a huge disservice, right? Cause it, you know, how we sleep really determines how we show up. And yeah, I mean,thew walker has just really been so helpful and getting that out to the forefront yeah and making it so accessible but i guess you know i feel like there's a everyone's a sleep expert now and there's there's things that that are very much common sense when it comes to getting a good night's sleep. But then, like, obviously, you guys are collecting data all the time from people who are inputting into their sleep journals

and then kind of applying that to how much sleep and how good quality and deep sleep they're getting. So what are kind of the fundamental things that you found that are really important for not just quantity, but quality of sleep? Yeah. So there's really, there there's quantity, there's quality and there's a consistency, right? So those are kind of the three pillars of sleep. And I think the biggest behavior that influences your potential for quality sleep is the degree to which you stabilize your sleep wake timing, right? So I kind of been talking about that throughout the podcast. If your project is to

get better sleep, start with stabilizing your sleep wake timing. So just try to make that as regular as humanly possible. And in order to have a regular sleep wake timing, one of the other like kind of most important behaviors is really getting that sunlight exposure within 20 minutes of waking up. And these are things that I don't know that people think about a whole lot. And then watching the sun set at night, that's basically going to tell your body to deactivate and that, oh, it's time for sleep, right? So you're sending signals to your body that, okay, it's time to wind down.

It's time to get some sleep. And then I think the kind of the next piece to that is, all right, how are you phasing into the evening? You want to make sure that you're not exposing yourself to tons of artificial light. Because again, when your eyeballs see that light, it signals to the brain again, that it's time to be awake. So to get a quality night's sleep, you'd want to try to help your body understand what it needs to do next. So, you know, limit the artificial light exposure, you know, to the degree that you can make your bedroom as cool as possible

and then snuggle up with warm blankets. And I know not everyone has the privilege of having, you know, air condition in their home and can't keep their room at 64 degrees. But to the degree that you can try to keep your room cool, dark, quiet, those will also impact your sleep quality. And then again, meal timing. And just what's happening mechanistically here is that if you eat a lot of food, once the sun goes down and close to bedtime, all of the resources that typically would go toward helping you, you know, get quality sleep, which is basically measured by how much time you're spending in these deeper stages of sleep. But what happens when you eat close to bedtime is you divert resources toward digestion. Because sleep and digestion are both parasympathetic activities. You can't do both at the same time. And your body will prefer to digest food before it will sleep, but it just has to, right? It doesn't have a choice. So it

has to take care of the stuff in your belly before it can focus on sleep. So I think that's really important for folks to understand if, again, they want to get quality sleep. And we see meals close to bedtime is one of the top influencers on next day recovery. And that's one of the things, to your point, we get to track in the journal is when you're eating your meals. And we're seeing the surface in a study that we're doing with 700 collegiate athletes as well, looking at pre-bed meal timing seems to have a relationship to heart variability. So again, I think really important. And then alcohol is probably the other behavior. Because alcohol is a sedative, you might feel like you're sleeping, but the reason why after you drink alcohol,

you wake up feeling really crappy and not refreshed is because you're spending no time in deeper stages of sleep. Your heart rate is usually jacked. Your heart rate variability is suppressed. So your respiratory rate is higher. So all the makings of a not restful nighttime experience. Gosh, I feel like alcohol has the biggest influence on my recovery when it comes to

the only time I got red recovery is if I've had a drink the night before. I know. I know. It's really kind of depressing. But yeah, I mean, sometimes our members will see, you know, one glass of wine and they'll wake up with a better recovery the next day than, than maybe they typically have. And, and actually there is like a kind of a sweet spot. I think like, um, you know, alcohol has some real positive effects depending on what kind

of alcohol you drink, of course, but one glass of wine, you know, with friends, you know, around a meal, like it's like kind of the social connection that happens can actually have a real positive effect on your psychology. And as we know, you know, your psychology influences your physiology and vice versa. Yeah. So it doesn't mean you can't have alcohol, but it's just about being smart about the timing and just making sure that you're hydrating appropriately. You know, having water is important. So, yeah. Absolutely. about being smart about the timing and just making sure that you're hydrating appropriately you know having water is important so absolutely and I guess circling back to kind of the shaping behavior I'm sure for people who are like top level athletes and using devices like this to like

track the recovery and if they're seeing that in real time that like it's really negatively impacting their performance scores it's going to deter them from doing having a big night out you know close to a big event or when they're in a hard training season totally i mean we see and this has been just the coolest thing to observe in the time that i've been at whoop which which gosh, now it's like five years, is that across every single cohort we work with, especially in these high stakes environments where deactivation is difficult. And when you look at frontline healthcare workers and tactical athletes and professional athletes who come off of these really high stress kind of jobs. And if they don't have the tools to understand how to deactivate, oftentimes they use alcohol to help them come down. And we

see that over the course of the time on the platform, these folks in these high stake and verticals on average reduce their alcohol consumption by 89%. Oh my God. I know, which is like, I know we can't see each other, but I'm smiling, you know, just because, you know, I just Oh my God. the day. I think that's all we're after. And not to paint this horrible picture around alcohol, but it does impact us and it has a profound impact on our ability to kind of show up for the people that we love and for the things that we love. So to be able to kind of quantify that in such an elegant way and be able to display that to our members, I think is a real contribution, I think, to humanity really. So yeah's I'm really proud of the fact that we have a product that's able to modify behavior in such a profound way.

Yeah, I completely agree. It's, it's really, really useful. And definitely, like, you know, changing how people perform and, and health outcomes. And I guess, we've talked extensively about sleep. And so I imagine that you're going to put that right up there with your kind of recovery strategies. But what would you say are the kind of maybe top three most impactful changes that you think people can start today to improve their performance and day to day health? Yeah, no, I mean, I mean, definitely the stuff that we've talked about, right, stabilizing sleepizing sleep, awake timing, again, the most important behavior. So getting outside in the morning while the sun, and then while the sun's setting,

eat when the sun's out, those are huge. I think the other things that, that really influence, you know, recovery, having a contemplative practice has been shown, you know, in the literature to be really powerful, either gratitude journaling shown, you know, in the literature to be really powerful, either gratitude journaling, or, you know, mindfulness meditation, really, I think, you know, just being able to control your attention. So you can attend to the things that matter. And you can kind of find the signal through all the noise that's out there. I think, you know, mindfulness meditation, gratitude journaling is kind of a path to that. And then I mentioned the biofeedback,

the resonance frequency breathing. Hydration is so simple, but dehydration compromises your ability to recover in just profound ways. So staying hydrated is so critical. And generally speaking, I think from a protocol standpoint, you know, you want to point if you're not training a ton, you know, point five ounces to every pound of body weight would be a good place to start. I think you can definitely

overhydrate. So you just want to, you know, monitor your levels. So anyway, hydration is really key. Mobility is another thing that I think is probably not talked about enough. But I think if you look at the literature, you know, how mobile you are later in life, you know, definitely influences, you know, your health and your wellness and your longevity and staving off disease. And so staying mobile, I think is really important. And then some sort of like cold kind of hot therapy, you know, and basically what I'm talking about, if you distill recovery down to either activating the parasympathetic state, so you're either calming your nervous system, or you're activating the sympathetic, you're activating your nervous system, right? So it's really recovery is about strategically activating

and deactivating your autonomic nervous system. So a lot of what I have talked about so far related to kind of HRV biofeedback, contemplative practice, hydration, mobility are all parasympathetic activities. I think cold and hot therapy actually activate the sympathetic branch of the nervous system, which also is important, right? Because it's always about this balance. But you know, cold and hot are going to temporarily suppress heart variability and increase resting heart rate. But these practices lead to higher levels of resilience over time. So it definitely improves cardiovascular functioning, cognitive functioning, it's been proven in the literature. So when we think about, you know, recovery behavior, generally, mobility, hydration, cold, hot therapy, some sort of HRB, the biofeedback, I talked about resonance frequency breathing, and a contemplative practice

would be kind of my top ones. And this is based on just the oceans of science and literature that exist out there, I've kind of wrestled it to the ground. And those are the top things that I would be tracking. I want to circle back to gratitude. And have you noticed from the data that that is has a tangible difference on people's recovery? Not in our data, per se. You know, people at a like at a population level that hasn't surfaced in our data. But there is a lot of external research, you know, really well done controlled studies that suggest that contemplative practice. So specifically a lot of research around gratitude, journaling and meditation and mindfulness seem to be linked to better mental health, which better mental health will lead to better physiological

functioning generally, right? There's bi-directional kind of nature. So yeah, there's a lot of external literature, we don't necessarily see that manifest in our data, per se. But yeah, it's definitely worth, I think, mentioning and putting it in kind of the top six of recovery behaviors that are associated with optimal biometric outcomes. Yeah, absolutely. And I think also, especially if you're doing it like pre bedtime, it's like a journaling practice, a wind down, it's part of your routine, it switches you off, there's so many kind of indirect benefits when it comes to performance and recovery. There's no doubt. And I think it's probably worth mentioning, like I, it's hard, it is hard to study because it's it's actually quite nonspecific, right? Like I, you know, if I were to tell you to do

one thing, I probably say to do resonance frequency breathing in terms of an order of operation. Cause I think it's, that incorporates the breath and doing it at a specific frequency. Whereas meditation and mindfulness is really a skill you need to develop and get good at. That said, I think just sitting quietly and just doing your best to be mindful of your breath and keep your thoughts at bay is absolutely worth doing every day, but it is a bit harder for people. So I think if you're looking to grasp onto a behavior

that can really have immediate impact on recovery, residence frequency breathing is kind of the first thing to potentially do. Again, if we're talking about, you know, we've mentioned six things, what is the order of operation? I would put kind of residence frequency at the top. And then I think to your point, like doing some journaling at night, generally speaking, should help kind of calm the mind. And then ending that journal, you know, listing three things that you're really grateful for tend to kind of position you to have a good night's sleep. Amazing. So many takeaways there. That was such a fascinating conversation. I hope so. Yeah, absolutely. Well, thank you for giving us your

time today. It's a pleasure. I know it's kind of a lot of information. But yeah, I always feel like, you know, I think we want to spend less time on these things, not more time. And, and I think it's a lot of the research that we're doing is try to, again, find that signal amidst all the noise. So people understand how to apply their effort and can, you know, can build practices that really do help them get on with their life, you know? Yeah, 100%. And so if people want to learn more about the research that you're doing or the work that you're personally doing do you have are you present on social media the the locker at our whoop.com website you know we'll write about and podcast on all the recent research the executive function study i i referenced we we actually just did a

podcast on so um if you go to whoop.com, you hit the locker. There basically is all of our articles, articles about the research that we're doing and then all the podcasts as well. I do not have like a huge social media following, but I do post on Instagram, about a lot of the stuff that I'm talking about today. It's Kristen underscore Holmes, 2126.

And then I'm more active on LinkedIn. So always will post about new research. And I try to really help folks understand, you know, what the research means and how they apply it to their lives. And also, I always outline what the limitations are of the research, too, so people can take it with a grain of salt and understand how they might apply it to their lives. And also I always outline what the limitations are of the research too, so people can take it with a grain of salt and understand how they might apply it in the real world. Amazing.

Well, thank you so much again. And I hope you have a lovely rest of your day. Okay, team, that was Kristen. I hope you enjoyed the podcast as much as I did. I just loved diving a bit deeper into the science around wearable technology and learning more about how we can use devices like Whoop to really enhance our recovery and performance. If you love this episode, you know the drill, leave a rating, leave a review, and we'll see you again next time