WHOOP Podcast - Listener Questions with Emily Capodilupo: HRV, Fasting, and the Impact of Vices on Performances

Episode Date: June 28, 2023

This week on the WHOOP Podcast, we’re diving back into the inbox to answer questions from our listeners. From the impact of sleep on HRV, detecting mental and physical stress, time-restricted eating and fasting, to the impact of THC and alcohol on the body, we’re tackling it all with none other than SVP of Data Science & Research Emily Capodilupo. Emily breaks down the correlation between sleep and HRV (2:30), the impact of alcohol and marijuana on performance and recovery (4:45), the process of tracking nicotine usage and its effects on recovery (10:20), how to detect different types of stress with the Stress Monitor feature (13:45), and the difference between time-restricted eating and intermittent fasting (16:50).Resources:WHOOP Stress StudySupport the showFollow WHOOP: www.whoop.com Trial WHOOP for Free Instagram TikTok YouTube X Facebook LinkedIn Follow Will Ahmed: Instagram X LinkedIn Follow Kristen Holmes: Instagram LinkedIn Follow Emily Capodilupo: LinkedIn

What's up, folks? Welcome back to the WOOP podcast where we sit down with the best of the best to learn what the best in the world are doing to perform at their peak and what you can do to unlock your own best performance. I'm your host, Will Ahmed, founder and CEO of WOOP, and we're on a mission to unlock human performance. This week we're diving back into the inbox. That's right.

Every week we ask you to ask us questions. You are great listeners, and we've got plenty answered. From the impact of sleep on HRV, detecting mental and physical stress, time-restricted eating and fasting, the impact of THC and alcohol, that's right, we're tackling it all with none other than SVP of data science and research, the fearless Emily Capital Lupo. Emily joins us to cover the correlation between deep sleep and HRV, the impact of alcohol and marijuana on performance and recovery, tracking nicotine usage and its impact on recovery compared to tobacco, that's an interesting nuance, detecting different types of stress with the stress monitor feature, and the differences between time-restricted eating and intermittent fasting. With the 4th of July right around the corner, it's time to cue the fireworks. That's right. The new Freedom Band is here. Designed in the ultimate seasonal colors, red, white, and blue.

The Freedom Band is ready for the beach, barbecues, and all of the celebrations that Summer has in store. Grab yours in the Whoop shop today. If you're looking to join Whoop, new members can use the code Will at checkout, get a $60 credit on apparel and accessories. That's bands, battery packs, and more. That's the code will, $60 credit when you sign up. If you have any questions you want to see answered on the podcast, much like this podcast, email us, podcast at whoop.com, call us 508-443-4952, and it might just be answered on a future episode. Without further ado, here is Emily Capital Lupo. Hey, everybody. This is Emily Capital Lupo, SVP of data science and research at Woop.

here to answer some really fun questions submitted by you guys, our listeners. First up, we have a question about sleep and recovery. The question was, I've been listening to and reading your podcast and research on HRV. I notice that generally I'll be green recovered after even pretty poor sleep, and often my HRV is high then. This is a really common question that we get about the relationship between HRV and sleep. And while those things are generally pretty correlated, there's a reason why we have two separate scores. HRV measures your body's readiness to take on different kinds of physiological challenges. The best thing you can do to boost your HRV is to get a good night's sleep.

It's one of the most powerful things under your control to influence your HRV the next day. But HRV is going to respond to a lot more than how you slept. some extreme examples that will make this a little bit easier to understand. Think about the last time you were sick. You probably slept 12, 16 hours and you don't wake up feeling refreshed, right? So that's an example where lots and lots of sleep likely going to be associated with a very poor or very low HRV. What this listener was asking about was the opposite. They were saying, I slept poorly. How is it possible that my HRV was good? And for that to happen, typically lots of other things need to be conspiring for the positive. And so if enough good things are going on, that can really outweigh

one bad night of sleep. We especially see this with somebody who's had a string of really good sleep, so they're going into that night of poor sleep, you're relatively well rested. And we also see this when the reason why you're poorly rested is positive. So we've seen huge boost to HRV associated with like good mood and you kind of doing things that feel good and are good for the soul for lack of a better word. So we see people go and have like a night out with their friends. And that can be so restorative that it can compensate for the relative, you know, the shorter period of sleep that tends to follow. Obviously that's within reason. If you keep doing those short sleeps night after night, your HIV is going to reflect that. But if you do enough good things, you can

compensate for one bad thing, even if that bad thing is something so big and important like sleep. Our next question comes from Thomas with a similar one from Deanna, so I'm going to read them both and then answer them together. So Thomas asks, Thomas is asking about the impact of marijuana on recovery. He says, since quantifying how much alcohol affects my sleep, I've gone from three to four beers a day to drinking only once or twice a month. The impact on my recovery has been astounding, and I wouldn't have made the change, if not for all, that y'all do in recovery research. My wife, on the other hand, defaults to THC to self-soothed before bed on an almost daily basis. Since tracking THC is an option in the journal, we were wondering if y'all have any

data on how this affects recovery scores for the average whoop user. Thanks again for being pioneers on performance. And then Deanna's similar question, exploring some training and performance metrics. She wants to know what the impact of marijuana is on performance. First off, for Thomas, you know, definitely exciting to see that he's cut back on alcohol. And, you know, that's a story that we hear a lot that as soon as you start to see what it's really doing to your body, the way that Lou quantifies it, becomes really hard to keep those bad habits going. But to answer the question that they're both asking with regards to THC or marijuana, just backing up for a quick second for people who aren't familiar. Marijuana has two active compounds, THC, which is generally what we think of as the

one that makes you high, and CBD, which is popular in all kinds of different wellness products because it's anti-inflammatory and it doesn't have any of those, the quote-unquote like drug, it doesn't make you high or anything like that. But these listeners are asking about marijuana and THC, so we're going to focus on the THC side. It's a little bit complicated to lump these together, even though the THC, you can get THC outside of marijuana in all kinds of different isolated products, because when it comes to marijuana, you're often consuming it by smoking, and the smoking part can have all kinds of negative effects separate from the effect of the THC itself. You know, anytime you're smoking anything, you're getting exposed to a certain

amount of carbon monoxide, which is dangerous. You're getting, you know, all kinds of things like tar in your lungs and the effect on your lungs and how your body responds and sort of the inflammation that follows is going to have a negative effect on things like sleep and recovery. But if we just focus on the part from the THC itself, there's some interesting data. So first off, who is using marijuana? We mostly see that people in their 30s on whoop are most likely to be using marijuana and slightly more males than females receive out 11% of males and 9% of females. on whoops. This is an important topic. It affects a lot of people. So let's jump into it. We see that,

you know, not surprisingly, heart rate variability is a little bit lower for people using marijuana than when those same people don't use it or don't report using it. And similarly, resting heart rate is slightly elevated. Both of these effects are relatively minor. We're talking about a three millisecond hit to HRV and about a one BPM increase to resting heart rate. We also see a decrease in restorative sleep, particularly REM sleep, is affected by marijuana use. And then all of these hits kind of boil down to a modest decrease in recovery, roughly about 2.5% lower than usual. We also see that people tend to get a little bit more sleep. It's hard to know what the causal relationship is here.

If people are smoking on nights when they say they don't have to get up and work the next day, so they might be sleeping in, versus if they're getting more. sleep because the marijuana itself is helping them sleep. A lot of people find that using either marijuana or a THD helps them fall asleep. And that does seem to be supported by the literature, but this is somewhat counteracted by the fact that the quality of the sleep is a little bit lower, as seen by the slight reduction in restorative sleep and particularly the reduction of REM sleep. It's interesting to think about when you look at this data, what that might mean for you. So REM sleep is the mentally restorative part of sleep. It's when we convert information that we learn during the day from short to long-term memory.

And so you might be listening to these effects and saying like, oh, the effect of marijuana or THC is relatively small. And that's not an unreasonable conclusion, but think about like how important is it that I like get my REM sleep tonight. If you didn't have a particularly important day, doesn't feel like you need to perform tomorrow. or the stuff that happened today is critical to convert from short to long-term memory. Is it a reasonable decision for a consenting adult to say, therefore, I want to do these things for a lot of people. The answer might be yes. But if you had a day that was kind of more important or tomorrow is important,

you want to make sure you get that REM sleep or that you maximize your chance of being recovered, you know, we do see, you know, these are statistically significant effects, even though the effect sizes are relatively small. And so you can think about, you know, whether or not. it makes sense for you in that moment based on your goals and if the benefit that you perceive that you're getting from indulging in these things is outweighed or not by the cost in terms of what you can expect for the next day. Our next question is in a similar vein. It comes from Chris. Chris wants to know how nicotine impacts recovery. And if there's a way to track that in the app.

So we don't actually directly track nicotine today, although thank you for the suggestion, Chris. probably something we should. We do track tobacco. And I said this when we were talking about marijuana just a few minutes ago, tobacco's active ingredient is nicotine. That's why it's addictive. Most people who are consuming tobacco, it's because they're looking for the effects of nicotine. But there's an important difference primarily in that nicotine can be isolated. And so you can get nicotine without tobaccos or all the smokeless vapes and different products like that. where you're not necessarily getting all the other chemicals that burning tobacco can put into your system so you don't get the same carbon monoxide exposure, for example. And so while we can learn a lot from the tobacco data that likely applies, at least to some degree, to the consumption of nicotine outside of tobacco, it's worth disclosing that what we generally know about from loop data is from tobacco and not from isolated nicotine.

That being said, we do know that nicotine, regardless of the form that you're consuming it in, has negative effects on sleep. And this comes in a couple of different places. Nicotine is a stimulant, and so it's going to suppress your feeling of tiredness. It's one of the reasons people like to have it. It's going to make it a lot harder to sleep. And then depending on how dependent you've become on nicotine and what your consumption patterns look like, you can actually start to go through withdrawal. And so nicotine withdrawal can wake you up in the middle of the night. And then you can end up in this vicious cycle where, you know, nicotine is a

stimulant. It makes it hard to fall asleep. When you finally do fall asleep, you go through withdrawal, which wakes you up in order to make that uncomfortable feeling go away. You know, you puff on your jewel. Well, now you just had another stimulant, so it's going to be harder to fall back asleep. And so, you know, the next morning you're tired, nicotine is a stimulant. It hides the feeling of being tired. You take more. And it becomes a really difficult pattern to break out of. And so we see, you know, a lot of times people who are habitual smokers or consumers of nicotine, regardless of the form, are going to have much worse sleep than the general population. And then we see people who aren't necessarily addicted, maybe just occasionally smoking when they go out, are using it because it helps them stay awake. And so then it's obviously going to be associated. with lower sleep and then lower sleep quality as we crash from the withdrawal and sort of physiologically respond to that. So there's been a tremendous amount of research done on tobacco use and increasingly more and more research coming out on nicotine use in general. But Chris, we appreciate the suggestion to track nicotine separate from tobacco. That's probably something

we should go and do. And then hopefully next time we can break down the loop data more directly and understand the effects of these two things independently. Our next question comes from Dominic. Dominic has been enjoying the new stress monitor feature and wants to learn more about the feature's capabilities. He asks, is the whoop able to detect additional stress or anxiety through the stress score during exercise or physical activity? Donna, great to hear that you are enjoying the stress monitor.

It's one of my favorite features too. and the short answer to your question is no in that we don't separate mental stress from physical stress in the stress score, but you are able to tease them out by understanding what you're doing and also by looking at similar activities over time. So after you've done, for example, like a couple of different runs, if you're all of a sudden running and experiencing a lot of mental stress, you'll see that the baseline that you've established for what a stress score during a run looks like might be lower than what you're seeing while you're experiencing mental stress and physical stress at the same time. And so you can sort of subtract out

that baseline and get a sense of if this feels particularly elevated or particularly high or normal or low. One of the reasons why we don't try and tease these things apart in the score is that physiologically stress is stress. And while stressors can feel like they come in a lot of different forms, at the end of the day, they do really mix together. And there's a huge gray area between like what's a physical stress and what's a mental stress because we tend to express our mental stresses physically. What we found in our research was that regardless of the source of the stress, our body responds to the stress pretty similarly. So we actually just had a paper published earlier this month in the journal Plus One, where we looked at

the physical responses in heart rate and heart rate variability to user-reported periods of high stress work, as well as to periods of running. So a pretty clear example of mental stress and physical stress. And what we found is really, really similar patterns that in response to either a physical stress or a mental stress, you see that during that stressful period, our stress scores would be high. And then in the time after, there's like a slow return to baseline. So you almost see similarly to like after you go for a really good run, it takes you a while to fully recover from that run for your body to cool off all of those things. We see that same pattern following high stress work. So emotional stress or a mental stressor. And so because

physiologically these things manifest in the same way. We express them in the same way in our stress score, but you can separate them out by looking at things like your strain score and your stress score. Our final question for today comes from Alia. Alia has been learning about different dietary and nutritional programs. Alia wants to know about the difference between time restricted eating and intermittent fasting. Also, if there's any data to support one being better than the other. This is a great question and it's exactly the kind of question that we get all the time and I'm going to disappoint her and tell her a big fat, it depends. So backing up, what's the difference between time restricted eating and intermittent fasting? So intermittent fasting refers to

any kind of dietary program that says I'm going to eat this many hours on, on meaning in which I'm allowed to eat and then this many hours off. So I'm not allowed to eat. So different ratios of time on versus off are popular. Anything from like eight hours of eating to 16 hours of not eating or, you know, 12 hours in which eating is permitted to 12 hours in which it's not. And those hours can happen at any time of day, almost always in a continuous block. You don't typically see like I'm going to eat, you know, breakfast from eight to nine and then love, you know, it's not like on off, on off all day. It's typically one on block for the day and then the rest off within intermittent fasting. Those hours can happen anywhere. Time restricted eating you can think of as a

special flavor of intermittent fasting, which is inspired by the circadian rhythm. So typically you see something along the lines of like eating during daytime and then not eating during nighttime. And the idea behind it is that it's following some kind of biological pattern that it's more natural evolutionarily for humans to eat during the day and not eat at night. Depending on how you implement intermittent fasting, it can look very, very similar to time restricted eating. Whoop currently doesn't separate time restricted eating from intermittent fasting. Like I said, time restricted eating is just a special variant of intermittent fasting. So in our journal, we only track intermittent fasting.

It's a great recommendation. We should totally add time restricted eating. Once we have both, we can start to do analyses on how other downstream loop metrics like recovery and sleep respond to one versus the other. So everything I'm going to talk about in terms of time restricted eating versus intermittent fasting is not original loop research, but more just the broad understanding from lots and lots of other studies. that have been done on these topics. And now the spicy question. Alee is asking, you know, is one better than the other? And the sort of unsatisfying answer of it depends is it depends on what your goals are.

And it also depends on what's feasible for your life. If you're a surgeon and you're working at night, you've got to eat when you have a chance to eat. You can't eat while you're doing surgery. And depending on the time that you're on call or not, it might be completely impractical for you to get your eating in during daylight hours because that might be where you need to sleep in order to be optimally rested to do this important work at night. And so there might be any number of social and work-related constraints that make you following a strict time-restricted eating, not just impractical. but also ill-advisable. There's a number of reasons why people follow these different kinds of diets. Sometimes it's in an attempt to lose weight.

Sometimes it's just this idea of trying to optimize your circadian rhythm. We do know that all things being equal, there are advantages to following a time-restricted eating protocols. Certainly there are advantages to not snacking through all hours of the night. But I generally dislike any really rigid diet plan or nutritional recommendation because there's a million different reasons why an exception could make a lot of sense. In general, it's not great for our sleep to be super duper hungry when we go to bed. And so while the quote unquote ideal way to get your food in is during daytime hours

and to not be eating super close to bedtime, we've done a lot of research. and shown that like a late meal is correlated with poorer recovery, but where that gets complicated is you're not always trading off like should I eat dinner at 6 p.m. or 8 p.m. Sometimes it's 9 p.m. and you haven't eaten dinner. And so it should I eat dinner now or should I not eat until breakfast? And that's a more complicated question because our sleep quality will be lower if we're really, really hungry going to bed. And so there, you know, it's not this black and white of is it a good idea to eat dinner at 9 o'clock, you know, generally that's less good than 6 o'clock, but maybe better than not eating at all. And, you know, how can you make that, you know, the least disruptive to

sleep? Well, let's think about what you're eating. You know, if you're going to eat a huge bowl of junk food, you know, something with a lot of sugar, it's going to like spike your blood sugar, this is going to be very different than having, you know, a little bit of protein, a little bit of fat, enough to make you comfortable, you know, so you're not going to bed starving and, you know, sort of satisfy that need and then move on. So, in an ideal world, there's a lot of good ideas and good science behind these different dietary protocols, but what's going to be better has a lot to do with your needs, your schedule, what's practical for you. And so, you know, I really urge people when they're looking at all this

research, and there's a lot of good research out there on intermittent fasting and time-restricted eating. And then it's going to conclude something like, and therefore this is the best protocol to really take all of that with a grain of salt and think about what's the actual takeaway and how can I fit that into my life and maybe keep some of these principles in mind versus like, you know, set a hard, hard line of like I'm never going to eat anything after, you know, sundown or something like that because that can just be, you know, in the name of doing something healthy, you could actually be acting against your own interests. And so I'm always going to be hesitant to say that one diet is better than another. And, you know, I think there's a lot of

interesting things we can learn from both of these diets, a lot of things that, you know, when we have control over our days, we can think about implementing. But I think probably both of them are bad if done really rigidly and without any kind of exception because there are real times in which exceptions make a ton of sense. Thank you so much to everybody who wrote in with your questions. It was so much fun to dig into them. If there are other questions you'd love for me or one of my colleagues to address in a future listener questions episode, please write in.

We love to hear from you until next time. Thank you to Emily for answering all the questions. and thank you, our listeners, for sending in those questions. If you enjoyed this podcast, please leave us a rating or review. Don't forget to subscribe to the Whoop Podcast. Check us out on social at Whoop at Will Ahmed. If you have a question, you want to see answered on the podcast, email us, podcast at Whoop.com.

Call us 508-443-4952. New members can use the code Will, W-I-L, get a $60 credit on W-W-A-Ccessaries when you check out. And that's a wrap. Have a great Fourth of July to all. all of our listeners in the States, rock the freedom band. Thank you for listening. We'll catch you next time on the Word podcast.

Stay healthy and stay in the green.