For listeners new to sleep science, what do scientists actually mean by good sleep? What does that consist of physiologically?

Usually it's around eight hours of sleep. Obviously, it's very personal and it could be different. We call it anywhere between seven and nine hours, so that is on average a good amount of sleep. Then, based on what we see in our data, you want at least an hour of deep sleep. I would say anywhere between 15% and 22%, 23% is usually good for me. Anywhere around 18%, I feel like a superhero. And then on the REM side, you want a bit more, somewhere in the 20% to 25% range of your time.

When we think about the solid eight hours, what makes sleep so fundamental to high-quality performance? Why are people who get five or six hours dramatically less productive than those who get the solid eight?

Let's start from the pillars of health. There are three pillars in health: one is sleep, one is nutrition, and one is fitness and workouts. At the end of the day, sleep is the most important for a simple reason. If you start sleeping two hours per night, you will start craving junk food, and there is no way you go to the gym because you feel terrible with no energy. Probably your cognitive performance will also be heavily impacted, and you will not be able to really think properly.

I don't know if you know it, but you die earlier from sleep deprivation than from starvation, just to give you a sense of how important sleep is for your body. It's more important than food, and this is physiologically proven. There are plenty of clinical studies that prove that if on a regular basis you don't take care of your sleep, you will increase the odds of a large number of health conditions. It could be Parkinson's, it could be diabetes.

But in general, even just your well-being and how you feel every morning when you wake up, I'm sure you have experienced it. After a great night of sleep, you just feel great. You're mentally sharp, you feel good, you're ready to go to the gym, you have a great day with your family, and probably you will also be able to eat healthier food.

There are different phases of sleep as well. There's REM sleep, which I'm sure everyone has heard of and is somewhat familiar with. Why are those specific stages of sleep unique and important? And from your point of view, which of them, if any, do you try to optimize?

There is what is called light sleep, deep, and REM. The most important is deep. Deep is really when your physical body is recovering, and that tends to happen more, from a percentage standpoint, in the first part of the night. REM, instead, is when your brain is recovering and readjusting all the information from the previous day and putting this information into its own library.

So in the first part of the night, there is more deep and less REM. In the second part of the night, once the physical part has recovered, you tend to have more REM than deep. So if you sleep longer, let's say you sleep nine hours instead of eight, on average you will probably get way more REM, because extending the night is when you get a higher percentage of REM. Then, obviously, in between these two is what is called light sleep. Light sleep is usually the least important, and it's the one that at Eight Sleep we want to compress.

But from a very practical standpoint, as a normal person, you care about falling asleep as fast as possible. You want as few sleep interruptions as possible. You don't want to wake up multiple times during the night. Usually people wake up because maybe they feel hot or uncomfortable, and that is where we help them with temperature. And then you want to sleep a certain number of hours with a certain amount of REM. If you check these boxes, at the end of the day, you will wake up feeling great.

Why do you think interest in sleep and the quality of sleep has been accelerating so dramatically over the past five to 10 years?

I always say sleep deprivation is the new smoking. This is the new trend. If you go back 10 or 20 years, there were the tough entrepreneurs, the macho guys: "I sleep only four hours per night because I have to work super hard." Now, if you do that, you just look like someone who doesn't take care of their own health, literally like if you were smoking.

So now I think the new leaders are leaders that are still top performers. They work really hard and deliver great results, but they still take care of themselves. If you eat junk food, if you don't go to the gym, if you don't take care of yourself and you don't sleep, you're not perceived in a very positive way as a leader nowadays. So there was this shift. It originally started with fitness and nutrition, and now is the time of sleep. This is something we have seen over the past 10 years, since we started the company 10 years ago, and it's incredible how sleep became such a hot topic that people now really discuss it while they are having dinner with their friends.

Another factor that is connected to sleep is alcohol, because now a larger percentage of the population fully understands that if you have alcohol before going to bed, it will have an impact on your sleep. That reinforces the conversation at dinner, because it connects the amount of alcohol you have to the quality of the sleep you will have.

It feels like everyone is tracking every piece of their lives, and I think that's generally a great thing, because it leads to healthier, more informed lifestyles. Maybe that's a good segue into what you and the team are announcing today. Why don't you give us the quick update on Eight Sleep?

Of course. We're launching Pod 5. It's the latest generation of our hero product, the Pod. The first Pod was launched five years ago (six), so we're at generation number five. The Pod itself is a mattress cover that you can install on top of any mattress, and it will improve your sleep by changing your body temperature. Each side of the bed has sensors. We pick up all your biometrics, and based on your biometrics, we change your body temperature. Each side has its own sensors and temperature.

Why is body temperature so important to the sleep cycle? And why is this new line, even with a blanket, that much more helpful to getting a good night's sleep?

There is plenty of clinical evidence that temperature is the most important factor impacting your sleep outside medical disorders like sleep apnea. The reason temperature is so important is that you already have what is called a circadian cycle, a circadian rhythm, so your body temperature already changes during the day. What Eight Sleep does with our technology is help your body do what it's supposed to do in changing its temperature.

As soon as you fall asleep, you want to be in a very cold environment to maximize your deep sleep. Then during the night, particularly three or four hours before waking up, you want the temperature to start rising. You also need a different temperature in deep and REM sleep. This is something that has been proven from a physiological standpoint for the past 20 years, but there was just no consumer product that was able to deliver it based on real-time biometrics. At the end of the day, we just help your body regulate its own temperature based on what physiology would recommend. We just do it for you, and that is why people like it.

A second really loved feature is particularly for people who sleep with a partner. Temperature is very personal, and it's very different based on your age, your gender, whether you work out, or whether you had alcohol or what you ate. So each person needs a different temperature every single night. When there are two people sleeping in the same bed, by splitting the temperature based on their own biometrics, we are saving the relationship.

One of the things that has been on my mind from reading some of the work and commentary you all have put out is this idea of compressing sleep: getting eight hours' worth of sleep and recovery in six. With something like Pod 5, how much closer are we, and what would it take scientifically to make that possible?

We keep making progress day after day. We already help our customers fall asleep faster. Then we help them maximize their deep sleep. They can get up to 13% more deep sleep and 17% more REM. We reduce the number of wake-ups in the middle of the night. So you just go one little step at a time, and you start gaining efficiency everywhere. The key for us will also be to help your transition from light sleep, or to reduce the amount of light sleep while maximizing deep and REM, which is really our focus.

Today we control temperature, we control elevation, and we control sound. Next, we'll want to control light. We'll want to control air temperature, air quality, and also oxygen levels. What I tell people is that you don't realize it because you're unconscious, but every night you are substantially taking the equivalent of a flight from New York to Madrid. It's an eight-hour flight, a pretty long flight. There is so much that we can optimize for you while you're unconscious to make sure that you wake up at peak energy and can deploy that energy with your loved ones or in your personal career.

That is what really excites me about Eight Sleep and the ability to control all the environmental factors to compress your sleep. First, we will give you more time back, because imagine if you could save two hours per day and still feel great. And second, anything we can do to maximize that time for your own longevity and from a health perspective will just make our company more valuable for humanity.