Interview with Alexandra Zatarain, Eight Sleep Cofounder: The 5 Sleep Rules Every Woman Should Know

Why do we need to take women’s sleep more seriously?

We can make time for workouts, plan healthy meals, and do all the things we associate with taking care of ourselves. But if we are consistently cutting sleep short, we are leaving out a fundamental pillar of health.

Alexandra Zatarain joins Dr. Thais Aliabadi and Mary Alice Haney to discuss the importance of sleep for women. For women, the conversation also needs to go beyond getting to bed earlier. We may suddenly find ourselves awake at 3 or 4 in the morning, throwing off the covers, pulling them back on, and wondering why the sleep that once came so easily has disappeared. Hormones, temperature, anxiety, pregnancy, menopause, and even the person beside us can all be part of the picture.

Our starting point should be curiosity, not blame. When we cannot sleep, we need to understand why. A sleeping pill, a new mattress, or a perfect bedtime routine cannot address every possible cause.

We also need to stop treating the weekend as a reliable reset button for a week of insufficient sleep. The goal is to give ourselves enough opportunity to recover regularly, rather than repeatedly borrowing from sleep and hoping to settle the account later.

How did Eight Sleep begin, and why did temperature become its focus?

We started with a very practical question: Why couldn’t our bed help us understand what happened to our body overnight?

Matteo, our cofounder, began struggling with sleep and restless legs. Around 2013 and 2014, the consumer tools available for understanding sleep were very different from what we have today. Tracking steps was becoming familiar, but getting meaningful information about a night of sleep was much harder.

The original idea was to bring technology into the bed so we could wake up with information about sleep and biometrics. Our technical cofounder, Max, began building a prototype in a San Francisco garage. We brought together engineering, entrepreneurship, marketing, and communications, but we were not sleep scientists. We knew we needed people who had spent their careers studying this.

Early scientific advisers helped redirect the question. Collecting data was interesting, but what could we actually change to help someone sleep? Their answer was temperature.

There was a personal motivation behind the company, too. Alexandra’s father experienced severe sleep disruption and difficulty regulating his temperature while undergoing chemotherapy before his death from colon cancer. That experience made the potential to improve comfort and rest feel especially meaningful.

That combination shaped our approach: understand what is happening, then build something that can respond instead of simply handing us another report.

Why can perimenopause and menopause change sleep so dramatically?

We need to think about several overlapping changes, not one isolated symptom. As Dr. Thaïs Aliabadi explains, estrogen can fluctuate unpredictably during perimenopause before remaining low after menopause. At the same time, ovulation becomes less predictable, affecting progesterone production.

Progesterone has calming effects in the brain. One of its metabolites, allopregnanolone, acts on GABA-A receptors, which are involved in that calming response. When these hormonal patterns change, we may notice changes in mood, stress, and sleep together.

Temperature regulation is another major piece. The hypothalamus helps regulate our internal temperature, and estrogen plays an important role in that system. With hormonal fluctuations and declining estrogen, the range in which we feel comfortably warm or cool can narrow.

That helps explain an experience many of us recognize: we feel freezing, reach for a blanket, and a few minutes later need the air conditioning. At night, those swings can become hot flashes, night sweats, and repeated awakenings.

But temperature is not the entire explanation. Aging can also change our sleep patterns, with lighter sleep and more awakenings. Anxiety and irritability can make it harder to fall asleep again. We also need to consider sleep apnea rather than assuming every new sleep problem is simply menopause.

Our guide to menopausal sleep disorders explores why this deserves a broader medical conversation. The important message is that a change in sleep is real and worth investigating.

How do anxiety and interrupted sleep feed into each other?

We may wake because we are hot, uncomfortable, or simply sleeping more lightly. Then our mind gets involved. We start thinking about tomorrow, how little sleep remains, and how exhausted we are going to feel.

Now the original interruption has become a second problem: anxiety about being awake. That anxiety makes returning to sleep harder, which creates even more worry about the next night.

This is why we should resist reducing women’s sleep complaints to one number. We might spend enough hours in bed and still experience repeated interruptions, racing thoughts, and a very different quality of rest from what we had before perimenopause.

We also need to take lived experience seriously. In our research discussion, we emphasized that comparing women with men of the same age can miss an important question: How has women’s sleep changed compared with their own earlier life stage? Sleeping longer than someone else does not mean we are sleeping well.

What is the connection between body temperature and our circadian rhythm?

We have an internal daily rhythm that helps coordinate when we feel alert and when we are ready for rest. Light and temperature are important signals within that rhythm.

As bedtime approaches, core body temperature generally falls. It remains lower during the night and begins rising toward morning. We often describe the overall pattern as a U-shaped curve. Core temperature is not exactly the same thing as how warm our skin feels, but the sleeping environment can influence our comfort as we move through the night.

A simple way to picture this is the natural change from evening to morning: the sun goes down and the environment cools; the sun comes up and it warms again. Our modern bedrooms do not necessarily follow that pattern. Heating, air conditioning, heavy pajamas, bedding, and another person’s preferences can all complicate it.

We are not trying to make everyone sleep at the same temperature. We are trying to support a comfortable environment as the body’s needs change. That becomes especially relevant when hormonal changes make us more sensitive to temperature shifts.

For more context on symptoms that repeatedly interrupt rest, our resource on hot flashes and night sweats explains why addressing nighttime comfort matters.

Why are pregnancy and postpartum part of the same conversation?

We experience temperature and sleep changes across several phases of women’s lives, not only menopause. Pregnancy, postpartum, and the menstrual cycle all deserve attention.

During pregnancy, many of us feel progressively warmer. Hormonal changes and changes in body size can affect nighttime comfort. After delivery, another major hormonal shift can bring further temperature fluctuations. Meanwhile, the practical business of sleeping comfortably may already involve side sleeping and what feels like a small mountain of pillows.

We launched a women’s sleep research initiative to better understand these differences. The company committed a couple of million dollars to studying sleep across perimenopause, menopause, pregnancy, postpartum, and the menstrual cycle, recruiting consenting participants from its product community.

One application was a pregnancy feature. We can enter a due date in the app, and the system adjusts the bed’s temperature approach as pregnancy progresses, continuing through eight weeks postpartum. The intention is to reduce the need to wake and manually change the environment.

There is a scientific goal and a business goal here, and we should be transparent about both. We want to contribute to understanding women’s sleep and use those findings to develop more useful products. Even without a device, the takeaway remains valuable: temperature may be contributing to our sleep disruption.

What should we know about snoring during pregnancy and beyond?

We should not automatically dismiss new snoring as a funny pregnancy side effect or a relationship annoyance. As Dr. Aliabadi points out, sleep apnea can occur during pregnancy, and it also deserves consideration during perimenopause and menopause.

We can spend the whole night apparently asleep and still wake exhausted. That is one reason a conversation about sleep should include more than bedtime and total hours.

Eight Sleep’s snoring feature uses sensors to identify body vibrations rather than recording audio through a microphone. The system reports information such as how long snoring lasts and its intensity. An optional adjustable base can elevate the head of the bed in response.

We need to distinguish that consumer feature from medical diagnosis and treatment. In the discussion, the company described pursuing FDA authorization for sleep apnea detection and mitigation, with a separate detection certification already received in Abu Dhabi at that time. Those were reported regulatory developments, not a statement that the consumer product already had U.S. authorization for those uses.

Snoring data can give us a reason to seek evaluation. It should not give us a reason to avoid it. A quieter night and properly treated sleep apnea are not interchangeable goals.

What is the difference between deep sleep and REM sleep?

We move through different sleep stages repeatedly throughout the night. A useful simplified framework is light sleep, deep sleep, and REM sleep, with cycles often described as lasting roughly 90 minutes.

Light sleep accounts for a substantial portion of the night. Deep sleep tends to be more prominent in the first half, while REM becomes more prominent in the second half. The proportions are not a nightly performance target that every person must match exactly.

We can think about the stages this way:

• Deep sleep: associated with physical restoration, immune and metabolic processes, and aspects of memory consolidation.
• REM sleep: especially important for emotional processing, learning, and memory, and commonly associated with vivid dreaming.
• Light sleep: a normal, substantial part of sleep, not wasted time between the supposedly valuable stages.

The shorthand that deep sleep restores the body and REM supports the brain is useful, but both belong in a complete night. We should not chase one at the expense of the other.

This also explains why sleep matters before a test or another demanding day. We are not simply taking time away from studying. We are giving ourselves an opportunity to consolidate what we learned.

During REM, temperature regulation is also reduced, making the environment relevant to sleep continuity. Comfortable conditions matter throughout the night, not just during the first few minutes after we get into bed.

How much sleep do we actually need?

We generally use seven to nine hours for adults as the starting range. Within that range, our needs are personal, and our experience may change across life stages.

We should pay attention to how we feel after different amounts of sleep. Do we wake relatively easily? Do we feel restored? Are we repeatedly dragging ourselves out of bed after giving ourselves only seven hours when we function better with eight or eight and a half?

When our schedule and sleep opportunity fit our needs, falling asleep and waking may become easier. But we should not turn that into another standard to fail. Pregnancy, hormonal symptoms, and underlying health conditions can make sleep difficult even when we have created plenty of time for it.

Sleep tracking can add information. Resting heart rate and heart rate variability, or HRV, can help us notice patterns in recovery. They are most useful alongside how we feel, not instead of it.

We also discussed an earlier bedtime, ideally before 11 p.m. for many people, as a way to avoid repeatedly pushing past readiness for sleep. The practical point is alignment and sufficient time, not treating one clock time as a universal prescription.

Which sleep myths should we stop relying on?

First, we should stop assuming a weekend lie-in cancels a week of short nights. Sleep debt was a major theme of our conversation. Rather than planning around delayed catch-up, we want to protect sufficient sleep consistently and respond to a short night promptly.

Second, a nightcap is not the same thing as restorative sleep. Alcohol may make us feel sleepy and help us fall asleep faster, but that sedating effect does not mean our body is recovering well. We may see resting heart rate take longer to fall and recovery metrics look worse the following morning.

Third, more difficulty sleeping as we age does not mean we no longer need sleep. If we are experiencing more awakenings, temperature swings, and racing thoughts, the answer is not automatically to accept fewer hours as our new requirement.

These myths share the same problem: they give us permission to overlook poor sleep. We want to understand what is interfering with recovery instead.

How does Eight Sleep regulate temperature without replacing the mattress?

We use a cover that fits over an existing mattress, connected to an external hub. Temperature-controlled water circulates through the cover, allowing each side of the bed to have its own settings.

That distinction matters for couples. We can share a bed without having to agree on exactly how warm it should feel. One of us may want a warmer surface at bedtime, while the other wants it cool. Our preferences can also change with pregnancy, medication, age, or hormonal transitions.

We give initial comfort feedback in the app using a scale from minus 10 to plus 10. The system then makes adjustments during the night. The company describes its newer algorithms as using previous sleep information, including estimated deep and REM sleep, to inform subsequent temperature adjustments.

The aim is to make the experience simple even when the underlying technology is complex. We should not have to wake repeatedly to manage our bedroom thermostat.

On questions about electromagnetic exposure, the company described keeping the hub and connectivity outside the sleeping surface and commissioning third-party EMF readings. That describes its design approach, rather than requiring us to accept a blanket claim that powered technology produces no emissions.

What should we do with a sleep score?

We may be tempted to open the app, look at one number, and decide whether we had a successful night. But the useful question is what we can learn from it.

Eight Sleep’s score emphasizes sleep duration and consistency. We recommend aiming for bedtimes and wake times within about a 30-minute window. If a score is consistently lower than we would like, the first things to examine are often whether we are allowing enough time and whether our schedule keeps moving around.

We also need data that reflect real households. Children climb into bed. Pets curl up beside us. The company described an updated sensor system designed to distinguish separate heartbeats and filter additional sleepers out of an individual’s report.

The broader goal is not a prettier dashboard. It is information that helps us build habits and identify patterns without adding another source of nighttime pressure.

Table of Contents

• The Five Sleep Rules We Can Put Into Practice

The Five Sleep Rules We Can Put Into Practice

Rule 1: How do we make enough time for sleep when our schedule already feels full?

We put sleep on the calendar with the same seriousness we give exercise, work, and everything else we consider nonnegotiable. Sleep cannot always be the leftover space after the day has taken everything it wants.

If we are currently getting six hours, jumping straight to eight may feel unrealistic. We can try what we call a sleep stretch: gradually expand the opportunity for rest over a week.

We might start with six and a half hours, then six hours and 45 minutes, then seven. The purpose is not to force sleep on command. It is to stop giving our body too little time and begin building a routine we can sustain.

We do not need a perfect transformation tonight. We need a practical first step toward enough rest.

Rule 2: Why does consistency matter, including on weekends?

We help our body by making the timing of sleep more predictable. That means going to bed at approximately the same time and waking at approximately the same time, including weekends as much as life allows.

Our target is roughly a 30-minute window for both. Travel, parenting, and ordinary life will sometimes interfere, but we do not need to abandon regularity because we cannot achieve it perfectly.

For those of us already dealing with hormonal changes, a steady schedule is one way to provide support while other factors feel unpredictable. We are giving our body a repeated signal about when it can expect rest.

Consistency also changes how we think about weekends. Instead of using them as a dramatic correction, we try to protect a rhythm that works throughout the week.

Rule 3: What should our bedroom feel like?

We want a bedroom that is cool, dark, and quiet. Think cave, not bright living room with a bed in it.

But cool is personal. We should not become fixated on 68°F as though it is the correct answer for every woman, every life stage, and every night. We need to find the conditions that feel comfortably cool for us.

We can also look at the full environment: pajamas, blankets, room temperature, light, and sound. If we are repeatedly overheating, changing only the thermostat may not address everything contributing to that discomfort.

The same principle applies whether we have temperature-regulating technology or not. Our environment should support rest rather than make us repeatedly wake to negotiate with it.

Rule 4: Which daytime habits deserve a second look?

We cannot separate our night from everything that happened before it. Alcohol, caffeine, heavy meals close to bedtime, and intense exercise immediately before bed can all matter.

We discussed avoiding late-afternoon caffeine, but Dr. Aliabadi adds that some women with persistent sleep problems may need a much earlier cutoff, such as 10 a.m. Our sensitivity can change, so the habit that seemed harmless years ago deserves another look.

Late workouts can also raise core body temperature just when we want our body to begin settling down. We are not arguing against exercise. We are asking whether its timing works for our sleep.

A useful review includes what we drink, when we eat, when we exercise, and how we feel afterward. Our guide to getting a good night’s sleep offers more background on creating supportive routines.

Rule 5: Why does our partner belong in the sleep conversation?

We can have excellent habits and still sleep poorly beside someone who snores loudly, prefers a very different temperature, or keeps a schedule that repeatedly disrupts ours.

We need to get on the same page about routines, the room, temperature preferences, and snoring. Otherwise, one person’s comfort may come at the expense of the other person’s rest.

This is where personalized sides of the bed can be helpful, but the principle is bigger than a product. We should be able to talk about sleep as a shared health issue rather than a nightly argument about blankets or air conditioning.

Protecting our own sleep and caring about our partner’s sleep are not competing priorities. Ideally, we make a plan that supports both.

What if we follow all five rules and still cannot sleep?

Then we need to look beyond habits. As Dr. Aliabadi emphasizes, even an excellent bed cannot treat an underlying health condition.

We should discuss persistent sleep problems with a clinician, including hormonal symptoms, thyroid concerns, anxiety, possible sleep apnea, and nighttime urinary urgency or frequency. Vaginal dryness and other menopausal urinary symptoms can also belong in that conversation. If we are waking three times a night to use the bathroom, we should not assume that nothing can be done.

For some patients, clinicians may consider micronized progesterone at night or other hormonal treatment based on symptoms and medical history. Hormone treatment is not appropriate for everyone. Dr. Aliabadi described her own breast cancer history as a reason she could not use hormone replacement, which underscores why individualized care matters.

We also discussed magnesium glycinate, magnesium L-threonate, L-theanine, and checking concerns involving vitamin B12 and vitamin D. Those are topics to review with a medical professional, not a universal supplement prescription or a substitute for finding the cause.

Our goal is not to become perfect sleepers. It is to stop normalizing exhaustion. We can protect time for rest, create a supportive environment, involve our partner, and ask for help when symptoms persist. Better sleep starts with taking our experience seriously.

This interview-style article is adapted from an educational conversation with Alexandra Zatarain, Dr. Thaïs Aliabadi, and Mary Alice Haney. It is not a substitute for individualized medical advice. Product features and regulatory developments reflect what was described during the conversation.