The Tuur® Sleep Podcast
In bed with experts about sleep in real life
Sleep affects everything. How you feel, how you perform, and how you recover. In the Tuur® Podcast, we talk with experts who know sleep from the inside out.
People who work every day with the human body, the brain, and our nightly rest.
In In bed with… we take the time to look deeper than tips and trends.
We speak openly about what truly influences sleep quality: from mental calm and habits to physical support and recovery.
No quick fixes, but insights that help you better understand what your sleep really needs.
Each episode offers well-founded knowledge, relatable situations, and practical insights; to help you sleep more consciously, night after night.
The podcast is currently available only in Dutch. You can read the full transcript below.
One question we ask almost every day: how did you sleep? There is an incredible amount to say about sleep, but fortunately I don’t have to do that alone today. I’m joined by Jenneke Elberts, a certified sleep coach who founded the company Slaapbalans together with her husband. A sleep coach, what exactly is that? She will tell us all about the impact of worrying, nutrition, exercise and many other factors on our sleep quality. Together, we’ll get to the real foundation of good sleep.
Today, we’re talking about sleep. And sleep is something every person deals with every single day. There is so much to say about it. Luckily, I don’t have to do this alone. Today I’m sitting here with Jenneke Elberts. You are truly passionate about sleep, and together with your husband Bas you founded a company. Can you tell me a bit more about that? The company is called Slaapbalans, which already gives a hint of what it’s about.
Slaapbalans actually grew out of our own experience with insomnia. From that experience, we decided to start Slaapbalans. We help many people, mainly adults, to sleep better and more deeply. We all know the impact poor sleep has on how you function during the day. That’s why we support people through one-on-one coaching programmes and a sleep course, with the aim of improving their overall quality of life. For us, it’s not about perfect nights, but about sustainable change.
So what can I expect from working with a sleep coach? That sounds like a full process.
We indeed offer one-on-one sleep coaching. That means we work through several sessions to get to the core of the problem: what the underlying cause is and why someone is sleeping poorly. From there, we look at what can be improved and where the focus should lie. That might be stress management, sleep habits, learning healthy sleep routines, or reducing excessive worrying. All of these aspects can play a role, and we address them together. The process can be very diverse.
We all experience good nights and bad nights. When does sleep become a real problem?
Good nights and bad nights are part of life, and sleeping poorly once in a while doesn’t immediately mean there’s a serious issue. It can be unpleasant to have one or a few bad nights, of course. But it becomes problematic when it happens around three times a week and continues for more than three months. At that point, we speak of chronic insomnia. You also notice it during the day, because the complaints become so significant that they start to negatively affect your daily life.
What are the main symptoms you notice during the day with chronic insomnia?
Most notably, concentration decreases. You have less focus, your memory may decline, and there is persistent fatigue. You also tend to become more irritable, your mood suffers, you often have a shorter fuse, and you’re less alert. Those are usually the most common complaints, and many people recognise them immediately.
Based on your experience, what are the main causes of chronic sleep problems in people who sleep very poorly three or more nights a week?
The causes of chronic insomnia or sleep problems are rarely straightforward. It’s usually a combination of several factors. These can include lifestyle habits or stress-related issues. We often look at three main factors. First, there is a predisposition to sleep problems, such as a genetic tendency or certain personality traits. This is often followed by a period of increased stress, for example due to illness, a divorce, or other major life events. The third factor consists of what we call maintaining factors. These are behaviours and habits people develop in an attempt to sleep better, but which actually keep the problem going. For instance, taking more naps during the day to compensate, waking up more frequently at night, or worrying more about sleep. Over time, it’s the way you view sleep and deal with it, the habits you’ve developed, that continue to interfere with good sleep. The stressful period may have passed, but the habits that remain still prevent restful sleep.
Let’s talk about predisposition. We often hear that some people naturally sleep better than others. Is that related to genetics?
It can be genetic, but it can also be linked to personality traits. Some people are naturally perfectionists, or more prone to worrying. Those characteristics can make someone more sensitive to developing sleep problems.
Does upbringing also play a role in sleep? For example, growing up in a perfectionist household?
That’s certainly possible. It can influence how you’ve learned to think about sleep.
This seems to go beyond your field at some point, as psychology clearly plays a role here. Where does your work as a sleep coach end, and where does a psychologist take over?
We can’t do everything, and we can’t help everyone. If there is more severe psychological distress, that’s something that should be addressed together with a psychologist or a general practitioner. We are very clear about the limits of what we can guide as sleep coaches, and we respect those boundaries.
If someone starts a coaching programme with a sleep coach, what are the chances of success? You’re not aiming for perfection, of course, but for a positive shift. Is success common, or do people often need to be referred further?
As you said, we don’t aim for perfect nights. Many people feel they have to sleep perfectly, but the real goal is to develop strong, sustainable habits. That way, when you do have a less restful night—which happens to everyone—you know what to do to get back on track and sleep well again.
You say it yourself: many people worry, but they worry specifically about the fact that they’ve slept badly. It becomes a kind of vicious circle of “I’m lying here and I can’t sleep.”
That’s absolutely true. It’s often worrying about the worrying itself. You’re lying in bed thinking, “I have to sleep now, otherwise I’ll be exhausted tomorrow” or “I won’t get through the day.” And then you start worrying about what if it happens again the next night. What worrying does to your sleep is that your brain stays in problem-solving mode. Your brain remains alert, constantly thinking: “I need to fix this.” And when your brain stays alert, sleep won’t come. Because for sleep you actually need just one thing: relaxation. Calm. Worrying and the feeling of “having to” create pressure. Everything you feel you must do creates pressure. “I have to sleep, otherwise this will happen.”
So how do you switch off that worrying? Are there techniques for that?
Yes, absolutely. You can work on learning to let go of worrying. We have around 60,000 thoughts a day, and thoughts come and go. You can’t simply switch them off. That’s not possible. But you can learn to deal with them better. What we advise is that if you tend to ruminate and worry a lot, you create a designated “worry moment.” Take a notebook and write down your thoughts: what you did today, what went well, what still needs to be done. It can be anything. What you’re doing is getting everything out of your head and onto paper, so you don’t have to take it with you to bed. You can let it go. It’s basically a kind of worry journal. And do it the old-fashioned way, with a notebook and pen, not on your phone. Give yourself half an hour a day in which you’re allowed to worry and write down everything that’s on your mind. Then you can let it go.
Let’s also talk about things like performance anxiety and other mental factors such as perfectionism. Can those intensify sleep problems?
Absolutely. With perfectionism, it’s very similar: you really want to do things well, to be satisfied, and you set the bar very high for yourself. That brings back that sense of “having to.” People who are perfectionists often feel: “I have to do this right, otherwise something bad will happen.” “Having to” creates pressure, and that pressure works against sleep. Sleep has to come naturally. You can’t force it. Sleep only comes when the conditions of calm and relaxation are in place.
Let’s talk about measuring sleep. These days there are so many trackers: smartphones, watches, wearables, all of that. What’s your experience with them? Do you see them as useful tools, or not really?
You’re right, sleep trackers are available everywhere now, in all shapes and sizes. People often use them to see things like: “How much deep sleep did I get?” or “How long did I sleep?” But sleep trackers are designed to measure movement. What no sleep tracker can actually do is measure your deep sleep phase accurately, because that requires electrodes that measure brain waves. Trackers simply can’t do that. What we often see in practice is that people feel they’ve slept quite well. They wake up thinking: “That was a decent night. I feel reasonably fit.” Then they look at their sleep tracker and see something like: “Oh no, I hardly had any deep sleep,” or “I didn’t sleep well at all.” And then their perception changes. Instead of trusting how they feel, the tracker tells them: “No, you didn’t sleep well.” There’s even a term for this: orthosomnia. It means developing anxiety around sleep technology, becoming so focused on what the tracker says instead of tuning in to how you actually feel. As sleep coaches, we say: use it as a tool, as insight, but not as your final judgement. Listen to your body. Your body is very good at telling you whether you’re rested. That’s a much better indicator than a sleep tracker. So they’re fine to use, but don’t base your entire judgement on them.
I also hear that these sleep trackers often use algorithms to estimate when you might be in deep sleep, but that there isn’t much scientific accuracy behind that.
No, absolutely not. They track movement, and that’s very sensitive. All kinds of things can happen in bed, or the tracker may register a different movement. But true deep sleep is about brain waves, and you simply can’t measure that this way. No sleep tracker can.
You mentioned listening to your own body. But what if someone has felt tired their entire life and has come to see that as normal because they’ve had poor habits for a long time? Do you encounter that?
Yes, definitely. Many people think, “This is just how it is. I’m always tired. I’ve always slept like this.” And that’s such a shame, because in many cases there is still so much room for improvement. People can sleep better and feel much fitter and more rested.
What are the signs, then? They might be subtle. What are indicators that you might not be sleeping optimally?
If you’re really not sleeping optimally, you may notice that you feel quite tired during the day, that you experience more energy dips, and that you think: “I just don’t feel fit enough, not rested enough.” Those are clear signs that your sleep quality could be improved.
I go to bed at night and, so to speak, I’m knocked out for eight hours. Does that mean I’ve had eight hours of quality sleep?
No, not necessarily. The idea that everyone needs eight hours of sleep is a myth. Many people think, “I have to sleep eight hours, because then I’ve had enough sleep.” But that varies enormously from person to person. We prefer not to focus on sleep duration anymore, but on sleep quality. How much deep, restorative sleep did you get? A good indicator is how you wake up and whether you were awake many times during the night. Waking up at night is completely normal; what matters is how easily and calmly you fall back asleep.
Many people wake up during the night and may see that as a problem. But is waking up at night actually an issue?
No, not at all. We’ve come to see it as a problem, but in reality everyone wakes up during the night from time to time. That’s perfectly normal. Sometimes you remember it, sometimes you don’t. We all go through different sleep stages in cycles of about 90 minutes, and at the end of each cycle you’re in a lighter sleep stage, during which it’s common to wake up briefly.
So waking up is normal, and that means it’s okay. The question is whether you can then fall back asleep calmly, or lie awake calmly for a bit.
Exactly. It’s fine to lie awake calmly for a while without actively trying to sleep. That’s absolutely okay.
But it’s probably not a good idea to grab your smartphone at that moment.
No, preferably not. What often happens is that people wake up and think, “I’ll just quickly check my phone.” But what your smartphone does is immediately switch your brain into alert mode. It activates you, and that’s exactly what you don’t need. If you really can’t fall back asleep and your thoughts start racing again and you think, “This isn’t working,” that’s okay. But then it’s better to get out of bed and do a calm, quiet activity. When you start to feel sleepy again, you can go back to bed.
But people often say: everyone needs eight hours. That’s the basis, the average.
That idea is actually quite outdated. For a long time, we focused heavily on sleep duration, and somewhere along the way eight hours became the norm. But we can let that go. What really matters is the quality of your sleep: deep, restorative sleep. For one person, that may be achieved in six hours; another may need eight. It’s very individual.
And when we talk about quality sleep, are we talking about REM sleep?
We mainly look at what we call core sleep. That’s roughly the first four to five hours of your night. During that time, you get deep sleep and a large portion of REM sleep. REM sleep is the dreaming phase, where you process emotions and your brain resets. That first part of the night is crucial. Some people complete their core sleep in about six hours, others need closer to eight. It really differs from person to person.
You mentioned dreaming, which I find interesting. Some people remember their dreams very vividly, while others hardly ever seem to dream. Do we know why that is?
Yes, and it’s actually quite interesting: everyone dreams. The difference is that some people remember their dreams and others don’t. That often depends on the sleep stage you wake up from. If you wake up during a lighter sleep stage, you’re more likely to remember your dream. You may recall it clearly in the first five to ten minutes after waking, but then it usually fades quite quickly.
Lifestyle also plays a big role. What you do during the day has a major impact on your sleep. One of the most important factors is caffeine. We all enjoy a cup of coffee, and some people drink seven or eight cups a day. How does coffee really affect sleep?
Caffeine is indeed a major sleep disruptor. You can absolutely enjoy a cup of coffee, and coffee does have its benefits. It’s mainly about timing. Coffee in the morning or early afternoon is usually fine. But drinking it later in the afternoon or in the evening is less ideal. Your body needs about six hours to process caffeine. The later in the day you drink coffee, the more it can interfere with your night’s sleep, because your body is still processing it. Of course, this is also personal: some people metabolize caffeine faster than others. So it’s about discovering what works for you. Some people realize they should stick to one cup in the morning and stop there, because they notice it otherwise affects their sleep at night.
It’s also a bit of a social habit. When people go out for dinner, they often like to finish the meal with a cup of coffee. Can you then drink decaffeinated coffee without worries and still sleep well?
Yes, sometimes I do wonder whether there isn’t still a small amount of caffeine in it. But look, if you really enjoy that cup of coffee and it doesn’t have much effect on your sleep, then go ahead and have it. But if you notice that it does affect your sleep, you might want to try a nice cup of tea instead. That’s also an option.
You can’t avoid it: there are so many trendy energy drinks on the market, and I get the impression they’re only getting bigger and bigger. You see Monster-style cans of up to 600 ml. It almost seems as if people are trying to keep themselves going with those drinks. Do you notice that as well?
Yes, you see that when people drink them, they’re kind of bouncing around all day. Basically, they’re drinking everything they can to maintain that energy. But your energy actually comes from your night’s sleep. If you recharge properly and recover well, both physically and mentally, you wake up ready to take on the day. So in that sense, we really need to go back to basics.
Does that create a kind of dependency on those energy drinks? Do you become reliant on them?
I do think that once you get used to drinking energy drinks, it becomes harder to stop. It can feel comfortable to keep drinking them continuously, and in that way you end up maintaining that habit yourself.
Let’s talk about food. There’s so much discussion about nutrition, healthy eating, fast food. In general, can you tell us which foods—besides caffeine—have a strong positive or negative impact on sleep?
When we look at our meals, a varied diet naturally contributes positively to your night’s rest. That means carbohydrates, proteins, vitamins, vegetables. But heavy meals right before bedtime are often discouraged, because your digestion then has to work very hard, which can keep you awake. So what we usually advise is not to eat too heavily late at night. And if you still really feel like having a snack before bed—which many people do, like popcorn or chips—that’s fine occasionally. Just be mindful: if you want a snack, try something light and protein-rich, such as a bowl of yogurt or some nuts. These contain tryptophan, which contributes to the production of serotonin and melatonin—both important for good sleep. I should add that the scientific evidence here is still somewhat limited. You often hear people talk about “melatonin-rich foods,” such as cherries, bananas or nuts, but you would need to eat very large amounts to actually see a noticeable effect on your sleep.
I recently read a study that mentioned eating two kiwis before going to bed.
Well, you can leave that aside. Kiwi is of course a healthy fruit, so you can eat it without any problem. But don’t expect that eating two kiwis will suddenly make you sleep wonderfully well.
Here in the Low Countries, we tend to eat quite early compared to, for example, Spain. I often hear that this is healthier and better for sleep.
Yes. It’s a bit of the “six-o’clock rule,” eating around that time, which has become common here and works well for many people. In other countries, meals are much later, and people there have adapted their lifestyle accordingly. They often have a siesta in the afternoon, their sleep rhythm is different, they go to bed later and may wake up later as well, sometimes taking a power nap during the day.
Besides caffeine, there’s of course another major culprit: alcohol. Can you explain the effect of alcohol on sleep?
Yes, definitely. Many people think that having a nightcap—drinking alcohol before bed—will help them sleep well through the night. That’s not entirely true. Alcohol may help you fall asleep faster, but it reduces the amount of deep sleep and also REM sleep. As a result, you wake up more often during the night and your overall sleep quality is much poorer. Even if you’ve slept for several hours, you’ll often wake up feeling more tired. So alcohol is actually a significant disruptor of sleep.
And then, for example, I drink a few beers and have to go to the toilet all night long. You keep needing to use the bathroom, which keeps interrupting your sleep. I sometimes hear people say: “I stop drinking a while before going to bed, so I don’t have to go to the toilet at night.” Is that a smart tactic?
Yes, it does make sense to be mindful of not drinking too much right before going to sleep, because that will definitely have an effect. You’ll almost certainly need to get up several times during the night to use the bathroom. Just make sure you stay well hydrated during the day. Drink enough throughout the day, but ease off in the last period before bedtime so you don’t have to get up to urinate so often during the night.
What is the impact of drinking enough throughout the day on your sleep quality?
It helps improve it. You prevent dehydration, and it also helps regulate your body temperature. A stable, appropriate body temperature is important for sleeping well.
You mention temperature. Does that mean there is an ideal temperature for the bedroom?
Yes. Generally speaking, a temperature between 16°C and 18°C is considered ideal for sleeping. A dark, cool bedroom is really essential for a good night’s sleep. So basically, the darker your room, the better. And a temperature between 16°C and 18°C.
I can imagine that some people might feel uncomfortable at those temperatures. Can you then, for example, wear socks or pajamas?
Absolutely. Just wear a nice, warm pajama. Socks are also very good, because they help regulate skin temperature. They make you feel more comfortable and warmer, while your core body temperature can still drop slightly. And that drop in core temperature is exactly what helps you sleep well. So definitely wear cozy socks and comfortable pajamas.
Besides eating healthily and varied, avoiding alcohol and limiting caffeine, there are also many supplements and sleep drinks on the market that claim to improve your sleep. Can you explain which supplements might help and what the facts and myths are around supplements and sleep?
Yes, certainly. If you look at sleep drinks, they often still contain some alcohol, which again leads to poorer sleep. When it comes to supplements, many people immediately think of melatonin. In the Netherlands, melatonin is freely available at drugstores, but the issue is that melatonin is often seen as a sleeping pill. And it isn’t. Melatonin is a hormone your body naturally produces. We mainly use it when there is a disrupted rhythm—such as with shift work or jet lag. Research shows it can be effective in those cases. But taking melatonin to fall asleep faster or to sleep through the night generally has very little effect. You also need the right dosage and the right timing. That’s why we mainly recommend melatonin for rhythm disturbances. Otherwise, it’s better to return to the basics: your behavior and habits. With valerian and similar products, the scientific evidence is also limited. If you use them as a supplement and they help you relax or feel better, that’s fine. But you should always address the basics first, instead of immediately reaching for supplements.
And a step beyond supplements—or more drastic than supplements—is of course: “I’ll just take a sleeping pill, because it works so well.”
Yes, “it works so well.” Sleeping medication is still prescribed quite often by general practitioners, and that’s unfortunate. Sleeping pills have many side effects and are addictive. You often need higher doses to achieve the same effect, and they only act as a temporary fix—they don’t address the underlying cause. Always try to look at what is actually causing your poor sleep and how you can tackle that, instead of immediately turning to sleeping medication.
Let’s continue. Besides nutrition, sport and physical activity are also very important to reduce stress and perhaps worry less. How does exercise influence sleep, and how can sleep influence exercise if, for example, you want to perform at a higher level?
Sleep and physical activity are closely interconnected. You recover better when you sleep well, and when you move more during the day, you tend to sleep better at night. They really go hand in hand. The key is to move during the day in a way that works for you. One person prefers strength training at the gym, another prefers walking, swimming or cycling. It doesn’t matter, as long as you stay active. That’s a very important factor for a good night’s sleep. And when we look at elite athletes—people who train at a high level—they generally need more sleep. Coming back to sleep duration: top athletes often need around nine hours of sleep to recover properly, because of the intense physical demands they place on their bodies.
What I find quite funny is that you say elite athletes need a lot of sleep, but then when we look at the Olympic Games, they sleep on beds made of cardboard. And that’s actually not very conducive to a good night’s sleep.
Indeed. No, not at all. And often in elite sports, athletes can actually be more sensitive to sleep problems. That doesn’t so much have to do with sleep itself, but rather with performance pressure. So it’s more psychological: because they have to perform under such high pressure, it’s especially important for them to pay close attention to their sleep habits and sleep hygiene. And those cardboard beds are definitely not optimal.
I’ve learned so much today. I found it incredibly interesting. But for people who don’t want to watch or listen to the entire podcast, or for those who really want a very concrete action plan—you often talk about going back to basics and restoring healthy habits. If there were one step-by-step approach, one foundation to get a good night’s sleep going again—we’re not looking for perfection, just to set something positive in motion—what would be the basic steps someone should take?
Yes, if you go back to the basics, you start with a good daily structure. Build up enough sleep pressure during the day and keep moving. When you get up in the morning, make sure you get morning light right away. That immediately resets your biological clock and helps ensure sufficient melatonin production—the sleep hormone—in the evening. And simply keep maintaining good sleep habits. It really comes down to your behavior and routines. If you stick to that foundation and make sustainable changes, you’ll always have a solid basis for a good night’s sleep.
Besides sleep trackers, there is also other technology. I see a lot of people using UV glasses, I think, or even UV lamps, especially in winter, to stimulate daylight. Is that something that works and that you would recommend?
Yes, definitely. Daylight lamps have proven to be very effective, especially in winter, because people tend to stay indoors more and get less natural daylight. A daylight lamp has been shown to be effective in increasing exposure to daylight, so it’s certainly something I would recommend.
I’ve learned an enormous amount today. Thank you very much. If people want to find you online, where can they do that?
At slaapbalans.nl.
And people can start a coaching program with you and your husband and begin sleeping better again.
And we’re happy to be there for them. Absolutely.
Thank you for the interview.
You’re very welcome. I really enjoyed doing it.