Why You're Always Tired: 8 Science-Based Secrets to Boost Your Energy

Have you ever felt like no matter how hard you try, you always end up feeling tired, like you're living life through a haze? You want to get things done, but you can't seem to muster up the energy to actually do them. Before bed, you scroll through an endless sea of social media, not even meaning to, but you can't figure out how to escape from this feeling of being on autopilot. I've been there, and what helped me to get out of this rut was understanding the power of sleep and some evidence-based strategies and tools that we can implement to make sure that we're getting the rest that we really need. This video will be broken down into three main parts. Firstly, I'll talk about the overarching principles of sleep optimization. Secondly, I'll talk about eight evidence-based sleep optimization tools. And finally, I'll talk about managing stress and anxiety around sleep and debunking some myths around sleep that can hold us back from getting a really good night's rest. If you're new here, my name's Izzy. I'm a Cambridge graduate and a doctor working in London. Without further ado, let's dive in. In this video, I'll be synthesizing both scientific papers and articles, books written by experts in the topic of sleep, and my own personal experiences. And I'll link all the references down below in case you're interested, and also include timestamps so you can skip ahead to the bits that interest you. First, let's dive deep into the principles of sleep and understand circadian synchronization so that we can really get a feel for why what we do during the day affects how we sleep later at night. There are two main systems that regulate our sleep-wake cycle. The first one of these is the circadian rhythm, and the second is the adenosine sleep pressure system. Firstly, the circadian rhythm. A circadian rhythm can be defined as any cycle that happens over a 24-hour period, approximately the duration of a day. One of the most important and well-known circadian rhythms is the sleep-wake cycle, but there are so many other circadian rhythms in our own bodies and also in other organisms out and about in the world. In the context of sleep, the most important things to understand about the circadian rhythm is how we can influence it. In his book, Why We Sleep, Matthew Walker talks about how our circadian rhythm will march up and down every 24 hours regardless of whether or not we've slept. This doesn't mean that it's 100% fixed, though, and the circadian rhythm can shift forwards and backwards gradually over the period of a few days. The way that it calibrates itself is with external cues, and the most important of these is a light exposure. So back before we had all these wonderful artificial lights, it would be the rising and the setting of the sun. The light signals that go into our eyes are transmitted to a part of our brain called the suprachiasmatic nucleus, which regulates the circadian rhythm. However, other than light, it also takes into account other cues such as exercise, social interaction, food, et cetera. The second sleep-regulating system is sleep pressure and adenosine. Adenosine is a chemical that, when it builds up to higher levels, it causes us to want to sleep. It makes us feel sleepy. As soon as we wake up, adenosine starts building up in the brain, just gradually, gradually building up. It keeps building up to a point where it makes us so sleepy, combined with our circadian rhythm, that we go to sleep. We can't stay awake any longer, or at least we have a very strong urge to sleep. Adenosine can almost be thought of as the opposite of caffeine, and we'll go into this in more detail later in the video when we talk about caffeine and how it affects our sleep. When it's approaching our bedtime, our suprachiasmatic nucleus, which controls our circadian rhythm, begins to produce a hormone called melatonin, which promotes sleepiness as well. So if we time our sleep so that this rise in melatonin from our circadian rhythm, along with our adenosine sleep pressure, which has been gradually increasing over the day, if we time it so that they're both high at the point that we actually want to sleep, then that will help us to fall asleep much more quickly and more deeply. This explains why it's really important to synchronize our circadian rhythm with our sleep-wake cycle, because when our circadian rhythm is trying to wake us up, then we want to actually wake up and start building up that adenosine sleep pressure so that by the time it's the evening and it's time to go to bed, we have enough sleep pressure from both adenosine and also our circadian rhythm, which is starting to tell us to go to sleep, for us to actually hit the hay and catch those Zs. If you're interested in learning more about sleep, I read the short-form summary of why we sleep by Matthew Walker, which goes into a bit more depth about all these principles of sleep without having to read the whole book. Feel free to check it out if you're interested. If you use my link down below, then you'll get a free trial and also 20% off an annual subscription. The second thing is to understand your chronotype, which essentially means that some people naturally wake up a little bit earlier, some people wake up naturally a little bit later. These people are often referred to casually as early birds or night owls, and there's also people sort of in the middle. There's a roughly even split between these three categories with slightly more early birds. Understanding your chronotype will allow you to plan actually when you should aim to go to sleep and aim to wake up because you'll find it much easier when you're in sync with your own circadian rhythm. The third thing is to allow yourself an adequately long sleep opportunity window. We all need slightly different durations of sleep. So maybe someone needs only seven hours and someone else will need nine hours. On average, around eight hours often works for people. However, see how you feel and see what your body is needing and asking for, and try going for a period of time without setting an alarm if you can. I know some of us have jobs that we need to go to or like school commitments, but if you have a little bit of time, maybe on a holiday, try to just really rest and get as much sleep as you need and see how many hours of sleep your body actually wants. So bearing all of these principles in mind, there are a few things that we can do in terms of one-time changes in terms of our environment and also daily routine strategies that can help us to sleep better. It's so important to build a comfortable sleep environment where you can relax and maintain a deep level of sleep. This generally means a quiet, dark, and cool room. There may be some one-time modifications that can really help with this. First thing that you really need is a set of blackout curtains. Let me tell you, these are a game changer. If you can't get blackout curtains for whatever reason, then an eye mask to make sure that no light gets into your eyes when you're actually trying to sleep. Second thing is to turn off any source of light from inside your room. So for example, sometimes some chargers, they'll have like a little light on it while they're charging at night. I sometimes use washi tape or just like a bit of Blu-Tack to just cover up any little charging lights that are going on in the room. The third thing is having comfortable and breathable bedding and pajamas. The fourth thing is to try to keep your room generally cool. In The Sleep Prescription, which is a book by Dr. Arek Prather, he talks about how around 18.3 degrees Celsius is the sweet spot for most people, although a good range is from 15.5 up to 19.4 degrees. And the fifth thing is to keep a quiet room. Try soundproofing your room or getting earplugs, or some people even find listening to some white noise or green noise can help, or maybe the sound of rain. For example, LeBron James says that he listens to the sound of falling rain to help him sleep throughout the night. So now I'll walk you through a normal day from morning until evening in terms of a sleep optimization routine. The main thing to do in the morning, first thing when you wake up, is to give your circadian rhythm a strong signal that the day has started and it's time to wake up. This brings us to our first tool, which is early morning light exposure. Dr. Andrew Huberman talks about this in his sleep kit where he recommends that you go outside first thing in the morning for some early morning sunlight. If it's really bright and sunny, then five to 10 minutes is enough. If it's overcast and cloudy, then between 15 to 20 minutes is recommended. Tool number two is exercise in the earlier parts of the day. In her book, The Science of Sleep, Heather Darwell-Smith talks about how exercise increases our sleep pressure. So it helps to augment the adenosine sleep pressure system. This can help us to fall asleep more quickly at night. But the key thing here is that she mentions how the timing of exercise is absolutely key. She recommends that the best times to do exercise are either in the morning where you benefit from coinciding your exercise with your natural peak in cortisol, because cortisol naturally peaks in our bodies in the morning. This can help to assist with recovery from your exercise. Alternatively, in the afternoon until maybe the early evening, like 7 p.m. Workouts later in the evening or at night can interfere negatively with sleep. Exercise causes a release of adrenaline and cortisol, increases your body temperature, and these things can all delay the release of melatonin and ultimately delay the onset of sleep. If you do have to exercise late at night, then it may be worth taking a lukewarm shower afterwards to cool down a little bit. Tool number three is using caffeine strategically. The way that caffeine makes you feel more awake is that it competes with adenosine for the adenosine receptors in the brain. When adenosine binds to the adenosine receptors, then it sends a signal to your brain to feel sleepy. And what caffeine does is it essentially blocks these receptors and prevents adenosine from sending that signal to your brain so that you end up feeling more alert. Essentially, caffeine is blocking adenosine from telling your body how much sleep pressure there is. Another thing that's really important to bear in mind is the half-life of caffeine. The half-life of a drug is the time that it takes for the blood concentration of that drug to halve. The half-life of caffeine is variable depending on the person and the context, but on average, the half-life is around five hours. That means that from when you drink a cup of coffee five hours after it's been absorbed into your system, the blood concentration of caffeine will have halved. So it's nowhere near gone. It's just sort of gradually exponentially decaying down from its initial concentration with this half-life of around five hours. Since caffeine basically blocks one of the two main mechanisms of how we feel sleepy, we ideally want caffeine to be out of our system by the time we want to go to bed, right? So this begs the question of when we should actually stop drinking caffeine. And because it's different for everyone and everyone has a different rate of processing caffeine and metabolizing it, this might take a little bit of trial and error to figure out, but a good rule of thumb is to stop drinking caffeine around 10 hours before your bedtime. For me personally, I don't drink any caffeine after 12 noon. That's when my cutoff is. Number four is the timing of meals. Essentially, you want to allow your body enough time to start digesting your meal and your dinner before you go to bed. This means ideally you should finish all your dinner and your evening meal between two to four hours before your bedtime. This will allow that two-hour buffer to rest and digest a little bit before you go to sleep. Tip number five is to limit your light exposure in the evening. This means putting away your devices and dimming the lights when it comes towards your bedtime. The CDC recommends dimming lights around two hours before your bedtime, as this is when the circadian clock is most sensitive to bright light. One thing to note is that the type of light matters. So blue light much more strongly stimulates the suprachiasmatic nucleus to give it that signal to the circadian rhythm that, oh, it's still daytime. This is why things like blue light blocking glasses or putting on night shift onto phones or laptops is so popular these days because it helps to minimize how much blue light is emitted, which affects our sleep more significantly. So if you really have to use your phone or your laptop late at night, then try using it in night mode or night shift mode, if possible, where it shifts it towards the red end of the spectrum and eliminates those blue wavelengths. Tip six is to be conscious of your alcohol intake. Chess grandmaster Fabiano Caruana reportedly doesn't drink alcohol at all purely because it affects the restorative deep sleep, which is essential for learning and memory. Since we're not all chess grandmasters, we don't all have to necessarily go to that extreme. However, it is true that drinking alcohol does significantly negatively affect your sleep. A study done in 2018 found that the impact of alcohol on sleep quality was proportional to how much you drank. Low intake would reduce sleep quality by about 9%, moderate would reduce it by about 24%, and a high intake would reduce sleep quality by nearly 40%, that's huge. So just be aware that while any alcohol does have an impact on sleep, the more that you drink, the more this effect will be, which kind of makes sense. Sort of what we would expect, right? Tip number seven is to create a relaxing bedtime routine that you look forward to. It's really difficult for your brain to go from working at 100 miles an hour all the way down to sleeping. So you need to give your body and mind some time to gradually wind down. Allocate time for this actively. I personally block it out of my calendars, my bedtime and wind down routine, and allow yourself enough time to have a really nice relaxing routine. So I usually allocate one hour. For me, my evening routine typically looks like, number one, I light some candles instead of using traditional electric lights. Two, I open my windows and air out my room to help cool it down and bring down the temperature in my room. Three, I have a warm shower or bath and I get into my pajamas. Having a warm shower actually helps your body to cool down more quickly, which seems a bit paradoxical, but essentially it allows the smaller blood vessels in the surface of the skin to dilate and drop your core body temperature. Number four is I brush my teeth, do my skincare, take care of myself, refill my bedside water bottle with filtered water. Then I do 10 minutes of gentle yoga or stretching, and then maybe a five minute meditation. Doing a meditation right before bed where you focus on mindfulness of breathing can be really helpful to help you wind down. In Zen Buddhism, some teachers have recommended that a meditation before bed where you focus on being mindful of the breath and following the cycle of the breath can help to calm the mind and prepare you for sleep. After that, I journal to get out any last thoughts of the day, just to get anything from inside my head out onto the paper so it's not gonna buzz around and keep me up at night. Finally, I hop into bed and get out my Kindle and read it on dark mode with the light settings on the lowest light and the warmest color. So essentially trying to make it look as red as possible. I read for around 10 to 20 minutes, and then when I feel sleepy, I turn it off and I go to sleep. The final tool is keeping a sleep journal or tracking your sleep. Michael Phelps, who has won 23 Olympic gold medals in swimming, places a very, very heavy emphasis on sleep. Phelps was quoted as saying, I really can't say it enough. I don't think people really pay enough attention to how important sleep is. And so he tracks his sleep meticulously, including his REM sleep, different stages of sleep, everything about his sleep. He's got all the data on it. Even just simply tracking the time that you went to bed and the time that you woke up. So tracking your sleep opportunity window can be really helpful just to see whether you're giving yourself enough of a window to have a chance at getting enough rest. If a 23 time Olympic gold medalist is doing it, there might be some stock in it. The final thing I wanted to touch on is if feelings of anxiety are getting in the way of you getting a good night's rest. Insomnia is really common these days and people are working at a higher level of stress than ever before. We're always switched on and always connected to the internet and social media. This makes it really hard for our mind to truly unwind and disconnect. If this is something that you're experiencing, incorporating some more relaxation techniques that help you to really disconnect, so such as yoga, meditation, or speaking to a therapist may be really beneficial. In her book called Hello Sleep, Dr. Jade Wu talks about how sometimes when we are struggling to fall asleep, we can have negative thoughts come up, which can actually make our insomnia worse. For example, your thoughts may go from, oh, I can't really fall asleep to I won't be able to function tomorrow, which triggers anxiety and all these negative automatic thoughts and feelings. Dr. Wu suggests that if you do have any of these automatic negative thoughts coming up, that you maybe question them gently. And one of my favorite questions that she asks the reader is what's a more fair, balanced, and accurate way to think about this situation? This isn't asking us to just be falsely positive about things. It's inviting us to be more gentle with ourselves and approach things with a more fair and balanced view and take into account all the things that we are doing to try to fall asleep. One thing that can help if you're struggling to fall asleep is to get up out of bed for maybe half an hour or so. Maybe open a window, look outside, get some fresh air, or go downstairs and make yourself a cup of chamomile tea. And sometimes once you've had that mental break away from the anxiety and the stress, then when you come back, you're in a much better place to often fall asleep. If you enjoyed this video, I think you might like this one over here where I talk more about goal-setting science and how we can change our lives by changing the way that we set our goals. Thank you so much if you've made it this far. Leave a comment down below and share which tip you're going to try out. And if you have any other sleep tips that you'd like to recommend, feel free to follow me over on Instagram at izzysealy if you want to see what I'm doing outside of YouTube. As always, thank you so much for watching. Take care of yourself, and I will see you in the next video. Bye.