Why Am I So Tired?
Do you find that some days you feel exhausted and unmotivated to attack the day like you want to? Are you lacking the energy to head to the gym, get that project done, write that blog post or study for that exam? We all have off days where we feel tired and don't want to do things, even me!
My time doing oncall and night shifts as a surgeon and then working on my side hustle businesses gave me good insight into how to stay energised and be as productive with my time as possible.
I want to explore some key methods for breaking out of that cycle of malaise and help you to recognise when you are running low on battery power and what to do to optimise your day to stay on track and get things done to achieve your goals.
Before I get started, I want to mention that although I am a qualified doctor I’m not talking about tiredness relating to medical conditions like chronic fatigue or low mood which affect millions of people globally. I'm going to focus on that general feeling of being low on energy which can be random and lead to lost productivity. If you are struggling feeling tired all the time and have other symptoms do get a medical opinion.
So let's get into it, we're going to start by understanding just what sleep is and why it's so important and then I'm going to break down my top 4 methods to stay energised and reduce the risk of being tired:
- Sleep Hygiene
- Exercise and Mindfulness
- Sunlight & Nutrition (and coffee!)
- Life Mission and Circumstances
Sleep Science: REM and Sleep Cycle
Sleep is as essential to life as food and water and you spend about one-third of your time doing it. Without sleep you can’t form or maintain the pathways in your brain that let you learn and create new memories, and it’s harder to concentrate and respond quickly. Just a few of the numerous processes occurring during sleep include memory consolidation, clearance of brain metabolites and restoration of nervous, immune, skeletal, and muscular systems.
Research from the National Sleep Foundation suggests that we need at least seven hours of sleep to function at our best. In today's hectic society that can be tough with scientists agreeing that we’re sleeping less than we were 40 years ago.
So you just need to set your alarm for 7-hours sleep right? Well it's not quite that easy. If you have ever slept a full eight hours and still woken up feeling sluggish that's probably because of the human sleep cycle. Over the course of the night, your total sleep is made up of several rounds of the sleep cycle, which is composed of four individual stages. In a typical night, a person goes through four to six sleep cycles.
Sleep is divided into two broad types: non-rapid eye movement (non-REM or NREM) sleep and rapid eye movement (REM) sleep. Non-REM sleep occurs first and after a transitional period is called slow-wave sleep or deep sleep. During this phase, body temperature and heart rate fall, and the brain uses less energy. REM sleep represents a smaller portion of total sleep time. It is the main occasion for dreams (or nightmares), and is associated with fast brain waves, eye movements, loss of muscle tone and suspension of homeostasis.
Not all sleep cycles are the same length, but on average they last about 90 minutes each occurring 4–6 times in a good night's sleep. As these are averages don't try and hack your sleep by setting an alarm in 90-minute intervals as there is some variability (more on alarms in a second). The American Academy of Sleep Medicine (AASM) divides NREM into three stages (stages 2, 3 and 4 in the hypnograph below) the last of which is also called delta sleep or slow-wave sleep.
If you get woken up in the middle of a sleep cycle, you’re going to wake up tired. As Pierce J. Howard put it in his book The Owner’s Manual for the Brain:
“A person who sleeps only four cycles (6 hours) will feel more rested than someone who has slept for 8-10 hours but who has not been allowed to complete any one cycle because of being awakened before it was completed.”
The more sleep deprived we are, the less likely we are to notice the effects. In a famous experiment from Van Dongen et al in 2003, 3 groups of volunteers slept for a maximum of 4 hours, 6 hours or 8 hours per night for 14 days. Each day participants completed a test of alertness, called the psychomotor vigilance test (PVT). This involves pressing a button as quickly as possible in response to numbers appearing on a screen. The shortest sleepers always performed the worst on the PVT test, making the most errors. Performance worsened progressively each day: the greater the ‘sleep debt’ that accumulated over time, the more mistakes were made. But when participants were asked how alert they felt, self-ratings of sleepiness only increased for 3 days - after that, perceptions of sleepiness stabilized. Participants felt as though they were adapting to short sleep, but their performance revealed otherwise.
It seems that we’re hard-wired to underestimate sleep loss, so how can we improve our sleep and wake up energised? Well now we understand a little about sleep and sleep cycles let's dive into how we can improve our quality of sleep.
As we now know hitting your sleep cycles is key to waking up feeling energised and we also know that sleep cycle varies from person-to-person. If your sleep is interrupted mid-cycle you're going to be tired. If you have a varying bed time and are being woken up by an alarm your sleep is going to be interrupted. The first step to improving your sleep is therefore all about defining your sleep window.
To figure-out your sleep window (the time you allocate for sleep each night) start keeping a sleep diary and noting down your bedtime and waking time for a few weeks. This can also be done with sleep tracking tech which we'll touch on in a bit or just keeping a note (you might also want to note down how energised you feel on waking). You will then be able to calculate your average sleep time over a few weeks. Add on 45-minutes to this number (we'll assume based on our stats from the National Sleep Foundation) that you are under-sleeping.
Now that you have a personalised sleep window let's pick your bedtime. Most people use alarms to wake up for work or school but we want you waking up naturally as your sleep cycles end without interruption (it's what humans have been doing since cave person times). Pick a time that works for you so that you wake up in time and for the first few weeks of playing with this technique it is fine to set an alarm as a safety net.
Wind Down Routine
Now that you have your schedule the focus moves to sticking with it and habit formation; more on this in other videos but for now let's just acknowledge that humans are not great when it comes to going to sleep. I'm guilty of it trying to pack in as much during waking hours as possible whether that is work, social arrangement, watching a TV show or exercising we expect to cram in as much as possible and then instantly go to sleep when our head hits the pillow. Unfortunately having a racing mind just before bed often leads to the inability to fall asleep and so having a wind down routine is crucial. I've found this to be one of the most important factors to getting a good night's rest.
Firstly prioritise your sleep and blockout in your diary or set a reminder 1-2 hours before your sleep scheduled head down time. Next fill this time with things that you find calming and relaxing to start your wind down. This might be reading a book, meditating, listening to relaxing music or anything that is passive and which you enjoy. We'll touch on this again in exercise and mindfulness shortly.
Your sleep environment is also very important as part of your wind down routine. Where you sleep should be set up to win at sleep and you should avoid working from bed.
Comfy Bed: Invest in a comfy mattress, pillows and sheets and duvet. These can be expensive but given you spend 1/3 of your life sleeping, stretched-out over time it is an excellent per day/hour investment. Many companies have popped up to focus on sleep comfort such as Casper, Nectar, Eve, Simba and lot's of others. Make your bed in the morning so it is all set for sleeping that night.
Dim Your Lights: Try to keep away from bright lights because they can hinder the production of melatonin, a hormone that the body creates to facilitate sleep. Keep your sleep environment dark with black-out blinds or use an eye mask.
Unplug From Electronics: Build in a 30-60 minute pre-bed buffer time that is device-free. Cell phones, tablets, and laptops cause mental stimulation that is hard to shut off and also generate blue light (visible light with relatively short wavelengths) that decreases melatonin production.
Test Methods of Relaxation: Instead of making falling asleep your goal, it’s often easier to focus on relaxation. Meditation, mindfulness, paced breathing, and other relaxation techniques can put you in the right mindset for bed. Apps like Calm now include Sleep Stories to help you wind down.
I'm a big fan of FitBit's sleep tracking ability on the Charge and other models which can also look at oxygenation levels while you sleep. Apple watch and other trackers have this ability too. I'll cover sleep tracking in a separate post. There are also lots of great habit trackers and gamified sleep tracking apps such as SleepWatch and SleepTown.
According to Sleep Expert Dr. Phyllis Zee of Northwestern University, the best naps are between 1 p.m. 3 p.m. and last between 20 and 40 minutes.
That afternoon timing is best for your body clock, whereas napping later in the day can affect how well you sleep that night. Taking a nap longer than 40 minutes can cause your brain to slow-wave (deeper) sleep, which'll leave you waking up in a state of confusion -- the opposite of what you were trying to solve for.
Exercise and Mindfulness
Now that we've optimised for good sleep habits and hygiene let's look at how we can support our sleep and feel more energised when awake using exercise and mindfulness.
Improving Energy With Exercise
The relationship between exercise and sleep has been extensively investigated by researchers. Studies have highlighted that exercise can improve sleep-related problems and help you to get a good night's sleep. Recent research also suggests insufficient or poor-quality sleep can lead to lower levels of physical activity the following day, identifying that sleep and exercise have a bidirectional relationship. In other words, optimizing your exercise routine can potentially help you sleep better and getting an adequate amount of sleep may promote healthier physical activity levels during the day.
Exercise itself has also been shown to improve energy levels and in a University of Georgia research study researchers reviewed more than 65 studies related to fatigue and physical activity and involving almost seven thousand participants.
Over 90% of all of the studies demonstrated the same effect: less fatigue was reported by those people who took part in and completed an active physical regimen when compared with their counterparts who did no exercise. The results were clear: more exercise equals more energy and less fatigue.
A study done at the University of Georgia in 2008 also found that young adults who did just 20 minutes of low-intensity exercise 3 times a week experienced both higher daily energy levels and much lower levels of fatigue.
Early morning exercise such as a walk or starved cardio can get your heart pumping and kickstart your day. Higher intensity weight lifting and HiiT can increase the blood supply to the brain and the release dopamine and serotonin and help reduce stress to keep you energised and on track during your day.
Improving Energy With Mindfulness
Similarly studies have shown that mindfulness can help focus and energise our brains in the morning and throughout the day. According to one study, intensive meditation can help you focus and sustain your attention -- even during the most boring of tasks. It also helps boost your mood: A 2012 study found that people who meditated "stayed on tasks longer and made fewer task switches, as well as reporting less negative feedback after task performance." And as we have seen above mindfulness and meditation can reciprocally help with your wind down routine and help you get to sleep.
Nutrition and Sunlight
All living organisms need fuel provide energy for life. In humans that fuel is what we eat and drink and the light spectrums we absorb through the skin. Getting the right food, water and sun exposure at the right intervals is critical to avoiding energy drops and feeling tired.
Food and Energy
The energy content of food is can be found by burning it and measuring how much heat energy is released and measured in kilocalories (measure of heat rise) or kilojoules (measure of energy rise). I'll go into detail on nutrition in another post but for now it is simply important to know that your body burns an amount of energy from daily activities (your Basal Metabolic Rate or BMR) and requires certain levels of nutrients. If you skip a meal, eat unhealthily or move into starvation your body compensates by trying to reduce energy expenditure making you feel tired and lethargic. Thus regular meals and not skipping meals helps for a regular supply of energy in the form of your calories (composed of carbohydrates, protein and fats). On average, women should have around 2,000 calories a day (8,400 kilojoules) and men should have around 2,500 calories a day (10,500 kilojoules).
The UK's NHS offers the following recommendations for balancing your diet for energy:
- eat at least 5 portions of a variety of fruit and vegetables every day
- base meals on potatoes, bread, rice, pasta or other starchy carbohydrates – choose wholegrain versions where possible
- have some dairy, or dairy alternatives such as soya drinks – choose lower-fat and lower-sugar options
- eat some beans, pulses, fish, eggs, meat and other protein – including 2 portions of fish every week, 1 of which should be oily
- choose unsaturated oils and spreads, and eat them in small amounts
- drink 8 glasses of fluid a day
In a busy week it can be difficult eating well and the ease of ordering junk food is always a temptation. Meal planning and meal prepping ahead of the week is your friend here as is investing in tupperware and containers to store your food. Good preparation wins everytime. Some cool options for meal prep containers include Fitpacker and Swell.
Water and Fluids
On point of water the U.S. National Academies of Sciences, Engineering, and Medicine determined that an adequate daily fluid intake is:
- 3.7 liters of fluids a day for men
- 2.7 liters of fluids a day for women
These recommendations cover fluids from water, other beverages and food. About 20% of daily fluid intake usually comes from food and the rest from drinks.
Sunlight and Vitamin D For Energy
Equally as important as regular healthy meals and water is sunlight. Sunlight exposure helps your body correctly time its production of melatonin, the hormone we mentioned earlier that helps you go to sleep and plays a part in maintaining your circadian rhythm, which ensures that you stay in sync with the day and night cycle.
Sunlight is also your body’s primary source of Vitamin D, which is not only important for keeping your bones healthy, supporting your immune system, and keeping your lungs working, but also plays a role in helping you avoid fatigue.
A study done in 2014 found a high correlation between Vitamin D deficiency and fatigue, as well as an improvement in fatigue symptoms when the patients in the study got their Vitamin D levels back to normal.
An estimated 1bn people globally suffer with a deficiency of Vitamin D and getting just 20 minutes of sun exposure each day can help you to hit your recommended daily 800iU of Vitamin D. If you are in a country like the UK where sunlight is infrequent Vitamin D supplements should be considered as should upping your oily fish intake.
Stimulants and Coffee
I drink a max of 1 cup of coffee a day (usually a latte or cappuccino around 190 kcal, sometimes a mocha nearer 300kcal). I usually drink it first thing in the morning or after lunch and don't drink coffee everyday. The problem with stimulants is that your body will build a tolerance to them requiring more each time to have a similar effect and, if taken late enough in the day (I never drink coffee after 4pm), it can mess with the quality of your sleep.
Caffeine acts as an “adenosine receptor antagonist.” Adenosine is a substance in your body that promotes sleep. Caffeine blocks the adenosine receptor to keep you from feeling sleepy. Caffeine reaches a peak level in your blood within 30 to 60 minutes and has a half-life of 3 to 5 hours. Once the caffeine has moved through your system all that built-up adenosine comes rushing in all at once, causing that post-coffee crash.
Alcohol can induce drowsiness, so some people are keen on a nightcap before bed. Unfortunately, alcohol affects the brain in ways that can lower sleep quality, and for that reason, it’s best to avoid alcohol in the lead-up to bedtime.
Life Mission and Circumstances
While we have touched on some heavy science and physiological ways to stop being tired all the time it is important to conclude by focusing on what I believe to be the most important way to feel energised every single day regardless of whether you feel tired or not. Mindset and enjoyment helped me to code and build successful businesses around my busy life as a surgeon sometimes coming back from a night-shift and coding or closing deals despite having only grabbed 3 hours of sleep.
In an interview with the Financial Times, legendary investor Warren Buffett shared what drives him to keep going so strong at his age.
"Why do I get up every day and jump out of bed and I'm excited at 88? It's because I love what I do and love the people I do it with. I've got 25 people out here. We go to baseball games together. They try and make my life good, I try and make their life good."
We spend more awake hours at work than we do away from work, which begs the question: Do you love your job and the people you work with?
Buffett has gone on record to say that the people who are most successful are "those who are doing what they love." Other iconic figures of the business world would agree wholeheartedly with that assessment.
If we pull together all of these concepts it aligns back to some of the core principles which I coach people about namely prioritising your health and fitness and also your happiness in terms of your journey and everyday routine. This is human performance optimisation in action and combined with a growth mindset will help you to achieve your goals while being more obsessed about the journey to get there and having fun along the way.