Getting a good night’s sleep can seem elusive in our modern lives of frenzy and stress. Yet none of us can afford to compromise it if we want to stay healthy. In this article, we’ll talk about the science of sleep, and look at ways to establish a sound sleep routine for optimal sleep and health.
Sleeplessness in society
Feeling tired all the time because you're not getting enough shuteye? You're not alone. According to the 2016 Sleep Health Survey of Australian Adults, in Australia (with similar numbers across the western world), between 33% and 45% of adults suffer from sleep that's inadequate either in duration or quality, in addition to its adverse effects during daytime. Nearly a quarter report that their work lives don't allow for sufficient sleep, and about a third admit to making errors at work due to the lack of sleep or the resulting sleepiness.
The implications of poor or inadequate sleep run deeper than daytime drowsiness. Weight gain, diabetes (due to metabolic dysregulation), heart disease, cancer, dementia, and a shortened life span have all been linked to the lack of sleep quality and quantity.
It's probably no surprise that living in urban and industrialised societies is largely to blame for our poor sleeping habits. We've lost touch with many activities and styles of living, such as hunting, fighting off predators, and taking short mid-day naps. And while we may not miss facing a lion with a spear in hand, the comfort of “civilised” life made us adapt to a number of artificial elements in our daily environment that affect our sleep. Some of them are electronic devices, artificial light, and sound pollution such as noisy neighbours and traffic.
The science of sleep
Research shows that sleep consists of two stages - the Rapid Eye Movement (REM) stage and the Non-REM (NREM) stage. The NREM stage also consists of several phases that are increasingly deeper in nature. During a healthy night of sleep, your brain goes through 5-7 cycles of these stages and phases. While eye movement is detected during all of them, you can generally think of REM as a cycle in which the person is experiencing a dream (hence the rapidity of the eye movement); and NREM is a state of dreamless sleep.
NREM and REM stages of sleep have different functions in our cognition. NREM involves storing and strengthening memories, while REM is about connecting memories with past experiences to make them stronger, expanding knowledge, enhancing problem solving and creativity, and recalibrating emotions.
And when it comes to sleep-wake times, there is some evidence that being an early bird or night owl (your 'chronotype') is influenced by your genetics. Your personal chronotype is likely derived from your ancestors who had to sleep in shifts to protect the tribe from predators during the night.
Owls, who make up about 30% of the population, take longer to feel awake in the morning, and prefer to go to sleep later in the evening. This tendency explains the high numbers of people who systematically feel sleepy at work and experienced adverse health effects as a result. Morning types - larks - make up about 40%, and the remaining 30% are a mix, with a tendency to be more like owls than larks.
Are you getting enough sleep?
You know you’re sleep deprived when you have to sleep in when you don’t set an alarm, need caffeine in the morning to function properly, have poor concentration, or feel sleepy during the day. And unfortunately, trying to make up lost sleep on your day off doesn’t work, according to a study done at the University of Colorado.
In terms of sleep duration, humans need more than seven hours of sleep each night so our bodies can rest, repair, and help maintain health. Sleep quality matters, too. As we get older, NREM sleep declines. From late to mid 40s, there are reductions of 60-70% in comparison to a teenager, and an 80-90% reduction at around 70 years old. Circadian timing also shifts with advanced age, caused by an earlier evening release and peak of melatonin, leading to earlier sleep and wake times.
Next is the issue of fragmentation - which is waking up during the night which might be due to a weaker bladder, medications, and chronic diseases, or simply sleeping more lightly and being easily woken. Sleep efficiency (time spent in bed vs time slept in bed) drops to 70-80% when in our 80s. The lower the sleep efficiency, the higher the risk of mortality, even controlling for factors such as exercise, smoking, BMI and medications.
Establishing a healthy sleep routine now will increase the likelihood of preserving sleep quality in the future, so following are ways to set up your sleep environment and routine for the best possible sleep.
Tips on improving your sleep
Improving your sleep involves making some changes in your behaviour, environment, and diet. You don’t have to change your entire lifestyle in one day. Just implement one tip at a time, and that will make a world of a difference.
Going to bed and waking up at the same time each day keeps your body clock balanced.
Symptoms of a disrupted circadian rhythm are exactly what jet lag is. A circadian rhythm is a roughly 24-hour cycle in your body, which is regulated by the suprachiasmatic nucleus in your brain. This rhythm is responsible for regulating many body functions, such as body temperature, hormonal patterns, and metabolism, and impacts all organs. This is why keeping the same sleep and wake times each day of the week is important. Unfortunately, your body doesn't know the difference between a weekday or a weekend, so sleeping in on the weekend trying to catch up for lost sleep will only keep your circadian rhythm in flux, and perpetuating that tired groggy feeling of jetlag.
Aim for around 8 hours of sleep each night.
Note that time in bed is greater than sleep time. Allow 9 hours of sleep opportunity in bed to get 8 hours of sleep. That said, each person is different, depending on how long it takes one to get to sleep, so find your sweet spot. Note that you might need more sleep if you’re feeling particularly stressed or unwell. If needed, set an alarm for an hour before bed to remind you to start winding down.
Consider that biphasic sleep may be better than monophasic sleep
Some African tribes, unspoiled by the downsides of electricity, maintain healthy amounts and cycles of sleep. One of the characteristics of sleep that is important is biphasic vs monophasic sleep cycle. As the words suggest, biphasic refers to sleep in two phases - a longer period at night and a short one as part of a siesta during the day. And monophasic sleep is an attempt or a practice to get all the sleep in one shot - something that very rarely happens. As it turns out, members of the African tribes mentioned above have a biphasic sleep pattern (seven to eight hours of sleep at night in addition to half an hour to an hour during the day).
In fact, according to a study done at Rutgers University, “The benefits of daytime napping include increased cognitive performance, feelings of invigoration, and increased late-day alertness,”.
If you do decide to take an afternoon nap, avoid napping after 3pm, and limit it to 30 or so minutes.
Avoid exercise before bed.
Exercise is important for healthy sleep. Do at least 30 minutes per day – just avoid doing any 2-3 hours before bed to avoid an exercise-induced rise in cortisol that can inhibit the release of sleep hormone melatonin, resulting in problems with getting to sleep.
Have a winding down routine.
Create a sleep hygiene routine that relaxes your body and mind for at least 30 minutes before bedtime to prepare your body for sleep. Brush your teeth, enjoy some light reading of a book or magazine, listen to gentle music or have an Epsom salt bath. Avoid TV, screens and anything too stimulating.
Only go to bed when you’re tired.
Your routine above should trigger sleepiness. Head to bed when you feel sleepy. Be mindful to not miss your window of sleep opportunity, as you might be waiting 90 minutes for the next sleep cycle to arrive.
Expose yourself to morning sunlight
If you have a disrupted circadian rhythm, or feel unrefreshed in the morning, exposing yourself to the morning sunlight for 30-60 minutes can help balance your body clock. You can do this by going outside and simply standing with your face towards the sun and closing your eyes. It's also a great time to do some relaxing breathwork or mindfulness. This is a little trickier in the darker, cooler winter months, so aim to find natural light as early as you can in the day.
Dim the lights a few hours before bed.
Better yet, get some red light bulbs for your lounge and bedroom lamps, and if you’re looking at screens in the evening, blue blocker glasses can reduce your exposure to the blue light there.
Block all light out of your bedroom.
Artificial light from screens or lights can suppress melatonin production. If needed, buy black-out blinds or wear a good sleep mask.
Your bedroom should be for sleep (and sex) only.
Limit noise and disruption. Make your bedroom as comfy as you can – invest in a good mattress and pillows.
Keep your bedroom cool.
Maintain a temperature between 19-21C.
Avoid booze at night.
Alcohol disrupts all your sleep cycles as it is a nervous system depressant, and you’ll also deprive yourself of REM sleep where memory formation occurs. It's, therefore, best to avoid alcohol for at least 4 hours before going to bed, and keep drinking to 1-2 drinks.
Relying on caffeine daily for energy points to the caffeine impairing your sleep, making you reliant on it, which is a vicious cycle. Caffeine also inhibits adenosine, the chemical in your brain that helps you fall asleep. Give it a good break and opt for getting more sleep instead.
Avoid heavy meals 2-3 hours before bed.
Finish eating your dinner several hours before sleep so your body can focus on sleep rather than digestion while you’re sleeping. The process of digestion is intensive, which takes energy away from repair processes that are active during sleep, and can also reduce sleep quality, leading you to feel tired the next day. Also, your digestive system needs time to rest and repair during the night. If your digestive system is still busy digesting your food, this important stage will be limited which can lead to digestive issues.
Support your melatonin production.
Melatonin helps you get to sleep, so if you struggle with that, eat some high tryptophan foods such as milk, dairy, turkey, meats, nuts, eggs, legumes, pumpkin and sesame seeds early in the day versus in the evening.
Tryptophan is a precursor of melatonin, and having starchy vegetables like sweet potatoes, potatoes, carrots or rice at dinner time can help your body create melatonin.
Good quality sleep will help you stay alert, keep you in good physical, mental, and emotional health, regulate your immune system and metabolism, as well as your appetite - and help keep you in good health for now and the future. So, we'd love for you to pick a behavioural, environmental, or nutritional tip from above that you think will help you improve your sleep the most, and act on it. Then, let us know how you get on by posting in the comments below!
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