Conventional wisdom dictates that the human body needs around 8 hours of sleep per night to ensure we feel well rested and refreshed upon waking. Despite this, many successful public figures claim to sleep just half this time and flourish.
While you’re unlikely to feel rested and energized after 4 hours of sleep, sometimes you’ll be forced into a truncated period of slumber. This could be due to a late night of work or play, insomnia, or being kept awake by roommates, a pet, a new baby, or a partner.
If you only manage to sleep 4 hours, wake up at your usual time to avoid restarting and interrupting a new sleep cycle. Take a cold shower and exercise to wake up, enjoy a sensible amount of caffeine to kickstart your day, and plan a realistic schedule for the hours ahead.
While you can get by on 4 hours of sleep occasionally, it’s not an advisable lifestyle. You should undergo a minimum of four full sleep cycles per night, and 4 hours of rest allows for just two. It’ll be tough to remain productive in such circumstances.
Can You Survive on 4 Hours of Sleep?
We can survive with 4 hours of sleep, but surviving isn’t thriving.
It’s recommended that we get a minimum of 8 hours of sleep per day for good reason. Sufficient rest enables the body to complete enough sleep cycles to function at capacity in the morning.
A sleep cycle is broken into four stages and lasts for around 90 minutes. If we sleep for 8 hours, we’ll enjoy 4-5 complete sleep cycles. Halve your time in bed, and you’ll halve your number of sleep cycles.
As you can imagine, this will impact you upon waking. Effects of only getting 4 hours of sleep include:
- Feelings of depression, anxiety, and irritability.
- Elevated heart rate
- Difficulty concentrating and ‘brain fog.’
The human body is pretty adaptable, but there are limits to what it can tolerate, especially concerning sleep deprivation. The journal Sleep published a study that found that regularly getting just 4 hours of sleep ages brain function by some eight years.
So, is getting just is 4 hours of sleep dangerous? If you try to make it your new routine, yes. You’ll get away with it for a day or two, but the risk of heart attacks and stroke is elevated in the longer term.
Practice superior sleep hygiene and work toward building yourself back up to 8 hours of sleep a night. Very few people, if any, can flourish on less sleep.
Is No Sleep Better Than 4 Hours of Sleep?
If you’re particularly late to bed one evening, you may wonder if it’s worth sleeping. This leaves you with a decision to make – pull an all-nighter vs. 4 hours of sleep. In truth, it’s always better to get some sleep, even if it is just 4 hours.
If you’re staring at the clock at 3 am, knowing your alarm is set for 7 am, get some sleep. You may still be exhausted in the morning, but you’ll have some ability to function that would otherwise be absent, and you’ll be considerably safer.
As explained by Occupational and Environmental Medicine, failing to sleep for 24 hours impairs brain function as much as alcohol intoxication. Even if you’re teetotal, you’ll operate akin to a blood alcohol level of 0.10%, which is high enough to land you a DUI.
How To Get Through The Day on 4 Hours of Sleep
If you’ve had a bad night’s sleep, it’s tempting to cancel the following day and stay in bed. Sadly, that’s rarely an option. You’ll likely need to get up and tackle your responsibilities for the next several hours.
After only 4 hours of sleep the night before, you may consider a nap during the day, but that can be a double-edged sword. A power nap of 15 to 20 minutes may sharpen you up. Fall into a deeper sleep, and you risk throwing your sleep schedule further off-kilter.
Here are some techniques to make it through a day after a night of just 4 hours of sleep:
1/ Wake Up on Time
If you haven’t slept well the night before, you’ll likely instinctively reach for the snooze button when your morning alarm sounds. Do all you can to resist this temptation. An extra 10 minutes in bed can make a difference to your energy levels, but not the way you expect.
If you hit snooze and fall asleep again, you’ll likely recommence a new sleep cycle. That means you’ll be wrenched from a deeper slumber when the alarm sounds again. This will make you even groggier than if you just got up in the first place.
If you must try to get extra sleep, consider setting your alarm for 30 minutes later than usual. That may allow you to squeeze in an extra sleep cycle overnight. Don’t expect miracles, as you’ll not feel the same as if you slept for 8 hours.
2/ Cold Shower
It’s important to understand how to wake up after 4 hours of sleep, as you’re understandably going to be pretty tired. Starting your day with a colder shower is a great way to spark yourself into life.
Medical Hypotheses explain how showering for 2-3 minutes at temperatures of 20OF is used as a treatment for depression. Think of a cold shower as a mild, humane form of electroshock therapy.
The cold water increases beta-endorphin and noradrenaline in the blood, which activates a range of electrical impulses in the brain. You’ll feel energized and content, with the bleary-eyed sleepiness of your poor sleep evaporating – at least in the short term.
A short burst of exercise before you start your day is another great way to recover from 4 hours of sleep. Like a cold shower, this will flood your body with endorphins and set you up for a day. There are caveats to exercising after poor sleep, though.
If you only completed two sleep cycles, your muscles didn’t undergo as much repair as they ordinarily would overnight. This means you should not attempt intense cardio or anything that will strain said muscles, such as weightlifting.
If it’s an option, walk to work instead of driving. If that’s not the case, take a brisk stroll around the block or even a light jog for 20 minutes. The key is to elevate your heart rate and release endorphins without putting yourself at risk of injury.
4/ Some Caffeine
For most people, caffeine is a non-negotiable on any morning. If you only slept 4 hours, it becomes even more critical. Limit caffeine intake, and don’t assume drinking 2-3 cups of coffee instead of 1 will help.
Consuming too much caffeine comes with a range of side effects. You’ll be jittery, irritable, and likely need the bathroom regularly because caffeine is a diuretic.
Too much caffeine will make you sleepy. Coffee and energy drinks block messages from adenosine, an inhibitory neurotransmitter that makes us feel tired. This is why caffeine makes us more alert, at least in the short term.
Adenosine can only be suppressed so much, and if you consume too much caffeine, the brain will panic and become flooded with this chemical compound. As a result, that extra cup of coffee will leave you exhausted and needing a nap, not feeling sharper.
5/ Set Realistic Targets for the Day
Think realistically about what you can achieve after 4 hours of sleep. Don’t force yourself to tackle the day as though you slept normally. Your reflexes will be sluggish, and your decision-making may be impaired.
Rewrite your to-do list for the day, whether for work or your personal errands, and ensure you only tackle the tasks that are safe and achievable. Everything else can wait until tomorrow.
6/ Prioritize Duties
If you’re at work, you won’t have the option of postponing all duties for 24 hours. While reviewing your list of tasks, tackle anything particularly ominous or challenging first. These jobs won’t get any easier later.
It’ll be tempting to procrastinate, but the reality is that you’re only going to grow more tired as the day goes on. Get the physically or mentally strenuous tasks out of the way first, and save the mundane duties for the afternoon.
7/ Eat Light And Avoid Sugar
You’ll probably be hungry after a poor night of sleep but resist the urge to seek out comfort food. A plate of heavy carbohydrates won’t energize you in any way. You’ll feel even more sluggish.
Avoid sugar if you didn’t sleep well. At first, the idea of a so-called “sugar rush” may be appealing – it’ll give you the energy to get through an important task. Remember that what goes up must come down, and you’ll experience a heavy mid-afternoon energy crash.
If you only slept for 4 hours the night before, eat light, little, and often the next morning—snack on superfoods such as fresh berries throughout the day.
Give your digestive system as little work as possible while keeping your energy levels up.
8/ Stay Hydrated
The Journal of the American College of Nutrition confirms that cognitive performance is impaired by dehydration, and you’ll be working from a lower base in the first place.
As discussed, too much caffeine will make you sleepy. Exchange coffee or energy drinks for bottled water as the day wears on. You may be surprised at how much sharper this makes you feel.
9/ Fresh Air
Take a minute or two to step outside into the fresh air as often as possible. This will be invigorating for your tired body, allowing you to soak in Vitamin D and enjoy a change of scenery that will restimulate your body and mind.
10/ Regular Bedtime
If you fail to sleep longer than 4 hours a night, you’ll start to build an unwelcome level of sleep debt, which is the accumulation of lost slumber. As per Scientific Reports, it can take as long as four days to fully repay a single hour of sleep debt.
Despite this, don’t try to force your body to make up for the sleep that you lost the next night. If you slept for 4 hours on Monday night, do not try to rest for 12 hours on Tuesday and expect this to balance the books.
If you don’t sleep enough one night and sleep too much the next, your sleep rhythms will remain off-kilter. The key to dealing with 4 hours of sleep is ensuring that your mind and body are prepared to sleep 8 hours, making it unlikely to happen again.
We all have bad nights of sleep on occasion, and there will be times that you need to function on just 4 hours of slumber. However, trying to make this your new routine is inadvisable. Treat your body with kindness and get sufficient sleep, as you’ll be more efficient in the aftermath.