5 Scientific Tricks to Fall Asleep Fast When You Can’t Sleep, According to a Sleep Expert.


Nearly two-thirds of adults in developed nations fail to meet the nightly eight hours of sleep recommended by the World Health Organisation.

According to Matthew Walker, sleep expert, professor at the University of California, Berkeley and neuroscientist, driving while drowsy is more dangerous than drunk driving. [1]

Sleep deprivation may also affect male and female fertility. Walker notes that men who sleep five hours a night have significantly smaller testicles than those who sleep eight hours or more. And, they tend to have levels of testosterone similar to a man ten years older. [2]

Sleep deprivation also increases the risk of cancer, memory loss, depression, anxiety, obesity, cancer, heart failure, Alzheimer’s disease and early death.

In his New York Times bestselling book, Why We Sleep (Audiobook), Walker notes that:

“After being awake for nineteen hours, people who were sleep-deprived were as cognitively impaired as those who were legally drunk… After sixteen hours of being awake, the brain begins to fail. Humans need more than seven hours of sleep each night to maintain cognitive performance. After ten days of just seven hours of sleep, the brain is as dysfunctional as it would be after going without sleep for twenty-four hours.”

An extra hour or two of sleep could also be the difference between being good versus great with your work, health, family, relationships and finances.

Here are five scientific tricks to help you fall asleep fast and regain these extra hours of sleep.

1. Maintain a consistent sleep schedule

Sleep expert, Walker, notes that one of the best ways to train your body to fall asleep quicker is to go to bed and wake up at the same time every day, even if you don’t have a good night of sleep.

Walker recommends that you set a bedtime reminder on your phone an hour before you plan to fall asleep.

Another effective trick is to develop a pre-sleep routine that will help you to build the habit of falling asleep quicker.

For example, during my pre-sleep routine, I spend five minutes stretching and practicing breathing exercises. Then I read a book in bed and usually fall asleep within 10 minutes of reading.

Experiment with different pre-sleep routines to find what works best for you.

2. Create a dark sleep environment

We live in a dark-deprived society, but we require darkness in the evenings to aid the release of a melatonin, a hormone that determines the healthy timing of our sleep.

The blue lights that emit from your electronic devices could fool your brain to think it’s still day time, even though it’s nighttime and you’re trying to sleep.

According to Walker:

“Even a hint of dim light—8 to 10 lux—has been shown to delay the release of nighttime melatonin in humans…A subtly lit living room, where most people reside in the hours before bed, will hum at around 200 lux. Despite being just 1 to 2 percent of the strength of daylight, this ambient level of incandescent home lighting can have 50 percent of the melatonin-suppressing influence within the brain.” (Source: Why We Sleep)

Walker’s advice is to dim down half the lights in your home and shut down all electronics about an hour before you go to bed. This way you can design your environment to make it easier to fall asleep fast.

3. Keep your body cool

According to Walker, our bodies require a drop in temperature—which affects our melatonin levels—to fall asleep quicker.

If you’ve ever woken up, only to find your arms and legs sticking out of your covers, it’s a sign that your body attempted to reduce its core temperature low enough for you to fall asleep.

The ideal bedroom temperature lies between 65 to 68 degrees Fahrenheit, assuming standard bedding and clothing.

Another trick to reduce your core temperature and fall asleep quicker is to take a hot bath before bed.

Walker suggests that:

“When you get out of the bath, those dilated blood vessels on the surface quickly help radiate out inner heat, and your core body temperature plummets. Consequently, you fall asleep more quickly because your core is colder. Hot baths prior to bed can also induce 10 to 15 percent more deep NREM sleep in healthy adults.”

4. Avoid caffeine and alcohol after 2 p.m

When we wake up in the morning, a chemical, adenosine, builds up in our brain to create sleep pressure and make us feel sleepier the longer we stay awake.

After about 16 hours of staying awake, the sleep pressure created by adenosine causes us to feel tired enough to fall asleep. But, caffeine creates the opposite effect.

After a dose of caffeine, say from a cup of coffee, caffeine latches onto one of the adenosine receptors in the brain and masks the receptor.

And so, after about 16 hours of staying awake, your brain is fooled into thinking that it hasn’t been awake for 16 hours, despite how sleepy and tired you feel. This is because caffeine is blocking the brain signals of adenosine, as well as the sleep pressure instructions to the brain.

The longer caffeine blocks adenosine, the sleepiness chemical, the greater the quantity of adenosine build up in your system. When your body rids itself of the caffeine from its system, not only do you revert back to the same level of sleepiness prior to consuming the caffeine, you’re also hit with an additional dose of sleepiness from the adenosine build up. This is the ‘caffeine crash’ you may have experienced before.

And just like any bad habit, you’ll crave another dose of caffeine to boost your energy, reinforcing the vicious cycle. [3]

The average half-life of caffeine is approximately five to seven hours. That’s why Walker recommends that we avoid caffeine consumption after 2 p.m.

In Why We Sleep, Walker also suggests that consuming alcohol, even wine or whiskey in the evenings, is detrimental for quality sleep:

“…those who had their sleep laced with alcohol on the first night after learning suffered what can conservatively be described as partial amnesia seven days later, forgetting more than 50 percent of all that original knowledge.”

Alcohol causes multiple sleep interruptions in the middle of the night, most of which we won’t remember. Plus, it blocks our REM and dream sleep, which is critical for mental health. [4]

5. Don’t stay in bed after you wake up

Here’s a common scenario.

You suddenly wake up an hour or two before the alarm to wake up rings. The clock is ticking. You know that time is running out and if you don’t fall asleep now, you’d miss out on the extra sleep.

But for some reason, you’re filled with anxiety because you can’t sleep and you’re not sure whether to stay in bed or get up and start your day.

Our brains are extremely adaptive, so if we spend enough mornings in bed after we wake up, the brain would learn to associate the bed with staying awake, instead of falling asleep.

Walker suggests that the best way to avoid this problem is to go to another dim lighted room and read a book until you’re about to fall asleep, then return back to bed.

If you still can’t fall asleep, that’s okay. By restricting time spent in bed, you can build up sleep pressure to fall asleep faster overtime:

“One of the more paradoxical CBT-I methods used to help insomniacs sleep is to restrict their time spent in bed, perhaps even to just six hours of sleep or less to begin with. By keeping patients awake for longer, we build up a strong sleep pressure—a greater abundance of adenosine. Under this heavier weight of sleep pressure, patients fall asleep faster, and achieve a more stable, solid form of sleep across the night. In this way, a patient can regain their psychological confidence in being able to self-generate and sustain healthy, rapid, and sound sleep, night after night: something that has eluded them for months if not years. Upon reestablishing a patient’s confidence in this regard, time in bed is gradually increased.”

Walker also suggests meditation as a solution to fall asleep faster, especially after a long flight and build up of jet lag. In particular, breathing exercises quiet the mind and weaken the fight-or-flight branch of the nervous system, a key feature of insomnia.

Master the Art of Falling Asleep

“Sleep that knits up the ravell’d sleeve of care, The death of each day’s life, sore labour’s bath, Balm of hurt minds, great nature’s second course, Chief nourisher in life’s feast.”

-William Shakespeare, Macbeth

Falling asleep is as much an art as it is a science. Whilst these scientific tricks can help you fall asleep faster, they aren’t rules set in stone.

As with everything, you can always experiment and find what works best for you based on your lifestyle and circumstances.

The main takeaway is that sleep is crucial for a healthy, productive and fulfilling life.

Make sleep a priority in your life today.


1. Why We Sleep: The New Science of Sleep and Dreams, by Matthew Walker

2. University of Chicago Study showing effect of 1 Week of sleep restriction on testosterone levels in young healthy men.

3. Caffeine sensitivity could be affected by several factors including age, quantity of prior sleep and medications taken. A. Yang, A. A. Palmer, and H. de Wit, “Genetics of caffeine consumption and responses to caffeine,” Psychopharmacology 311, no. 3 (2010): 245–57,

4. Studies also show that in pregnant women, alcohol could dampen the intensity of REM sleep experienced by the fetus, as well as reduce the breathing rate of the unborn baby.

5. Fun fact: According to the National Sleep Foundation, some people sleep better with their significant other in bed with them. However, approximately 30 percent of couples sleep in separate rooms.