The flight attendants have just finished their safety briefing, the cabin lights are dim, and the plane slowly meanders its way toward the end of a long runway. As soon as engines roar, you can feel your eyelids droop, and you surrender to a brief snooze. As counterintuitive as it may seem, drifting off during takeoff is pretty common.
Registered dietitian nutritionist, sleep researcher, and founder of SunBright Wellness, Dani Dominguez, as well as Dr. Adam Shapiro, licensed pilot, sleep medicine specialist, and otolaryngologist, and founder of Aerospace Medical Sleep Consultants, share three primary reasons:
Adrenaline crash from travel prep
Packing, running errands, doing laundry, and navigating the airport chaos of stressors as you prepare for a trip. Sleep can also suffer if you’ve stayed up late to pack, set an early alarm for your flight, or simply couldn’t fall asleep due to nerves.
“Between the early wake-up times, getting through security, and rushing to the boarding gate, this could lead to overall fatigue and increase the likelihood that one will fall asleep on the plane,” explains Dominguez. “When an individual finally sits in their seat, it gives them the opportunity to slow down and relax.”
“Anxiety for the voyage can result in a paradoxical reaction with sleepiness, especially after the anticipation for takeoff has occurred,” adds Shapiro.
Symptoms of sudden exhaustion in relation to neuroticism and anxiety-depression have long been studied and documented, so it comes as no surprise that this is the body’s natural response to nervous system overload. The only difference is that the environment is more atypical than the norm. Instead of curling up on the couch or in bed to decompress, you’re in a metal container with hundreds of other passengers.
ASMR-like conditions
While we’re often creating environments that are most conducive to sleep in our own bedrooms, a plane, with its ASMR-inducing repetitive sounds, temperature, and visuals, can actually lend itself to catching coveted Zzz’s.
“Cabin vibration and the hum of the engines can have an effect of lulling someone to sleep,” reveals Shapiro.
“Right before the plane takes off, it creates a sense of ambiance where the lights are dimmed, the window shades are pulled down, and along with the white noise of the engine, it could trigger the body into sleep mode,” he adds. “As the plane gets moving onto the runway, the gentle movement and the low-frequency vibrations mimic subtle sensory inputs that promote relaxation and even sleep.”
Fascinatingly enough, the act of humming has been proven to be one of the biggest “stress busters” in existence. Though you, as a traveler, may not be the one humming, the aircraft’s noise and subtle trembles imitate the calming action and can be linked to this nearly instant state of calm.
Cabin air pressure
Perhaps the most scientific explanation for early fatigue is cabin air pressure, which is required to safely put a plane in the air at high altitudes.
“When you board the plane, the cabin is simultaneously being pumped with pressurized air mimicking an altitude between 6,000 and 8,000 feet above sea level,” shares Dominguez. “This process is imperative for airlines because the higher you go in the air, the less oxygen is available to breathe, and they want to prevent a hypoxic state.”
While the air onboard is generally cleaner and better filtered than many other modes of transportation (about 50% fresh air from outside and 50% recirculated cabin air through filters), oxygen availability (and not quality) is affected by cabin air pressure.
“This lower barometric pressure means the air molecules, including oxygen, are more spread out, even if the air itself is clean. As a result, there is less available oxygen per breath, which can lead to mild hypoxia in some individuals, causing symptoms like fatigue or drowsiness,” explains Dominguez.
Smokers, the elderly, and those who suffer from insufficient lung function will feel these effects even more than the average person, adds Thomas.
How to fall asleep on planes quicker
If you can’t relate to those who nod off as soon as they buckle their seatbelts, you’re not alone. In fact, you may not be genetically predisposed to fall asleep on an airplane at all.
“Ultimately, more research is needed, but there are several genes that have been identified that are known to regulate the internal circadian rhythm or body clock,” explains Dominguez, who also notes that our own DNA is hard-wired to assist with the timing and duration of sleep. “Not only can these genes influence whether a person is a morning person (early bird) or a late-night person (night owl), they can also impact whether a person is more flexible or adaptable to changes in their sleep patterns.”
As a result, one person may fall asleep more easily on a plane while another might struggle more to sleep due to their rigid circadian rhythms.
That said, tuning out distractions can be helpful for any type of passenger, and Dominguez offers a handful of quick tips to achieve quicker, higher-quality sleep:
- Drink plenty of water before and during your travel day. “This helps to prevent dehydration and the potential headache that could result from lack of fluids and, in turn, affect your ability to sleep.”
- Select a window seat that is near the wings of the plane. “This will not only allow you to lean against the window to sleep and have fewer disturbances, but this seat location will also reduce the bumpiness of the flight.”
- Adjust your sleep schedule leading up to your flight. “Gradually shift it to align with a closer time zone of your destination.”
- Pack sleeping essentials. “Earplugs or noise-canceling headphones, a sleep mask, a neck pillow, and enough layers or a blanket if you get cold.”
- Eat digestible and lighter foods. “Heavy meals can make it difficult to sleep.”
- Avoid alcohol. “While there is this preconceived notion that drinking alcohol on a plane will help you sleep, it could actually do the opposite. Not only is alcohol a diuretic, which can lead to dehydration since the body loses more fluids than it takes in, it can also disrupt your sleep architecture and alter the rhythm patterns, making it more fragmented.”
- Avoid caffeine. “Caffeine has been shown to block a sleep-promoting chemical called adenosine in the brain, which is essential for sleep regulation. If you want to have a successful time sleeping, it would be best to limit caffeine intake well before stepping onto a plane.”
- Limit screen time. “[Shutting down] approximately 30 minutes to one hour before sleeping on a plane could help reduce circadian rhythm disruption. Excessive screen time, especially blue light, can suppress melatonin, a hormone that naturally encourages sleep production in the brain, making it harder for a person to fall asleep.”
- Mimic the routine you have at home. “If you need to change into more comfortable clothing, read a book or even listen to the same music you fall asleep to, this will help the body transition into sleep easier on the plane because it recognizes the routine.”
- Be mindful of over-the-counter sleep aids. “Even though they may help you achieve sleep, they could be contributing more to the jet lag symptoms, such as grogginess and impaired cognitive function, because they can linger in the body well after deboarding the plane.”
Ready for takeoff
Falling asleep on a plane is nothing to be concerned about — in fact, many other travelers may envy you — but be sure to hydrate, find a comfortable sleep position that won’t give you an achy neck, and keep as close to the time zone of your destination as possible. Lean into this moment of calm and, if flying long distances, follow the aforementioned tips to further encourage a restful journey.
