The Altitude Impact on Sleep

Disrupted sleep happens to almost everyone who comes up from sea level, as the altitude impact on sleep is real. Breckenridge sits at 9,600 feet. Leadville is above 10,000. Even the towns that feel like foothills by Colorado standards, Vail, Telluride, and Estes Park, put you a mile and a half or more above the ocean. There's meaningfully less oxygen in every breath you take at a higher altitude, and your body notices, even while you're asleep.

Thin air, restless nights - Altitude Impact on Sleep

The most common effect of the altitude impact on sleep is to interrupt deep sleep. A review in the Journal of Applied Physiology found that reduced slow-wave sleep is a well-documented change in sleep structure among lowlanders at altitude. Slow wave sleep is the heavy, hard-to-wake-from phase that does most of the physical recovery work overnight, which is exactly what you want after a day of travel, hiking, and seeing new sites.

While researchers have not settled whether periodic breathing causes fragmented sleep, or whether both are just downstream of low blood oxygen, low blood oxygen is another documented side effect for visitors at high altitude. Your breathing falls into a cycle overnight, deep and fast for a stretch, then briefly shallow or paused, then deep again, and the transitions can surface you out of sleep without fully waking you up.

The current evidence points to oxygen as the main culprit. But all in all, the experience is the same, described as nearly universal for newcomers, with complaints starting at elevations around 8,000 feet, including trouble falling asleep, waking repeatedly, vivid dreams, and getting up in the morning still feeling tired.

The first night is the worst night

Wondering how long it’ll last? Just know your first night in the mountains is the roughest one you'll have. Your second is better. And beyond that, most people are much more acclimated and returning to regular sleeping patterns.

A study published in Sleep followed sixteen healthy mountaineers who slept one night at low elevation and then several nights in a mountain hut. On their first night up high, sleep efficiency dropped from 93 percent to 69 percent, and slow wave sleep fell from 18 percent of the night to 6 percent. By the third night, slow wave sleep had climbed back up, and the subjects reported feeling noticeably better in the morning. Their bodies had started to adjust.

That study took place at roughly 15,000 feet, far above any Colorado town, so the numbers are more dramatic than what a visitor to Crested Butte should expect. But the shape of the curve holds at Colorado elevations, too. Research at a more moderate altitude has found the same pattern of improvement between the first and second nights, as oxygen saturation rises and breathing settles.

Low humidity and sleep

Colorado's mountain air is exceptionally dry, and it gets drier in winter when the heat is running. You lose water through your breath all night without realizing it, which is part of why you wake up with a dry throat, a stuffy nose, or a nagging thirst that pulls you out of bed.

The dry air also encourages mouth breathing, which makes snoring worse for people who already snore and introduces it to people who normally don't. If you've ever been elbowed awake in a mountain rental by a partner who swears you've never snored like that at home, this could be why.

Tips for better sleep and acclimating

Start at a lower altitude. Starting your trip with a night in Denver at 5,280 feet, or in a mid-elevation town, will give your body a head start before you climb another 4,000 feet into the Rocky Mountains. A gradual ascent will act as a buffer and lessen the likelihood of altitude sickness.

Drink more water than feels reasonable. Not only should you hydrate before you arrive in Colorado, but it’s also recommended to drink about 1.5 liters more than you’d typically drink at lower altitudes, and even more if you’re active. For added support while you’re not on the slopes or out hiking, check for a humidifier in your cabin or hotel to boost moisture in the air.

Raise the head of the bed. Sleeping with your upper body slightly elevated makes breathing easier by keeping the airway more open. A wedge pillow works great for this, and bonus points if you stay somewhere with an adjustable bed. Sleep Basil, one of the local mattress stores in Denver, supplies mattresses to boutique hotels and short-term rentals, and has seen mountain properties get much more deliberate about their beds in this way.

Go easy on the alcohol that first night. Après-ski is real, and nobody is telling you to skip it. Just know that alcohol suppresses breathing and worsens the oxygen dip you're already fighting, and the first night is when you can least afford it.

When it's more than bad sleep (altitude sickness)

One honest caveat. If the sleeplessness comes packaged with a headache that won't quit, nausea, dizziness, or breathlessness while you're sitting still, those are signs of acute mountain sickness, and the fix is to descend. Most people who feel rough at altitude are simply tired and under-oxygenated, but it's really important to know where the line is so you can find relief and feel better sooner rather than later.

Sleep, eventually - It's Worth It

It’s true most visitors find that the mountains are worth a rough night. Anyone who has watched the sun come up over a valley at 9,000 feet knows the tradeoff is a fair one.

The goal is just to make it a choice. Get in a night at a lower elevation, drink your water, keep the room humid, prop your head up, and give your body the two or three nights it needs to catch up. Then, when you're awake at dawn in the mountains, it'll be because you wanted to see it.

Author: Phil Lotterhos

With over a decade of helping Colorado residents achieve better sleep, Phil Lotterhos is a consultative mattress expert and co-owner of Sleep Basil, a mattress store in Denver. Known for his educational, easy-going approach and belief that "materials matter more than brand names" in mattress construction, Phil combines deep product knowledge with a passion for helping people find their perfect sleep solution.