If you’re one of the nearly three in four Americans who struggle to get a restful night’s sleep, chances are you’ve used, or at least heard of, melatonin.

A hormone naturally produced in our brains, melatonin is commonly known as “the sleep hormone.” It is also one of the most popular over-the-counter sleep remedies on the market: Melatonin supplement use among Americans has increased four-fold since 2000.  

So what’s the catch? While melatonin may improve sleep for some people, most sleep medicine specialists agree that melatonin isn’t a one-size-fits-all, risk-free cure for sleep problems. “Sleep and sleep disorders are very individual,” says Michael Breus, PhD, a clinical psychologist known as The Sleep Doctor and a Fellow of The American Academy of Sleep Medicine. “Melatonin isn’t a panacea, nor is it suitable for everyone.” 

Keep reading to learn who may benefit — and who should stay away from — the so-called “vampire hormone.” 

What Is Melatonin?  

Melatonin is hormone that’s naturally released by the pineal gland, a pea-sized gland in the brain. Melatonin helps to regulate your 24-hour sleep-wake cycle — aka your circadian rhythm. As you might guess by its nickname (“vampire hormone”), the release of melatonin is triggered by darkness — in other words, it only comes out at night. When receptors in your retinas detect a lack of light, a signal is sent to the suprachiasmatic nucleus (SCN) in the hypothalamus to activate the pineal gland. 

“Melatonin levels rise in the evening, prompting physiological changes like lowered body temperature and respiration rate, signaling the body to prepare for sleep,” Breus says. Once melatonin is released into the bloodstream, physiological changes occur such as decreased body temperature and respiration rate, along with drowsiness. Levels typically stay elevated throughout the night before returning to negligible daytime amounts.

Regulating your sleep-wake rhythm seems to be its main function, but research suggests that melatonin might have other potential benefits (including anti-aging and anti-cancer properties) as well that aren’t fully researched or understood.

What Are Melatonin Supplements? 

Besides the all-natural version produced in your brain (also called endogenous melatonin), there are over-the-counter melatonin supplements available today (in certain countries — more on that below). You’ll typically find melatonin supplements in two main forms: natural and man-made. (Breus also notes there is a first-of-its-kind plant-based melatonin called Herbatonin.)

However, in this case, “natural” doesn’t necessarily mean safe. In fact, because natural melatonin supplements are created from animals, there’s a risk of contamination. That’s why it’s a safer bet to go for the synthetic form of the supplement. You should be able to find this labeled clearly on the supplement’s packaging, or ask your pharmacist or doctor if you’re not sure. 

Note: In most places in the European Union, New Zealand, Australia, and some other countries, you will need a prescription from your doctor to buy melatonin.  And in the U.S. and Canada, melatonin supplements are the only hormone that can be purchased without a prescription. Since it’s considered a dietary supplement, its safety and efficacy aren’t regulated by the Food and Drug Administration (FDA). (More on that below.) 

How Do Melatonin Supplements Work? 

Melatonin supplements work in a similar way as the natural hormone, helping the systems in your body align in the evening in preparation for rest, Breus says. As noted above, melatonin works by bringing about physiological changes – including lowered body temperature and respiration rate — that put your body in a quieter, drowsy state to promote sleep. When you take a supplement you’re adding to those physiological signals, Breus says. 

What many people get wrong is that melatonin doesn’t act like a prescription sleeping pill. It’s not a sedative, so it won’t quiet a busy mind or treat other issues that can cause insomnia. And unlike prescription sleep aids, you need to take it an hour or two before bed to see any effect. Many people take it right before bed or in the middle of the night, expecting it to knock them out, Breus notes — and it won’t.

What Foods Have Melatonin? 

While a few foods, such as tart cherries and walnuts, naturally contain melatonin and can modestly boost production of melatonin, melatonin levels are much more impacted by light.

There is another one ingredient in particular that can help improve melatonin levels: tryptophan, an essential dietary amino acid that’s a precursor to melatonin production. Tryptophan can be found in most protein-rich foods, especially lean protein, eggs, cheese, fish, seeds, nuts, and legumes.

Who Should Take Melatonin?

“A melatonin supplement can be effective in the right situations,” says Breus. “It works best when your internal clock has been thrown out of whack, like from jet lag or shift work, or if you have a circadian rhythm disorder, such as delayed sleep phase syndrom.” (In any case, Breus advises talking with your physician before taking melatonin.) 

Here are a few research-backed use cases for melatonin:

Jet lag: Melatonin has been shown help reduce jet lag by syncing your internal clock with the time change. One analysis of 10 studies deemed melatonin to be “remarkably effective” at reducing the effects of jet lag, and found “occasional short-term use” to be safe. (Find more science-backed strategies to manage jet lag here.)

Improving sleep efficiency: If you’re having a few restless nights and are trying to get more rest, studies  have found that melatonin may increase sleep efficiency by around 2 percent. Translation: You’ll fall asleep about 4 minutes faster, and sleep around 13 minutes longer (though that’s not much to write home about). 

Delayed sleep phase syndrome: Adults and teens with this sleep disorder have trouble falling asleep before 2 a.m. and have trouble waking up in the morning. Research suggests that a combination of melatonin supplements, a behavioral approach to delay sleep and wake times until the desired sleep time is achieved, and reduced evening light may even out sleep cycles in people with this syndrome. 

How Much Melatonin Should I Take?

Though there are no standardized dosages for adults, Breus suggests starting with a low dose of .1 to 5 mg and seeing how your body responds. Though supplements are sold up to 10 mg, that’s much more than your body needs, plus those larger amounts haven’t been studied, he notes.

Potential Drawbacks of Melatonin 

Because the FDA doesn’t regulate melatonin — or any dietary supplement, for that matter — it isn’t  tested for safety, potency, or effectiveness and can contain harmful ingredients, or an inaccurate ingredient list.

One study found that in more than 71% of melatonin supplements, the amount of melatonin was more than 10% different from what the product label indicated. Some products contained as much as 478% more melatonin than advertised.

Breus suggests asking your doctor or pharmacist for a recommendation rather than just plucking a random brand off the drug store shelf.

And, because melatonin hasn’t been studied for long-term use it’s not meant to be a solution for chronic sleep problems. Some sleep specialists recommend trying it for a couple of weeks, maybe a month or two, and see if that gets you back to a regular sleep cycle. If not, it’s a good idea to talk to your doctor about what’s keeping you awake.

Bottom line? Before reaching for a sleep genie-in-a-bottle, there are multiple ways that you can naturally improve your sleep.

You can take up a new practice like meditation, adjust your meal times to your body’s natural rhythm, or optimize your restorative deep sleep with one of these tips.

Who Should Not Take Melatonin? 

According to physicians at the University of North Carolina School of Medicine, people who are taking prescription steroid drugs; antiseizure medications; have heart disease, stroke, or high blood pressure; severe mental illness; or an autoimmune disease or immune-system cancers such as leukemia and lymphoma should not take melatonin without the close supervision of a physician.  

To that list Breus adds those who are on diabetes medication and women who are trying to conceive as well as pregnant women and nursing mothers. “There’s not enough research to confirm that taking melatonin while pregnant or breastfeeding is safe,” he says. “Because melatonin levels naturally rise throughout pregnancy, one potential risk of supplementing is giving your body too much of the hormone.”

Courtesy of OURA Team

Author: Janet Ungless  September 22, 2022

HRV is a powerful metric; it can give us unique insights into our body’s response to stress. In the scientific literature, higher HRV is typically associated with better health and improved performance [1]. But HRV isn’t as simple as, “How high can you go?”  — having more consistent HRV values from day to day can also signal an enhanced ability to respond to daily stressors [2].

With that in mind, how can you increase your HRV and make it more consistent?

Five Tips For Higher, More Consistent HRV

1.  Stay active.

One of the most effective ways to lower your resting heart rate and increase your HRV is staying active. Regular exercise a few times per week can lead to improved HRV at any age [3] and is one of the most effective, established ways to make progress for more sedentary individuals. If you’re already very active, rather than aiming for a higher HRV score, focus on incorporating HRV monitoring into your training routine and watch how your HRV consistency changes. This approach can lead to improved performance [4].

2. Get good sleep.

Good sleep is just as important as exercise. Several studies have shown how sleep deprivation, or simply lower sleep quality, is associated with reduced HRV [5]. So, especially when something like a new exercise regimen or work-related stress begins to add strain to your day — recovery becomes essential.

Check out Ten Tips for Better, Deeper Sleep to put yourself on the path towards a good night’s sleep.

3.  Eat well.

Activity, sleep, and diet are the three pillars of a healthy lifestyle. What we eat and when we eat can have a significant impact on our sleep and resting physiology (heart rate and HRV). While individual needs can vary, try avoiding processed foods and late, large meals, as these have been shown to reduce HRV [6].

4. Breathe.

Deep breathing techniques (everything from yoga, mindfulness, meditation, or biofeedback) can effectively strengthen the parasympathetic system (your “rest and digest” network), resulting in improved HRV. While putting these techniques into practice, keep in mind that your HRV is likely going to be higher during the activity itself than your nighttime values. This is especially true when breathing close to our resonant frequency, which is typically 6 breaths per minute [7].

The research is still emerging on if these daytime HRV increases can reliably improve your resting, nighttime HRV, but it’s one of the many tools you can access easily and is definitely worth exploring.

For some, the breathwork just works. Check out this example of HRV expert Marco Altini’s data showing an increase in weekly and monthly HRV while practicing deep breathing for up to 40 minutes a day.

5. Listen To Your Body And Better Manage Stress  

The previous four tips are all key to improving our HRV, but stress will still play a significant role in our lives for a variety of reasons. On days when your HRV is a bit lower than usual, try to prioritize recovery, reduce training intensity, and take extra care of yourself. These small steps can lead to improved health and performance [8].

Using Oura

If you have an Oura Ring, there are multiple ways you can explore how your body is responding to stress and start making adjustments that can improve your HRV:

• Look for sharp increases or drops in your average nighttime HRV; it can provide clues into how your lifestyle is impacting your body.
• Look for an upward trend in your nighttime HRV trace, a sign that your body is recovering while you sleep.
• Look for lifestyle practices that encourage HRV consistency in your HRV Balance.

HRV is Highly Individual

Many of these HRV tips have worked for a variety of people. However, HRV is highly individual, so remember to always compare your HRV to your own averages and avoid comparisons to others.

As often happens when we try something new, it’s also important to experiment and see what works for you, your body, and your lifestyle. Improving our physiology takes time; each of these habits might take several weeks to build and deliver  benefits, but exploration will only help you find what’s best for your health!

Courtesy of OURA Team

Author: Oura Team  February 26, 2021

About The Author

Marco is an HRV expert and data scientist with a background in computer science and physiology. Over the years, he has published more than 50 papers at the intersection between technology, health and performance.

If you’d like to follow Marco’s work, you can find him on Twitter @altini_marco.

References
[1] Kemp, A. H., & Quintana, D. S. (2013). The relationship between mental and physical health: insights from the study of heart rate variability. International Journal of Psychophysiology, 89(3), 288-296

[2] Flatt, A. A., Esco, M. R., Allen, J. R., Robinson, J. B., Earley, R. L., Fedewa, M. V., … & Wingo, J. E. (2018). Heart rate variability and training load among national collegiate athletic association division 1 college football players throughout spring camp. The Journal of Strength & Conditioning Research, 32(11), 3127-3134

[3] Sandercock, G. R., Bromley, P. D., & Brodie, D. A. (2005). Effects of exercise on heart rate variability: inferences from meta-analysis. Medicine and science in sports and exercise, 37(3), 433-439

[4] Javaloyes, Alejandro, et al. “Training prescription guided by heart rate variability vs. block periodization in well-trained cyclists.” The Journal of Strength & Conditioning Research 34.6 (2020): 1511-1518

[5] Spiegelhalder, K. A. I., Fuchs, L., Ladwig, J., Kyle, S. D., Nissen, C., Voderholzer, U., … & Riemann, D. (2011). Heart rate and heart rate variability in subjectively reported insomnia. Journal of sleep research, 20(1pt2), 137-145

[6] Young, H. A., & Benton, D. (2018). Heart-rate variability: a biomarker to study the influence of nutrition on physiological and psychological health?. Behavioural pharmacology, 29(2-), 140.

[7] Vaschillo, E. G., Vaschillo, B., & Lehrer, P. M. (2006). Characteristics of resonance in heart rate variability stimulated by biofeedback. Applied psychophysiology and biofeedback, 31(2), 129-142

[8] Granero-Gallegos, A., González-Quílez, A., Plews, D., & Carrasco-Poyatos, M. (2020). HRV-Based Training for Improving VO2max in Endurance Athletes. A Systematic Review with Meta-Analysis. International Journal of Environmental Research and Public Health, 17(21), 7999

Your sleeping heart rate curve is your heart’s personal signature. A lower resting heart rate (RHR) is a sign of quality recovery and health.

By looking at your resting heart rate (RHR) curve in your Oura App, you can see the effects of late meals, evening workouts, alcohol, sickness, being misaligned with your circadian rhythm, and more.

What Is Your Sleeping Heart Rate?

Nightly average RHR varies widely between individuals. A normal heart rate can range anywhere from 40 to 100 beats per minute (BPM) and still be considered average. It can also change from day to day, depending on your hydration level, elevation, physical activity, and body temperature. As with many of your body’s signals, it’s best to compare your RHR with your own baseline. Avoid comparisons to those around you.

When looking at your RHR curve, pay special attention to these three things:

• Your trend: Does your RHR go up, down, or stay level during the night?
• Your lowest point: When is your RHR lowest?
• Your end: Right before you wake up, does your RHR change?

With these questions in mind, here are four patterns you may recognize in the night-time heart rate curves you can see with Oura:

4 Types of Sleeping Heart Rate Patterns

The Hammock: Relaxed in Bed and Ready to Rise

The hammock curve shows an optimal overnight heart rate journey. During your initial sleep stages, your body relaxes and your blood pressure and heart rate begin to drop.

In this scenario, your lowest RHR occurs near the midpoint of your sleep, when the amount of melatonin present reaches a peak. If you are perfectly in sync with the sun’s patterns, your body temperature drops to its lowest level around 4 a.m.

Your RHR may momentarily rise during REM sleep. This is normal and you can ignore these temporary spikes when looking for the hammock curve during your sleep.

As you wake in the morning, your heart rate begins to rise. The hammock curve is a sign that your body was relaxed during the night and is ready to rise after a quality night’s sleep.

The Downward Slope: Your Metabolism Working Overtime

The Downward Slope is a sign that your metabolism is working overtime. Did you have a late meal, a late workout, or a glass of wine before bed? If your RHR starts high and reaches its lowest point right before you wake up, you may start the day feeling groggy.

If you regularly see this downward slope, it may be wise to stop and reassess your evening routine. For example, if you normally work out late at night, exercising  1–2 hours earlier can result in positive changes.

In the morning, getting fresh air and sunlight as soon as possible can help you get started on your day.

The Hill: Too Exhausted for Bed

If your RHR increases right after you fall asleep, this could be a sign of exhaustion. Did you go to sleep on time? If it’s past your regular bedtime, you may start feeling the effects of increased melatonin – a hormone that aids sleep – and lower blood pressure. This communication from your body serves as a warning of sorts, reminding you to get to bed on time.

If you did go to sleep during your ideal bedtime window, it’s possible that your heart rate may be increasing at the start of the night for reasons you can’t control. For instance, your airways may have relaxed during sleep, causing you to snore, which raises your heart rate.

Try adjusting your bedtime or addressing possible causes of congestion if you’re consistently seeing this curve in your sleeping heart rate.

The Uplands: Under Strain

A consistently elevated heart rate while asleep can indicate strain that is preventing your body from getting optimal rest and recovery. After a night with a heart rate pattern that looks like this, focus on giving your body a break — turn on Rest Mode, give yourself extra downtime, or an early afternoon nap.

Tips for Improved Sleep

When you’re sound asleep, your body is wide awake. Welcome its feedback, listen closely to what it has to say, and take steps towards optimizing your sleep.

Use the following tips to help boost your sleep routine:

• Try to wake up at the same time seven days a week. (Yes, that includes weekends.)
• Time your meals mindfully; late meals may show up as the Downward Slope.
• If your sleep pattern is optimal (Hammock Curve), take notes. Think about what you did (or didn’t do) the previous day and continue to make similar choices.

Courtesy of OURA Team

Author: Oura Team  March 16, 2023

Resting heart rate (RHR) refers to the number of times your heart beats per minute when you’re at rest. It can be a helpful indicator of your sleep quality, recovery, and overall health. 

In general, a lower RHR is a sign of good physical fitness and overall health, while a higher RHR suggests potential illness, stress, or something else is challenging your body. 

According to Mayo Clinic, most healthy adults can expect resting heart rates to range from 60 to 100 beats per minute. But what about Oura Members? 

Here’s what aggregate data shows across Oura Members of varying age and gender.

Lowest Resting Heart Rate 

In the graphs below, we’re analyzing members’ lowest resting heart rate — a single number that takes into consideration members’ baselines.

Overall, Oura members’ resting heart rates range from the mid-50s to mid-60s.  This chart shows that resting heart rate increases slightly until about age 60, at which point it levels off and lowers slightly. 

For female Oura members, the average lowest RHR is 58.1 and for men, it’s 54.5. 

As these charts show, women tend to have a slightly higher RHR than men. This has to do with the size of the female heart, which is typically smaller than males. Because a smaller heart pumps less blood with each beat, the smaller female heart beats at a faster rate to match the larger male heart’s output.

Average Resting Heart Rate 

These charts look at members’ average RHR captured during the night. 

Average heart rate patterns tend to follow similar patterns to lowest heart rate across age and gender distributions.

What Factors Affect My Resting Heart Rate?

Your RHR is affected by a number of factors, both in and out of your control.

To lower your resting heart rate, the best thing to do is to get regular cardiovascular exercise — walking, jogging, cycling, or swimming all count. Other tips include: 

• Go to bed at a consistent time.
• Avoid alcohol, caffeine, and smoking.
• Stay well hydrated. 
• Practice stress management techniques such as breathwork or meditation. Find some follow-along exercises in the Explore Tab in your Oura App. 

Courtesy of OURA Team

Author: Locke Hughes  September 19, 2022

What Are the 4 Stages of Sleep?

Each night you take a rollercoaster ride through the different phases of sleep. Though you’re unaware of what goes on while you’re snoozing, your brain and body are in an active state.

Each stage of sleep plays a different role in how you feel the next day. Read on to learn which stage helps your brain, which restores your body, and if you’re striking a good balance between the stages each night.

There are traditionally 4 stages of sleep: awake, light, deep, and REM sleep. Each one plays an essential role in maintaining your mental and physical health.

As you’re reading about sleep, you may also see the terms “NREM” or “NREM Stages 1-4.” These are simply other terms for the phases of sleep.

• REM sleep stands for “rapid eye movement” and can also be called “stage R”
• NREM (or non-rapid eye movement) sleep includes light and deep sleep stages, and may also be referred to NREM stages 1-4, with light sleep being NREM stages 1-2 and deep sleep encompassing NREM stages 3-4

What Happens in Each Stage of Sleep?

Each stage of sleep plays a different role in preparing your body for the next day.

Why Awake Time Matters

It’s normal to wake up some times during the night, whether or not you’re conscious of being awakened. In the Oura App, you’ll see your amount of Awake Time shown in your Sleep tab. The nighttime Movement graph also gives you an idea of how many times you wake up during the night (find it by tapping the arrow just below Sleep Stages to expand this view). A tall, white line indicates excessive movement, suggesting you were likely awake.

If you feel refreshed in the morning and energetic during the day, you most likely don’t need to worry about your wake-ups or movement during the night. However, if you’re feeling fatigued, it could be an indication of something that’s affecting your sleep quality, or an untreated sleep disorder like sleep apnea.

Why Light Sleep Matters

Despite its name, light sleep is no lightweight when it comes to your health. It’s a key stage of sleep that delivers benefits to your brain and body, including codifying memories and boosting creativity. And that’s nothing to sleep on, given that about half of your time asleep — about 50% — is spent in this stage.

Light sleep actually occurs in two stages: NREM stages 1 and 2 sleep. Think of NREM stage 1 as “falling asleep.” During this time, your muscles relax, your heart begins to slow down, and your body temperature dips. Your brain waves slow down, moving from a regular, rhythmic pattern to one with less frequent, less regular waves. Stage 1 sleep usually only lasts a few minutes.

NREM stage 2 sleep makes up the bulk of your NREM sleep. During this stage of sleep, your muscles relax, and may jerk. Your respiration and heart rate slow down, your body temperature drops, and your brain waves also slow down and increase in amplitude.

Why Deep Sleep Matters

Deep sleep, also known as slow-wave sleep, is the body’s most rejuvenating sleep stage. During deep sleep, which occurs in the third NREM (non-rapid eye movement) sleep cycle, your body gets busy repairing and restoring many systems, from your brain to your muscles.

During deep sleep, your body slows way down. Your heart rate and breathing are at their lowest rate, and your muscles are fully relaxed. Your brain’s electrical activity slows down into long, slow waves known as delta waves, hence the name “slow-wave sleep.” It’s difficult to be woken up during this stage — and if you do, you can expect to feel groggy and “out of it.”

Typically, deep sleep occurs within an hour of falling asleep and you usually get more deep sleep during the earlier part of the night.

Why REM Sleep Matters

During REM sleep, as the name suggests, your eyes move rapidly behind your closed eyelids, your heart rate speeds up, and breathing becomes irregular. Brain activity also speeds up, mimicking brainwave activity while you’re awake. You may also experience irregular, jerky muscle twitches as you dream, and it tends to be more difficult to wake up during REM sleep. To protect yourself from acting out dreams, your body can also a loss of muscle tone during REM.

While it’s no longer true that you only dream during REM sleep, studies suggest that about 80% of vivid dream recall results after arousal from this stage of sleep.

Research has shown that REM plays an incredibly important role in both emotional health and learning. “Essentially, REM is creating a revised mind-wide web of associations,” explains Matthew Walker, Ph.D., author of Why We Sleep. “We make connections during REM sleep.” Furthermore, getting enough REM sleep may help mitigate potentially negative emotional reactions.

What Does A Normal Night Look Like?

The amount of each of the 4 stages of sleep can vary significantly between nights and individuals. During an ideal night’s sleep, your body has enough time to go through four to five 90-minute cycles that sample different phases of sleep as the night progresses.

In general, each cycle moves sequentially through each of the 4 stages of sleep: wake, light sleep, deep sleep, REM, and repeat.  Cycles earlier in the night tend to have more deep sleep while later cycles have a higher proportion of REM. By the final cycle, your body may even choose to skip deep sleep altogether.

Overall, your body spends the majority of the night in light sleep. How much time you spend in REM or deep can vary widely by individual but below are the averages you can expect for each stage in a single night.

How Much Time Do You Spend in Each of the 4 Stages of Sleep?

Common Reasons for Disrupted Sleep Cycles

All stages of sleep are important and your body naturally regulates your sleep cycles to make sure you get what you need. Tools like the Oura Ring can help you monitor your sleep patterns and generate a Sleep Score each night to help you improve your sleep.

Check out these patterns to see if your sleep is being disrupted:

• Increase in deep sleep after a hard workout: Studies show that exercise can increase your body’s prioritization of deep sleep the night after an intensive workout.
• Higher REM rebound after sleep deprivation: When you recover from a period of sleep deprivation, your body prioritizes deep sleep for the first few nights to repair your body and prepare for action. After several nights of sufficient deep sleep, REM sleep rebounds  to focus on your brain.
• Interrupted sleep cycles after caffeine: Caffeine can increase the time it takes for you to fall asleep, cutting your sleep period short. Shorter sleep periods disproportionately cut down on your total REM sleep, as REM cycles are more likely to occur in later sleep cycles.

Taking a look at your nightly patterns (e.g. heart rate, body temperature) and acting on your desire to improve your sleep can help you face those days well rested.

Courtesy of OURA Team

Author: Oura Team  February 15, 2023