Understand and Track Your Menstrual Cycle Phases

The menstrual cycle impacts women’s life on a monthly basis. So how to track it and its effects? In this article, PhD Jana Podlipská from the Oura science team explains how the menstrual cycle affects women. She also shows how the data you’ll see in the Oura app and Oura Cloud reveals some of the effects.

Most women are familiar with this: at certain times of month, you feel physical discomfort, tiredness or moodiness. Sometimes words like cranky or irritated have even been used (many times leading to even increased crankiness and irritation, must add). It has to do with your menstrual cycle, of course.

But why is it so, why does the menstrual cycle affect women like that? The answer is quite simple: Every woman who goes through the cycle every month is experiencing a rollercoaster of hormonal fluctuations. The hormones have an impact on both your physiology and behavior.

The new Oura ring features body signal tracking that can help you monitor your menstrual cycle and see some of the ways it affects your body.

In this article you’ll learn:

  • What are the phases of menstrual cycle, and how they affect your body
  • How you can track your menstrual cycle with the new Oura ring
  • What are the tips and tricks to relieve some of the monthly discomfort

The menstrual cycle and all physiological changes related to it are, of course, highly individual. Many issues ranging from the use of contraceptives to physiological conditions have an influence on the cycle, its effects, and how much you can track them.

The Menstrual Cycle Phases

Before digging deeper into the outcomes of the hormonal fluctuations women face, let’s revisit the basics of the menstrual cycle.

Menstrual cycles

Menstrual cycle, hormone levels and body temperature deviation. Source:https://commons.wikimedia.org/wiki/File:MenstrualCycle2_en.svg

The menstrual cycle starts with the first day of menstruation and usually lasts from 21 to 35 days, the average duration being 28 days. The cycle can be divided into two main phases: pre-ovulatory (i.e. follicular) and post-ovulatory (i.e. luteal). Ovulation marks the midpoint of the cycle.

Monthly Hormonal Fluctuations

The pre- and post-ovulatory phases of the cycle are characterized by specific hormonal changes that affect the physiology of women’s bodies. [Ecochard 2015]. During the pre-ovulatory phase, the levels of a hormone called estrogen are gradually increasing. Together with follicle-stimulating hormone (FSH), estrogen prepares the woman’s body for possible pregnancy.

By the end of the pre-ovulatory phase, another player called luteinizing hormone (LH) surges and triggers ovulation. The ovulation day can be used as a benchmark for days with the highest probability of becoming pregnant. The fertility window span starts generally 3–5 days before the ovulation and ends on the ovulation day. [Ecochard 2015]

In the post-ovulation phase, a hormone called progesterone dominates the menstrual cycle. It rises to its maximum level mid post-ovulation phase. (In case you don’t get pregnant.)

The Effects of Monthly Hormonal Fluctuations

Physical discomfort and mood swings are very common for most women who go through the menstrual cycle. The cyclic hormonal fluctuations are the main reason why women are glowing on one week, and feel low, oversensitive, sad or angry on another.

At mid-cycle, just before the ovulation and when the estrogen hormone reaches its optimal amounts, women usually feel at their best. In studies, they’ve for example reported high levels of well-being and self-esteem [Farage 2008].

During the late post-ovulatory phase (about a week before menstruation), the fast decline in both estrogen and progesterone hormones starts to negatively manifest itself. This is the time when many women may experience tender or lumpy breasts, fluid retention, bloating, cramps, cravings, mood swings, tiredness or anxiety.

According to research, about 80% of women experience some of these symptoms up to some level. Based on the symptom severity, about 30% of women are diagnosed with premenstrual syndrome (PMS) and 3–8% suffer from premenstrual dysphoric disorder (PMDD).

How to Track the Menstrual Cycle Phases with Oura

So, how is this natural mechanism of menstrual cycle reflected in your body’s physiological changes? And how can you detect those changes with the Oura ring?

There are several body signals that the Oura ring tracks which can help you follow what happens in your body during the cycle:

  • Body temperature deviation
  • Resting heart rate
  • Heart rate variability
  • Respiratory rate

A combination of these measures draws a picture about the current cycle phase, approximate cycle length, and the potential mood swings. Moreover, it may even help you to track your fertility. But bear in mind that fertility is such a complex topic that a lot of further research is needed before anything specific can be said about it, let alone make any prognoses.

Body Temperature Deviation

Body temperature is one of the core physiological players affected by estrogen and progesterone hormone fluctuations during the cycle. It has been shown that estrogen promotes the widening of blood vessels, heat dissipation and lower body temperatures. Conversely, progesterone promotes the narrowing of the blood vessels, heat conservation and higher body temperatures [Charkoudian 2017].

What this means in practice is that during the menstrual cycle, as the hormonal levels vary, body temperature varies as well. The body temperature increase in post-ovulation phase can be anything between 0.3–0.6°C in comparison to the pre-ovulation phase [Baker 2007, Shilaih 2017].

Each night, the Oura ring measures your peripheral body temperature and displays it as temperature deviation with reference to your temperature baseline. For most women with a menstrual cycle, the monthly body temperature variation has a biphasic shape/rhythm. Here’s how it looks like in the Oura app:

A phone with the Oura app

And here’s how the temperature trend looks like in Oura Cloud.

Temperature deviation graphThe graph illustrates the weekly temperature deviation of a woman with menstrual cycle length 28 days. Low peaks and areas under the temperature baseline (0.0 °C) correspond approximately to the pre-ovulation phase. High peaks and areas above the temperature baseline correspond approximately to the post-ovulation phase.

On a physiological level, the graph shows how in the pre-ovulation phase, when estrogen hormone is dominating, body temperature slightly decreases and reaches the lowest point around the ovulation time. After ovulation, when the progesterone levels increase, body temperature rises and peaks around the mid phase, dropping again towards the end of the cycle.

Resting Heart Rate, Heart Rate Variability, Respiratory Rate

The menstrual cycle affects also women’s cardiovascular system and respiratory rate. Several studies have indicated an increase in heart rate, decrease in heart rate variability and elevation of respiratory rate throughout the menstrual cycle [Tenan 2014, de Zambotti 2013, Brar 2015].

Why is that? First of all, your heart rate and respiratory rate are controlled by your autonomic nervous system. It, in turn, is linked to your hormonal fluctuations during the menstrual cycle [Brar 2015, Tenan 2014].

The autonomic nervous system has two branches: the stimulating sympathetic (also called as fight-or-flight), and the inhibiting parasympathetic (also called rest-and-digest). During the pre-ovulation phase, parasympathetic nervous activity usually increases. This leads to a calming effect on women’s physiological functions, and therefore lower heart rate, respiratory rate and higher heart rate variability.

Conversely, the sympathetic activity dominates later in the cycle, explaining the elevation in heart rate, respiratory rate and a decrease in heart rate variability. [Tenan 2014, de Zambotti 2013, Brar 2015].

Average hr and temperature deviation graphThe graph above nicely demonstrates the synchronization of resting heart rate (purple curve) with body temperature deviation (orange curve) across the menstrual cycle. Lower resting heart rate and body temperature occur during pre-ovulatory phase, whereas higher resting heart rate and body temperature occur during post-ovulatory phase.

HR and temperature deviation graph

This graph, on the other hand, shows the weekly average values of heart rate variability (purple curve) and body temperature deviation (orange curve). We can see that the heart rate variability behaves pretty much conversely to the body temperature. It has higher values during the pre-ovulatory phase when body temperature decreases and lower values during post-ovulatory phase when body temperature is higher.

Respiratory rate and temperature deviation

The third graph shows weekly average values of nocturnal respiratory rate (purple curve) and body temperature deviation (orange curve). Respiratory rate follows the body temperature pattern across the menstrual cycle. Respiration is slower at the beginning of the cycle when temperature is low and speeds up towards the end of the cycle as temperature rises.

Hormonal Contraceptives

What if you’re using combined hormonal contraceptives? Exogenous hormones, i.e. oral contraceptives, keep both estrogen and progesterone elevated across the menstrual cycle and therefore the body temperature stays relatively stable in a long term [Baker 2001]. Absolutely, the temperature values are approximately equal to body temperature during the luteal phase [Baker 2001].

Temperature deviation
Similarly, the cardiac function seems to be unaffected by the oral contraceptives due to the constant dosage of female hormones resulting in low variation in HR and HRV across the cycle [Teixeira 2015].

How to Fight Off PMS?

One of the burning questions many women might have is how to fight off the not-so-pleasant symptoms of the hormonal fluctuations? There are luckily some ways to ease some of the discomfort.

Exercise

Exercise makes you happy. During physical activity, your body releases hormones called endorphins which boost your mind and make you feel good. Moreover, endorphins reduce pain perception, thus aiding to fight physical aches. Try yoga, walking, jogging, swimming or working in the garden. Anything you enjoy and that makes you smile!

Eat well, regularly, and in small portions

Following healthy eating habits, also while you are craving for sweets or other junk food, will pay off. Large meals and meals rich in carbohydrates cause blood sugar swings which may worsen the emotional instability.

To keep your blood sugar levels stabilized, try to choose a meal that has quality protein (such as fish, lean meat or legumes) with whole grain sides and plenty of veggies. Try also to stick with healthy snacks such as nuts or fruits. Too much salt or sodium, both common in processed foods, will exacerbate water retention and possible swelling. Also caffeinated drinks, such as coffee or energy drinks, may leave you feeling more anxious and stressed. Therefore, you might want to consider trying out herbal teas such as chamomile or lemon balm to soothe your nervous system.

Sleep well

Adults need in general between 7–9 hours of sleep per night. Make sure you get as much quality zzz as your body craves to keep your mood lifted and to leave anxiety, tiredness and irritation at the bay.

Do you want to know more about body temperature tracking with the Oura ring? Check out What can you learn from your body temperature trends article.

Sources:

https://www.mayoclinic.org/healthy-lifestyle/womens-health/in-depth/menstrual-cycle/art-20047186

https://www.menstrupedia.com/articles/physiology/cycle-phases

http://teachmephysiology.com/reproductive-system/development-maturation/menstrual-cycle/

https://www.avogel.co.uk/health/periods/symptoms/mood-swings/

https://en.wikipedia.org/wiki/Premenstrual_syndrome

Ecochard, R et al. Self-identification of the clinical fertile window and the ovulation period. Fertility and Sterility, 2015 May;103(5):1319-25.e3.

Farage, MA et al. Cognitive, sensory, and emotional changes associated with the menstrual cycle: a review. Arch Gynecol Obstet. 2008 Oct;278(4):299-307.

Baker, F at al. Sleep and 24 hour body temperatures: a comparison in young men, naturally cycling women and women taking hormonal contraceptives. J Physiol. 2001 Feb 1; 530(Pt 3): 565–574.

Charkoudian N et al., Autonomic control of body temperature and blood pressure: influences of female sex hormones. Clin Auton Res. 2017 Jun;27(3):149-155.

Baker, F at al. Circadian rhythms, sleep, and the menstrual cycle. Sleep Med. 2007 Sep;8(6):613-22.

Shilaih M et al. Modern fertility awareness methods: Wrist wearables capture the changes of temperature associated with the menstrual cycle. Biosci Rep. 2017 Nov 24.

Tenan MS, et al. Changes in resting heart rate variability across the menstrual cycle. Psychophysiology. 2014 Oct;51(10):996-1004.

de Zambotti, M el al. Autonomic regulation across phases of the menstrual cycle and sleep stages in women with premenstrual syndrome and healthy controls. Psychoneuroendocrinology. 2013 Nov;38(11):2618-27.

Brar TK, et al. Effect of Different Phases of Menstrual Cycle on Heart Rate Variability (HRV). J Clin Diagn Res. 2015 Oct;9(10):CC01-4.

Baker, F at al. Oral contraceptives alter sleep and raise body temperature in young women. Pflugers Arch. 2001 Aug;442(5):729-37.

Teixeira, AL et al. Heart rate variability across the menstrual cycle in young women taking oral contraceptives. Psychophysiology, 52 (2015), 1451–1455.

Why I Chose the Oura Ring | Ben Greenfield

In the final moments before the Biohacker Summit 2017 in Helsinki, we had a quick chat with personal trainer, biohacker, speaker and performance coach Ben Greenfield about how and why he uses the Oura ring. He has written extensively on the Oura ring on his site: bengreenfieldfitness.com so if there’s something more you’d like to know be sure to check out his site.

Why do you track your sleep, activity and readiness stats?

I track them because I want to know what’s working and what isn’t when it comes to the workouts that I choose, the supplements that I take, the type of diet that I eat… and anything that I do to improve my body and my brain.

I want to know what’s working and what isn’t when it comes to the workouts that I choose, the supplements that I take, the type of diet that I eat…

For example, if I want to sleep better and I take something like NyQuil, a popular antihistamine for sleep, I can sleep through the night. But when I use my Oura ring to check on my deep sleep, for example, taking an antihistamine before bed completely destroys my deep sleep levels. And although I’ve slept through the night I wouldn’t know that I’ve lost on all that deep sleep if I wasn’t informed about it by the data from something like the ring.

Or I can determine how soon before a bedtime a hard workout keeps my body temperature high enough to where it’s elevated based on the Oura ring data. And if I really want to take things to the next level I could, for example, correlate the relationship between something like body temperature and deep sleep using the Oura Cloud dashboard screen. I could find out that if I exercise sooner than 3 hours before bedtime – and I’ve found this out by the way – my deep sleep suffers and that it’s likely related to the fact that my body temperature and my heart rate variability through the night both suffer, as measured by the Oura ring. The body temperature goes up, which it shouldn’t during the night, and my heart rate variability goes down.

Those are just some simple examples of metrics that I personally pay attention to. In addition, I like to look at my daily activity simply because it’s kind of like a pat on the back or a Pavlovian response when I see that I’ve reached my goal for the day.

What choices or changes have you made based on the data the Oura ring gives you?

I track my Readiness Score. Based on my Oura Readiness Score, I can choose to do yoga or an easy walk in the sunshine that day, rather than a hard-charging CrossFit workout or a high-intensity interval training workout.

In terms of long-term data trends and changes that I’ve made to my routine… One thing that I’ve found is that the Oura ring will track my respiratory rate and my resting heart rate. What I’ve found is that when I pay attention to deep breathing patterns and deep belly breathing during the day rather than shallow chest breathing, I can see direct correlation between a drop in my respiratory rate, when I’m looking at the trends on Oura, and a drop in my heart rate accompanied by an increase in my heart rate variability and an increase in my sleep efficiency.

That tells me that the engagement of better breathing patterns is a very smart move that I should prioritize.

What made you choose Oura as a tracking device?

Frankly, two things. The extremely high accuracy of the sleep data. And the ability to turn off the signal from the Oura so that I’m not bombarding my body with a Wi-Fi signal or a Bluetooth signal which most other self-quantification devices generate every 1–3 seconds.

What should people remember when analyzing their data?

The main thing is not to get too obsessed with the data. There’s actually a very good new book, called Unplugged about this. I would rather glance quickly at my data and get the minimum effective dose of data and the most benefit from the data I can in a short period of time. Rather than spend, say, 15 minutes pouring over my dashboard each day… Minutes that could be better spend with family or cooling down after a workout or getting a little bit of a more quality workout in or playing my guitar.

The main thing is not to get too obsessed with the data

You need to be careful to strike a balance between glancing at the data and having it briefly inform you in a very time-efficient manner and obsessing and pouring over the data in a way that almost strips you away from enjoying the other aspects of having a balanced life.

The final thing I’d recommend when you’re analyzing your data is to get an objective viewpoint of your data. That’s what many of my clients do. They give me access to their dashboard or they take a quick screenshot and upload it to their Instagram account that they share with me. And I’m able to look at it and give them recommendations on trends they might not otherwise have identified. So using a coach or a trainer to help look at your data is something I would recommend that you do.

Check out what Ben had to say at the Biohacker Summit 2017:

Watch video


If you’re interested in tracking your sleep and you don’t yet have the tools for it, have a look at the Oura ring in the Oura Shop. If you have an Oura ring, have a look at our Sleep FAQ for more answers or dig deep into your data in the Oura Cloud Beta.

How to Measure Readiness | Get to Know the Oura Readiness Score

Am I ready to take on the day? Should I take it easy today or go all out? How can I measure my readiness? These are questions many of us ask ourselves, yet so far it hasn’t been easy to objectively measure our readiness to perform.

 

Oura’s mission is to guide you to understand how your body responds to your activities, daily choices and rhythms, instead of just measuring individual metrics like steps or heart rate. This mission puts readiness into the very heart of Oura, and that’s why we want to give you an introduction into what readiness is, how you can measure it, and how the Oura ring and app can help you to prepare yourself so that you are ready – whatever the challenge.

What You’ll Learn in This Article

  • How to overcome the challenges of measuring readiness
  • How to measure readiness with the Oura ring
  • What factors Oura takes into account when calculating Readiness Score

What is Readiness?

What do we talk about when we say readiness? Readiness is our ability to perform at our best, both mentally and physically.

Readiness has much to do with how recovered we are, and in the end, with our overall health. The signals of our autonomic nervous system, such as Resting Heart Rate (RHR) and Heart Rate Variability (HRV), are among the most common indicators of readiness. They show us how our bodies respond to the demands of our daily life. If our load and recovery are in balance, our readiness is doing just fine.

Readiness isn’t static. No one can perform at their best 24/7/365 because our mental and physical readiness varies from day to day. Some days are perfect for challenging our bodies and minds, whereas on other days it might be wiser to focus on taking it easy.

The Problem: How to Measure Readiness

So far we’ve stated that readiness has to do with our recovery and health and it’s not static. But how can we measure readiness? And not only that… How can you measure your readiness?

We’re all unique – in lifestyle, fitness, thoughts, favorite TV show, recovery, health, sleep patterns, and yes, readiness. General guidelines on how to maintain or improve our readiness may work for some people, some of the time. Sticking to a regular sleep schedule is advisable but always going to bed at 10pm will not work for everyone.

Readiness is always a matter of the particular individual. Generalizations aren’t enough.

The current state of your body and mind does give you hints about your current readiness. Are you relaxed or tense? Is your mind clear as a crystal or covered in thick fog? Do you feel healthy or a bit under the weather? These are mainly subjective evaluations of your readiness.

Traditionally, you have needed to make some extra effort to get objective measurements. Tracking readiness has to do with the autonomic nervous system. In order to understand what’s going on, you need a reliable way to get data on its different functions. In practice, this has typically meant things such as adding a HRV measurement to your morning routines, or having specific periods of time when you log your resting heart rate, for example. (If you’re an athlete, you probably know what we’re talking about). The problem is that you only get a limited glimpse into your body signals.

Generally speaking, measuring readiness has so far had these downsides:

  • Generalizations don’t give you enough data
  • Gaining data has required extra effort
  • The results usually represent data from short periods of time

Tracking Readiness With the Oura Ring

We at Oura want to provide you a simple solution that helps you to understand your own, unique readiness. We believe that when you get relevant, personalized and actionable insights that are based on the reactions of your own body, you will learn more about yourself and learn to make choices and adjustments towards better readiness.

We also believe that you should be able to know how ready you are every single day and month. The idea behind the Oura ring’s design is that it’s so comfortable and unobtrusive that you can wear it around the clock. The ring does all the measuring without you even noticing it.

How well you sleep is in the core of the Oura readiness tracking. When you sleep, your body and mind recover and recharge – that’s when you build your readiness. Measuring your nighttime body signals therefore reveals invaluable data about your ability to perform during the following day. Another cornerstone of Oura readiness tracking is your daytime activity and load.

Oura analyzes your night-time and daytime data and tells you how ready you are. But it’s not just single days and nights, or individual metrics, that it uses gauge your readiness. Instead, it combines short- and long-term data: for example, what has your load been during the past 7 days. You will get not only a snapshot of your readiness status, but also a deeper understanding of your overall wellbeing.

The Readiness Score

Every day Oura gives you a personal Readiness Score that is your daily readiness signpost. It ranges from 0–100%, and is based on metrics (also known as contributors) tracked with the Oura ring.

Please note that even though your Readiness Score is specific to you, a rule of thumb is that if your Readiness Score is above 85%, you’re ready to meet the day’s challenges. If it’s below 70%, you might want to consider concentrating more on recovery.

What Does Oura Track to Help You Measure Your Readiness

Here are the contributors Oura uses to calculate your Oura Readiness Score. Next we’ll go through why they’re important and what you can learn from them.

  • Previous Night
  • Sleep Balance
  • Previous Day
  • Activity Balance
  • Body Temperature
  • Resting Heart Rate (RHR)
  • Recovery Index

In addition to calculating the Readiness Score, Oura also tracks your Heart Rate Variability, a readiness metric worth keeping an eye on.

Readiness view on the Oura app

See your readiness metrics in the Oura app

Previous Night

How well you slept the night before has a big impact on your Readiness Score. Good quality sleep is a must for physical and mental recovery – for your memory and learning capabilities, for example. Oura gives you a daily Sleep Score. A general rule of thumb is that it should be above 88% or at the high end of your normal range, if you’re planning to do something that calls for your maximum performance. Emphasis is on the ‘high end of your normal range’ because we’re all unique and sticking to a particular number isn’t advisable.

Sleep Balance

Readiness is about balance. The Sleep Balance contributor is based on a longer term view of your sleep patterns. Oura compares the past two weeks of your sleep duration to your long-term sleep history and the amount of sleep time recommended for people your age. It’s advised that for staying healthy and alert, adults typically need 7–9 hours of sleep every night.

Previous Day

Yesterday matters when we want to know how ready we are for today. Oura stays on track of your previous day’s load and guides you accordingly. If you have trained intensively, taking time for recovery pays off; that’s when you build your fitness. If you have rested well, your body and mind are readier to accept big challenges.

Activity Balance

The Activity Balance contributor is based on a five-day rolling window of your activity levels. Here again, balance is the key. For maximum performance, the aim is to stay adequately active: as close to your daily activity goals as possible. Staying in balance will boost your readiness and help you maintain high energy levels.

Body Temperature

Knowing the variations in your night-time body temperature helps you to detect early signs of impending sickness, a need to rest, and for women, the stages of menstrual cycle. Oura tracks and shows you the variations, so that you’ll keep on track of how recovered and ready you are for the day. Furthermore, recent studies advice female athletes to schedule the majority of their heavy intensity training to the first half of the menstrual cycle.

Resting Heart Rate

RHR, or resting heart rate, is a reliable and scientifically proven measurement for establishing overall sleep quality, recovery and health. Usually, a RHR on the lower side indicates good fitness, but don’t get too worried if your friend’s value is different from yours: RHR is highly personal and there are many factors that influence it. What you might want to concentrate on are changes compared to your own average, because an exceptionally high or low resting heart rate can be a sign that you need more recovery.  Oura shows your lowest and average RHR, as well as minute-by-minute resting heart rate graph.

Recovery Index

The timing of your lowest RHR is of significance, too. It tells you how balanced your body is in recovering from the previous day’s load and getting ready for tomorrow’s challenges. Recovery Index is one indicator of this balance: it shows how long it takes for your RHR to stabilize and reach its lowest point. An indicator of good readiness is if this happens earlier in the night (one rule of thumb is at least six hours prior to waking). For instance, eating a heavy meal, drinking alcohol, or exercising too close to bedtime can postpone the timing. They all speed up your metabolism and elevate your RHR, which in turn delay your recovery and increase your sleep need.

Heart Rate Variability

In addition to calculating the Readiness Score, Oura also tracks your Heart Rate Variability (HRV) throughout the night. What is HRV? Well, there’s a small time gap between your heartbeats, and this gap isn’t identical all the time. Heart Rate Variability indicates the variation in the time interval between heartbeats. Both researchers and practitioners consider HRV to be a good measure of your recovery, and therefore readiness status, as it can indicate stress and fatigue levels on your body. Generally speaking, when you’re fit, relaxed and recovered, your HRV is higher. When your body is recovering from e.g. strenuous exercise, your HRV is lower.

The HRV value given by Oura can range from anywhere below 20 to over 100 ms. But bear this in mind: HRV is extremely individual.

Oura calculates your night-time HRV from the rMSSD, a well-known HRV parameter that provides a good view on your Autonomic Nervous System activity. The Oura app shows your average HRV (from 5-minute samples measured during the whole night), and and your nightly HRV curve.

The HRV value given by Oura can range from anywhere below 20 to over 100 ms. But bear this in mind: HRV is extremely individual. Your minimum and maximum values depend on factors such as your age, hormone levels, circadian rhythm, lifestyle and overall health. So do not compare your values with anyone else but yourself!

If you’re interested in tracking your readiness and you don’t yet have the tools for it, have a look at the new Oura ring in the Oura Shop. If you have an Oura ring, have a look at our Readiness FAQ for more answers or dig deep into your data in the Oura Cloud.

National Winner Nordic Startup Awards 2017 Reddot Award 2018 Winner European Union - European Regional Development Fund leverage from the EU 2014-2020