Frequently Asked Questions

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You can also send us questions and comments from within the app, the Team Dashboard, or on the contact form here.

  • Nothing on this page or site is to be considered medical advice – see Disclaimer for more info.

Q: How much does the Elite HRV app cost?

The Elite HRV app is free for iOS and Android! You can get the app here for iOS or Android.

Q: Where can I view HRV trends and other data?

All data is collected from the Elite HRV app on Android or iOS. It is then securely synced to the user’s private account in the cloud. If the user is connected to a Team, then the data automatically syncs to the Team Web Dashboard as well.

Certain trends (such as Daily Readiness, Heart Rate Variability and Heart Rate) are viewable directly from your preferred phone or tablet. More advanced trends (such as Coefficient of Variation, Sleep, Exercise) can be found on the web dashboard (link). The web dashboard is currently geared towards organizations and teams, but there is nothing stopping an individual from creating a personal team to make use of the web dashboard. A personal version of the web analysis dashboard is in the works.

Currently data can be exported from both the app and the web dashboard. Data exported from the app comes in raw R-R interval form and is sent to the email address associated with your app account. Data exported from the web dashboard is in the processed and calculated form and can be saved directly to your computer.

Q: What devices are compatible with the Elite HRV app?

(See this dedicated page for a full breakdown of compatible devices)

Compatible Phones, Tablets, and Smart Devices

The Elite HRV app can be found on both Google Play and the App Store. It is compatible with the following devices:


  • iPhone 6 and newer
  • iPad 4, Air 2, Mini 3 and newer


Compatible Heart Rate Monitors

To accurately measure Heart Rate Variability and transmit it to your compatible phone or tablet the heart rate monitor must have: 1.) Bluetooth 4.0 (also called Smart or LE), 2.) Accurate R-R Interval Recording (also called inter-beat intervals). Here is a list of Elite HRV-compatible heart rate monitors:

(See this dedicated page for a full breakdown of compatible devices)

Q: How long can I take an HRV reading?

Due to heavy server demand, we cannot currently process readings longer than 1 hour. Readings longer than 30 minutes may take several hours to process.


Q: Why can’t I use my wrist HR monitor or LED/pulse oximetry monitors like Fitbit?

Unfortunately, at this time the available wrist band monitors, watches, and finger sensors that use Pulse Oximetry or LED to detect heart rate do not accurately measure (or do not support) R-R intervals. R-R intervals are the exact time measurements between each heart beat that are needed for truly accurate HRV calculations. Due to the limitations of those hardware devices, we do not recommend them for reliable HRV readings.

These devices are fine for just getting your basic heart rate though!

These devices include the Fitbit Charge HR, Mio wrist devices, Polar wrist devices, Apple Watch, etc. We hope the hardware will advance sometime soon and provide accurate R-R intervals (We know they are very convenient!). In the meantime, the best option is to invest in a chest strap heart rate monitor. For convenience, here is a link to our current recommended chest strap:

Q: How far away from the app can I go during my workout or other activities?

The answer to this varies based on your hardware (and has almost nothing to do with the app). That being said, the Elite HRV app is designed to remain connected as long as you are within signal range (even if some heart beats are dropped due to distance). If you go completely out of connection range you may lose the connection entirely and need to restart the reading.

Our testing:

We have run tests at various distances and found the most accuracy and consistency within 15 feet. Outside of that range intermittent skipping of beats increases with distance – more details on testing below:

Heart Rate Monitor: Polar H7

Recommended – Under 15 feet away – consistent signal for short-term sampling Generally Acceptable (not for extended periods of time) – 15 to 30 feet away – intermittent loss of heart beats (R-Rs) Not Recommended – 35+ feet – consistent loss of R-Rs Notes: This was tested indoors with other electronic equipment in the near vicinity. Results may vary by receiving device, heart rate device, in outdoor open areas or depending on your equipment arrangements indoors.

Q: What is Heart Rate Variability?

Basic Heart Rate Variability (HRV) is the measured changes of the time intervals between successive heart beats. Unlike Heart Rate (HR) that averages the number of heart beats per minute, HRV looks much closer at the small fluctuations of the heart that occur in response to internal and external events.

Learn more about HRV and how it ties to your Autonomic Nervous System:

Q: How is Heart Rate Variability useful?

Knowledge is power.  By applying the appropriate research-backed calculations to Heart Rate Variabililty (Elite HRV does that for you), you can better understand your nervous systems, cardiovascular systems, and respiratory systems in response to life’s stressors.

By incorporating your HRV insights, you have a powerful tool to help optimize training, manage stress and improve health.

Q: Will the app show me my ability to handle stress or exercise each day?

Yes, each day that you take a Morning Readiness reading, you get a Colored Indicator, Autonomic Balance Gauge, and Morning Readiness Score that give you insight into your stress and recovery patterns.

Q: Can I use Elite HRV to 'train' my heart and nervous system?

Elite HRV has built in breathing guides that allows you to use your respiratory system to gain control over your cardiovascular system and nervous system and track the effects. However, it does not automatically guide you towards a state of “coherence.”

Q: Why is it important to measure HRV (Morning Readiness) in the morning instead of other times throughout the day?

The best way to determine your individual heart rate variability and thus nervous system activity is to take a short (1-5 min.) reading each day. Ideally you want the reading to happen at the same time, in the same way, so as to eliminate as many affecting variables as possible.

Throughout the day many factors can affect HRV. Internal processes like circadian rhythm and hormonal fluctuations cause it to slowly rise and fall over 24 hours. Also whatever you were doing before taking a reading has a very strong impact on the reading. Mental, physical and emotional experiences all affect HRV.

This is why we recommend taking the reading each morning. When you have just awoken you haven’t had the chance to experience the stresses of work, school, or the day. Your circadian rhythm and hormonal patterns should be consistent at that time as they were the previous day. We also recommend that you breath naturally for the Morning Readiness and take the reading in the same body position each time.

By calculating your baseline first thing each morning, you can eliminate a lot of variables and highlight the patterns that matter most. This allows you to cut through the “noise” and get insights about how recovered you are and how ready you are to tackle the day’s challenges.

Q: How do you calculate the HRV score?

Our HRV score process is broken down as follows:

  • We capture the R-R intervals via the chest strap heart rate monitor.
  • We apply the RMSSD calculation. Root Mean Square of Successive Differences (RMSSD) is the industry standard, time domain measurement for detecting Autonomic Nervous System activity in short-term durations (5 minutes or less).
  • A natural log (ln) is applied to RMSSD. Since RMSSD behaves logarithmically, it is difficult to conceptualize the magnitude of changes as it rises and falls. Therefore, it is common practice in the application of RMSSD to apply a natural log to produce a number that behaves in a more linearly distributed fashion.
  • The ln(RMSSD) is expanded to generate a useful 0 to 100 score. The ln(RMSSD) value typically ranges from 0 to 6.5. Using over 1,000,000 readings from our database, we have been able to sift out anomalous readings and create a much more accurate scale where everyone fits in a 0 to 100 range.
Q: What is a good HRV score?

Heart rate variability is highly based on individual circumstances. Everything from your mindset to air quality to age and exercise patterns can affect HRV. This is why we emphasize the personal trends and improvement over comparing yourself to others.

That being said, where do you stack up?

  • The average HRV score is 59.3 for Elite HRV users
  • This post covers values for your age, gender and the Elite HRV population breakdown:

A higher HRV is correlated with younger biological age and better aerobic fitness. We have a lot of young athletes as users, and they are setting the bar high! Remember the key to improvement is acute stress (training) followed by adequate recovery.

Scoring really low on any given day is usually nothing to worry about. It is your average over time that matters the most. Working towards improving your average HRV over time is a good and achievable goal.

Q: What are HRV score, RMSSD, ln(RMSSD), SDNN, NN50, and PNN50?

Our HRV score is calculated from the RMSSD and represents the strength of your Autonomic Nervous System at a given time. The other numbers provided are for reference for those interested in in more detailed analysis of their HRV data.

Here’s a quick run down of what they mean (NN or R-R intervals means the time between two successive heart beats):

RMSSD: Root mean square of the successive differences – used for a good snapshot of the Autonomic Nervous System and is the basis of our “HRV Score”

  • RMSSD is strongly backed by research and is considered the most relevant and accurate measure of Autonomic Nervous System activity over the short-term. Here are a few studies referencing its use:
  • More research about the use of RMSSD can usually be found on PubMed, ScienceDirect or other research libraries.

ln(RMSSD): A natural log is applied to the RMSSD in order to distribute the numbers in an easier to understand range

SDNN: Standard deviation of the NN (R-R) intervals

NN50: The number of pairs of successive NN (R-R) intervals that differ by more than 50 ms

PNN50: The proportion of NN50 divided by the total number of NN (R-R) intervals

Q: What do the Green, Yellow, and Red indicators mean on the Morning Readiness reading analysis?

Grey: You see this indicator type on your first Morning Readiness reading (or if you haven’t taken a MR reading in a while). The grey indicator with a score of n/a shows that you need to establish a baseline of a few days to compare to before you can start receiving Morning Readiness scores, indicators, and recommendations.

Green: indicates that compared to your own personal trends, you should be able to handle more stress today. This often includes being able to:

  • Exercise a little harder than normal
  • Tackle a few more items on your to-do list
  • Think a little more clearly at work or school
  • Have reduced systemic inflammation

Yellow (Sympathetic): indicates the body is under a bit more stress than usual. Consider lighter exercise and reducing stressful activity unless you have restful days coming up or if over doing it is not a concern.

Yellow (Parasympathetic): indicates the body’s recovery systems are working overtime to recover from a large or accumulated stress. This state is correlated with over reaching in training or over-active parasympathetic (recovery) systems.

Red (sympathetic): indicates the body is experiencing deeper levels of stress or fatigue. To avoid over training or over stressing it is highly recommended to prioritize rest.

Red (parasympathetic): indicates a deeper level of recovery activity in response to accumulated stress. The body is likely reaching an over trained state. It is strongly recommended to prioritize light active recovery.

Q: How does my HRV score determine Readiness?

As you take readings over time, the app establishes an individual baseline for you. The baseline is determined by the average HRV over the past 10 days of Morning Readiness readings.

When you take a new Morning Readiness reading, the app compares it to your baseline to determine if you are experiencing more stress, more recovery or are fairly similar to your baseline. (Important emphasis: The determination is relative to your own individual baseline!)

The app adjusts the sensitivity of the readiness gauge based on your baseline trends as well. If you are quite stable (i.e. only change a few HRV points from day to day), then a small change in HRV can register as a large change in readiness. Conversely, if you are fairly variable (large HRV score differences from day to day), then another moderately large swing in HRV score may possibly not affect readiness if it is within your normal bounds.

Q: Do you want to always get a Green indicator?

Green indicators are definitely good, but you may not want to get them all the time. Here are a few scenarios to consider:

If you are constantly stressed out mentally, emotionally or physically (over training) then you want to strive for Green as often as possible.

If your stress levels are under control and improving athletic training, exercise or movement is your goal, then you want to at least dip into the yellow 1-2 times a week to ensure you are stimulating your body adequately. If you are training for sports or more advanced movement/exercise then you may want to push it more often.

Remember: Stress causes adaptation. The right amount and type of stress (paired with adequate recovery) produces improvement and the wrong amount and type of stress can cause breakdown.

Q: Is a higher HRV always 'better'?

A higher HRV is generally a good thing, but there are exceptions which the app picks up on. You want your HRV to gradually increase over time (weeks, months, years). If you have taken a few Morning Readiness readings, you know that your HRV can go up and down slightly from day to day. This is normal and generally healthy.

Most folks understand that if your HRV drops a significant amount, it is indicating that you are likely experiencing abnormal amounts of stress (Sympathetic NS activity). It is then recommended to prioritize rest and recovery for optimal long-term results. However, it is less intuitive that the same can be said if your HRV rises a significant amount in a short period of time. If your HRV rises abnormally high (above a certain standard deviation) within a day or a few days, the app indicates with a yellow or red that you are likely experiencing abnormal amounts of recovery (Parasympathetic NS activity). This is often in response to accumulated amounts of stress.

Here are a few scenarios resulting in a high HRV score paired with a yellow or red readiness indicator:

  • Over training – Over reaching and over training can occur when you repeatedly experience a level of stress that your body can’t recover from. This often registers as decreasing HRV over the course of a few days, followed by a sharp increase in HRV suddenly one day. This happens because at a certain point, your body reaches a threshold where it has to stop prioritizing the fight or flight stress response, and goes into a deep recovery.
  • Mild sickness
  • Change in exercise routine
  • Change in sleep patterns

It is important for your body to go into deep recovery mode if it needs it. If you interrupt this process, you pose the risk of over training and/or not recovering fully from whatever stress your body is recovering from. This can have negative impacts on training improvements and longer term health.

One way Elite HRV tries to help you better understand your HRV scores in relation to your Autonomic Nervous System status is through our Autonomic Balance Gauge, Readiness Color Indicator, and Readiness Score. These additional readiness indicators increase clarity of what the HRV score means.

Q: How are HRV and blood pressure related?

Baroreceptors, which are the body’s natural blood pressure sensors located in the aortic arch and internal carotid arteries, contribute to heart rate variability. When you inhale, heart rate increases. Blood pressure rises about 5 seconds later. Baroreceptors detect this rise in blood pressure, which leads the system to automatically relax the blood vessel and fire more rapidly. When you exhale, heart rate decreases. Blood pressure falls about 5 seconds later. (Gevirtz & Lehrer, 2003; Lehrer & Vaschillo, 2008).

In our current library, we do not have any research that indicates certain HRV scores correlate with certain blood pressure levels, but we will keep an eye out for it and let you know if we find reliable research.

Q: Why are the HRV calculation results different than other HRV apps or systems?

Research standardized calculations such as RMSSD can still appear slightly different between systems. This could be due to differences in hardware (heart rate monitors, etc.). But it is usually due to differences in the way misreads and signal noise are handled. On the software side we calculate out misreads and signal noise as best as possible. Each system has their own method for calculating these misreads out (and some systems don’t even do this). This could potentially cause the same inputs and calculations to produce different final results. To minimize the possibility of misreads from your heart rate monitor please ensure the following:

  1. Thoroughly moisten the chest strap
  2. Tighten or loosen the strap to ensure it does not move across the skin during the reading
  3. Make sure the battery in the strap is not low
Q: Why do back to back readings sometimes produce different results?

As you have learned in our free guide, many factors affect Heart Rate Variability. The following answer assumes that you are taking readings back to back in a resting position (such as Morning Readiness readings).

The most relevant factors for differing back to back readings include structural stressors, breathing patterns and mental/emotional state. Let’s break this down.

Structural Stressors

Depending on the position you take your reading in, your body goes through phases of structural comfort and discomfort (sometimes cyclically as you make small subconscious shifts) in holding that same position. Think of this in terms of doing an isometric exercise such as holding a plank. The first 10 seconds may seem easy, but the last 10 seconds are quite stressful, and occasionally throughout you may shift your weight for some temporary relief. If you’ve ever looked at heart rate from the beginning of a plank to the end, you will see quite a difference in most cases.

Knowing this, the longer you stay in a position the more structurally stressful it can be and it can cause changes in subsequent back to back HRV readings. In other words, if you sit for 2.5 minutes it is much different than sitting for 7-8 minutes (the span of 3 Morning Readiness readings). This particular variable is less relevant in a comfortable lying position, in which case the opposite may occur – one may get more comfortable as the position is maintained.

Mental and Emotional State

Why does heart rate elevate when one gets on stage for a public speaking engagement? Our mental and emotional states can have a profound impact on our physiology at any given moment.

Regarding to back-to-back readings: Your expectations of different results, potential boredom, annoyance or excitement can all affect the outcome in addition to the other variables. In our experience, these particular changes (like boredom and annoyance) start occurring a little after the initial 2 minute mark in most people.

This is one of the reasons for the 2.5 minute Morning Readiness length as well as why subsequent readings in the same position can get increasingly affected by mental and emotional state.

Breathing Patterns

Breathing patterns have a large effect on HRV. You might have guessed at this point that breathing patterns change over time.

Breathing patterns are regulated by your body’s needs automatically unless conscious control is asserted. Two large influences on breathing patterns in a static resting position are structural stress over time and mental/emotional state.

In general the more calm, comfortable and parasympathetic you are, the longer and deeper your exhaling is. As you get more excited or uncomfortable, typically breath becomes more shallow – especially on the exhale. A great test you can perform to see these effects are to take a 1 minute reading just looking out a window and breathing freely – then immediately take another reading in the same position but following the guided breathing circle in the app at a comfortably slow pace.

So Many Factors, How Can It Be Reliable?

As you can see, in a resting position back to back readings can vary quite widely. This is the reason that we look at trends over time (days, weeks, months) and we focus on repeatable methods for measuring Morning Readiness readings.

In a series of back to back readings, the first reading is always the most relevant. It is the most comparable to the first reading on other mornings, and it eliminates as many of the factors listed above (or at least ensures that they are as comparable as possible).


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