Frequently Asked Questions
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Heart rate variability
Heart rate variability?
What is heart rate variability?
Heart rate variability (HRV) describes the way your heart beat varies - both at rest, and during exercise. Contrary to popular belief, the healthy heart does not beat like a metronome, but is constantly changing the time between beats in a rhythmic way. These changes are driven by the nervous system, trying to find the most efficient way for the body to operate. The fact that the nervous system makes itself visible through HRV makes the heart a wonderful barometer of how hard your body is trying to preserve its equilibrium. The higher the variance between beats the better, this shows your body is able to respond quickly to demands. Intensive or high volume exercise will stress & tire your body, and this stress is reflected as reduced HRV. Recovery, which is vital both for improved athletic performance and general good health, will cause your HRV to rise, letting you know that you are both getting fitter and avoiding staleness & sickness.
How can I benefit from using heart rate variability?
In two words: train smarter. It's hard for anyone (even experienced competitors sometimes) to judge whether they are under or over doing their training. Whilst the first leads to disappointing performance, the second can result in increased sick days through colds, persistent fatigue or worst case, substantial periods of layoff from exercise. By listening closely to your heart by measuring HRV, ithlete tells you when to train, how hard to train and when to rest. Once you are giving your body a training load it can cope with, your training effectiveness will improve, and you will not lose nearly as much time to overreaching related illness (such as coughs & colds) or unproductive sessions.
How does heart rate variability compare with morning pulse measurement?
Taking your morning pulse is a classic check for signs that your body is under stress & needs recovery, a morning pulse rate a few beats per minute higher than normal is a sign to go easy. However this is probably performed incorrectly by at least 50% of experienced runners & other athletes. The trouble is that there are multiple factors able to influence your heart rate and it is not that easy to perform the test accurately or to track when changes become significant enough to take action. You can think of the ithlete heart rate variability measurement as a more sensitive, up to date morning pulse test where the readings and calculations are all done with high precision and stored to develop personalised decision making criteria on when it is right for you to train, how hard to train, and when to rest.
Just remember when comparing the two that a higher HRV number is a good thing, indicating better rest & recovery, whereas a higher resting heart rate is bad and may indicate accumulated fatigue.
Heart rate variability research
There is an abundance of scientific research available for heart rate variability. We provide summaries of the most relevant and recent research on our blog.
Who uses heart rate variability?
HRV has been used in hospitals for many years, mostly to help very sick patients whose beats are very regular, with little variation. HRV has also been used by elite professional athletes across a range of sports for decades to help assess their training load and readiness for matches and competition. HRV is used extensively in sports science research to assess the body's adaptation to training by becoming fitter. HRV analysis was traditionally performed under coach supervision using specialised software that requires a sports science background and specific training. Systems were expensive and measurements complex.
ithlete is the revolutionary app making heart rate variability monitoring available to all, allowing the benefits of HRV training to be gained by anyone with an smartphone, iPad or iPod!
Who uses ithlete?
Users range across a wide spectrum of sports and abilities; from Premier League football clubs and Olympic athletes through personal trainers and weekend warriors to individuals who just want to keep fit and healthy. Whatever your level of fitness ithlete can help you optimise training and improve performance.
To hear what some of our current users think check out the range of case studies
What equipment do I need to get started?
To get started with ithlete you need;
- A compatible smartphone or tablet
- The ithlete app
- A Polar standard heart rate monitor & ithlete ECG receiver OR a Bluetooth Smart heart rate monitor
Which mobile devices are compatible with ithlete?
Requires iOS 4.3 and above i.e. iPhone 3GS, 4, 4S, 5 / iPod touch 3, 4, 5 / All models of iPad
- Samsung Galaxy S, S2, S3
- Samsung Galaxy Note
- Samsung Galaxy Nexus
- HTC Desire, Desire S, HD
- HTC Thunderbolt
- Motorola Droid Razr
- Motorola Droid Bionic
- HTC Evo 4G
- HTC G2
- HTC Rezound
- HTC Vision
- SEMC Xperia X10
- Asus Nexus 7
- … many other models! If you have tested ithlete on other Android devices please let us know so we can add them to this list.
We do not yet recommend using ithlete with Android based tablet devices such as the Samsung Galaxy or Nexus 7. We hope to correct this soon.
Some newer Samsung and HTC models previously required a modified receiver - the new model of ECG receiver we are selling is universal for use with all Android and iPhone devices listed above.
Which heart rate monitor (HRM) straps is ithlete compatible with?
Bluetooth Smart heart rate monitors (HRM)
The Cardiosport Blue is recommended for use with for use with compatible devices (such as iPhone 4S or 5, iPad 3 & iPod Touch 4). Although Bluetooth Smart is built in to the hardware of many new Android devices, it has not yet been enabled for app developers to access. We hope Google will allow this soon!
We have also tested the Polar H7 and Zephyr HxM Bluetooth Smart models, both of which work successfully.
Some other models of Bluetooth Smart chest strap, such as the Wahoo Blue™, do not currently support the RR part of the standard and cannot be used to measure HRV with ithlete.
Some of our users have reported that the Viiiiva 4iiii model doesn’t work with ithlete, however we have been assured by Viiiiva that the current firmware version of this strap has been thoroughly tested and delivers great results.
Analog heart rate monitor (HRM) straps
Here at ithlete we recommend using the Cardiosport heart rate monitor in order to ensure the best quality reading and an accurate HRV measurement. Although you can use your existing chest strap monitor who wants to search for and put on a sweaty strap in the morning? No, we prefer to keep a Cardiosport strap next to the bed for ithlete measurements.
If you do want to use your existing chest strap monitor, the ithlete ECG receiver is compatible with most makes and models which work with gym cardio equipment. Some tried and tested models proven to work include...
- Polar T31, T34, T61
- Polar T31 coded (incl Wearlink)
- Suunto Dual
- Nike analog chest transmitter belt
- Sigma Sport non coded
- Oregon Scientific analog
- Decathlon Geonaute HRM Chest belt
Many users contact us to ask whether the ithlete ECG receiver is compatible with Garmin ANT+ chest straps; unfortunately not at the present time. The Polar analog transmission standard has been proven in research to provide readings accurate enough to measure your heart rate variability. It is with this in mind the ithlete ECG receiver was designed to use this standard.
Getting stated with ithlete
Already checked out our ‘How to use ithlete’ Page but still have some questions?
Time of measurement
We recommend taking your daily ithlete measurement first thing in the morning for two reasons; primarily to allow you to make informed decisions regarding the days workouts and also to avoid the influence of variable external factors (such as life/work stress, caffeine etc.).
Some people like to do their measure as soon as they get out of bed, whilst others prefer to walk around, or do some light stretching as part of their morning routine, then do the measure.
Standing vs. supine measurement
First and foremost, consistent measurements are more important than position. This is because each position appears to provide important data regarding training status. Therefore, pick a position and stick to it 100% of the time for your measurements to be meaningful. Switching positions from day to day will provide skewed data and affect daily ithlete colour indications.
Most users can take their ithlete HRV measurement sitting down.
Extremely fit endurance athletes and individuals with low resting heart rates (<50bpm) are advised to measuring HRV in a standing position. HRV research studies have found that HRV is distorted when lying down in people with very low resting HR (50 and under). Standing (or even sitting) will raise this by a few bpm because your heart has to work a little more to pump blood uphill. However if you find this uncomfortable or would prefer to sit during measurements that is fine – just be consistent!
Establishing a baseline
To first establish your baseline we would recommend getting started with ithlete during a recovery/light training week if possible. However that is in a perfect world and we understand it is a lot to ask of fitness enthusiasts to take a week off! So ideally just avoid very intense workouts during that time. The baseline is a actually rolling average, so as you adapt and improve the average rises ensuring your change from baseline and daily training recommendations remain relevant to your current level of fitness.
As baseline continuously adjusts, it is not a problem longer term if you start in an overtrained state; it would still guide you back to health without affecting your long term baseline and training recommendations. If you did suspect you were overtrained, then rest is needed anyhow, and the direction of the change will tell you whether you were sympathetic overreached (HRV will increase) or parasympathetic overreached (HRV will decrease).
Interpreting ithlete results
The ithlete User Guide provides a comprehensive overview of how to get the most out of ithlete, and includes articles by experienced coaches and users.
|ithlete Guide to Training with HRVUnderstand more about over-training and training with heart rate variability.
Download the Guide
Each morning ithlete will provide you with a colour coded number (your ithlete HRV daily score). The colour refers to your change from baseline and recommended training.
- Green = Very good recovery, you are ready to train
- White = close to baseline, workout as normal
- Amber = Light (aerobic) exercise or active recovery
- Red = Rest
You will also see weekly and monthly change indications. This allows you to see whether your general trend is increasing (linked to increased health and performance) or decreasing (heading towards an overtrained state).
How do I use the export file?
All of your ithlete readings can be exported via Dropbox or to the email address of your choice. That could be a friend, coach, or yourself in order to include in your training log or just to keep a safe copy.
The file is in .csv (comma separated variable) format and can be imported into many spread sheet programs such as Excel, Numbers and Open Office. These programs will do some basic formatting for you when you open the file, and will put the Date, Time, HRV and resting HR into separate columns. The final column is made up of the Indicator letters that ithlete uses to make recommendations on your training for that day.
These are interpreted as follows:
W = White = Workout as normal
A = Amber = Light (aerobic) exercise
R = Red = Rest
G = Green = Good recovery
N = Not the first reading of the day = Not used in the ithlete chart
View the Dropbox Integration Guide
What is the ithlete ECG receiver’s operating range?
The working range of the receiver is set by the software and depends on which app is being used:
For ithlete HRV the operating range is quite short, typically 10-12" (250-300mm). This is deliberate so we can get the strongest signal to measure the precise position of each heartbeat, and also so that the phone display is visible to allow the user to follow the lung animation.
For Precision Pulse the operating range is longer, typically 31-36" (800-1000mm). This is typical for analog heart rate monitors that are sensitive to interference. Precision Pulse has an automatic gain control system to minimise interference when the receiver is close to the body, but you will notice the signal drops out temporarily as you move the phone away from the body quickly. It will re-establish after 2-3secs.
The range achieved does depend on the type & quality of the chest strap being used. The Cardiosport model we supply as well as the Polar T31 models offer the best range we have seen.
If you are having problems with range or interference and have a compatible device we would strongly recommend upgrading to the Cardiosport Bluetooth Smart heart rate monitor.
Having trouble with some aspect of using ithlete? Perhaps one of the headings below describes the problem and possible solutions. The ithlete Users Guide is also a great resource.
Connecting your Bluetooth Smart HRM strap
To connect your Bluetooth Smart HRM strap follow these simple steps…
- Put on your Bluetooth Smart HRM strap, ensuring the skin contacts are moistened
- Open the ithlete app
- Navigate to the ‘Edit’ screen from the bottom right of the app
- Switch Bluetooth Smart to ‘On’
- Select your strap from the pop-up list of detected straps within range
- Upon opening the app next time, ithlete will automatically detect previously paired Bluetooth Smart straps within range
Please note: Bluetooth Smart HRM straps can only pair with one app at any time. If you have previously used another app please disconnect before attempting to pair with ithlete.
Not picking up a heart rate signal
If the heart does not pulse after pressing Start and the two indicators at the top of the screen stay red the app is not receiving a heart rate signal from the chest strap. Things to check:
- The receiver (if using traditional HRM strap) is pushed all the way into the phone and is not blocked by a case or cover. It has a firm 'click' when seated correctly.
- The HRM chest strap is a compatible model
- Ensure that the skin contacts are moistened and that the strap is tight without being uncomfortable
- The ithlete logo on the receiver is facing forward and that the receiver is no more than 8-10" (25cm) from the centre of the chest strap
- Some android phone users experience difficulty using the older model of ECG receiver, if you are having problems try watching the video below.
Hr dropping out during measurement
If the 'Pulse' or 'Valid RR int' indicators at the top of the screen turn red more than once or twice during the measurement, it is likely that the chest strap is not tight enough, the skin contacts are not moist enough, or the chest strap (or its battery) is nearing the end of its useful life.
This quick video will help you ensure you are using the chest strap correctly.
Are you getting ithlete readings that are much higher or lower than you were expecting?
Understanding amber increases
In general, increases in HRV represent recovery, especially if the increase is back towards, or slightly above your baseline (the blue line). Slightly above represents super-compensation of course.
Occasionally you may experience an increase in daily ithlete HRV score with an amber training recommendation. The system is then detecting a parasympathetic level much higher than baseline. In strength, power and sports requiring explosive efforts, this kind of increase is often associated with temporary sympathetic exhaustion, so the parasympathetic branch of the body's regulation system is seen to dominate.
Decreasing HRV even after rest
Heart rate variability is a great measure of stress and not all stress is physical. Whilst you may be recovered from the physical stress placed upon your body from workouts have you considered cumulative stress? Cumulative stress is what HRV actually measures and is also affected by mental and chemical stress. So next time your HRV starts to decline but you feel ready for physical exercise you might want to think about your diet and life stressors.
Why don’t I get the same reading when I repeat the measurement?
If the HRV number decreases and / or the resting HR increases during multiple readings, then you are not relaxed enough. HRV is a sensitive measure of stress, whether physical or mental, and anxiety about the HRV reading will lower it. You need to think of your ithlete HRV measurement more like a blood pressure than an HR measurement (in fact heart rate variability and blood pressure are regulated by exactly the same parts of the nervous system). Many people have heard of 'white coat hypertension' - that's when your blood pressure is higher in the Doctor's office simply because you are anxious. That same anxiety or lack of relaxation will also lower your HRV.
The way you breathe will also affect the HRV reading (see below). Breathe in time with the lungs; focus on the flow of air in and out of your nose & mouth. Never force your breathing.
We strongly recommend doing one reading and not repeating without leaving a 5-10 minute break if you really think the first saved measurement was wrong. If you are disturbed during your first measurement simply select ‘Don’t Save’ and repeat the measurement.
Why does the way I breathe affect my ithlete readings?
Heart rate variability and breathing are intimately connected, and that is the reason we included the paced breathing of the lungs animation to provide consistency in the measurement. The chosen breathing rate is based on highly respected research into the effects of breathing rate on HRV; however some people feel it is too fast for them, especially if they are practised deep breathers. You can choose your own breathing rate if you prefer, but HRV is a sensitive measurement, so keep it consistent from one day to the next, and never take HRV readings when breathing irregularly.
The following quote is from Dr Liz Miller, a former neurosurgeon, psychologist & author (and ithlete user!):
“The emphasis is getting people to breathe right, which maximises HRV because breathing profoundly affects HRV - Heart Rate Variation is largely due to the changes that occur during breathing - breathe in - Heart Rate goes up - breathe out - Heart Rate goes down. These changes are healthy, normal and partly relate to the mechanics and partly to the autonomic (sympathetic and parasympathetic) nervous system. The greater the changes between breathing in and breathing out, the healthier and fitter your heart, lungs and autonomic system.
In other words heart rate variability measures the amount your heart rate changes from moment to moment. Most of this difference is due to breathing patterns.
Any change in mental state, even if you are an Indian meditation guru will change your pattern of breathing - the two are inextricably linked! Anxiety produces shallow fast breathing, calm produces slow deeper breathing. The slower and more consistently you breathe, the greater your HRV at any moment, up to a maximum that relates to your own personal fitness and gives you an ithlete number.
Inconsistent breathing, even slight, profoundly affects HRV. Although most people learn subliminally that to get their best reading, they need to follow the animation on the screen, and breathe in a slow and measured fashion, it is possible to mess with your HRV by fractionally altering your breathing. This will happen if you are anxious, tired or otherwise stressed.
From a user point of view - HRV needs to be a peaceful ritual. You sit and relax for a couple of minutes, watch the graphic on the screen and then when you are feeling calm, join in breathing with it and then when you are happy your breathing is nicely synchronised, switch on the device and measure your HRV.”
Watch our HRV App Video
"Supporting London 2012 Olympic athletes from other side of world. Text, phone, Kinesiocapture, ithlete r tools of the trade. (Twitter)"
Ken Vick, Performance Coach
"your device has been a real godsend after a severe bout of overtraining syndrome last year"
Sarah Ledbury, Triathlete
"I really like having the HRV number each morning to gauge my workouts from day-to-day rather than trying to follow a weekly schedule."
Jaacob Bowden, Professional Golfer, http://www.jaacobbowden.com
"great for confirming what I feel and forces me to make the right choice about training for that day"
Liz Yelling, Olympic Marathon Runner
|» See more Reviews|
Case Studies» See all Case Studies
Watch our Precision Pulse Video
|Cycling Weekly (UK) 10/06/2010|
|"ithlete has masses of uses and we can't help but feel a more complex version would increase the appeal even further."|
|Irish Independent Fit Magazine 10/2012|
|"Using ithlete to monitor stress is the best thing you can do to make your training safe and effective."|
|» See all Press Articles|