THE ULTIMATE GUIDE TO HEART RATE VARIABILITY ​​

I've put together a series of posts that cover many aspects of HRV measurement, data interpretation as well as plenty of examples that you can look at to better understand how to make use of the data, and how HRV relates to training and lifestyle stressors.

​Check them out at these links:

Apps

Since 2012, I've been developing mobile apps using the phone's sensors to provide unique insights on the user's physiological status (such as heart rate and heart rate variability) without the need for external hardware. I have also helped a few companies developing similar technologies. You can find out more in my blog. These are the apps I'm currently supporting, even though most of my efforts are currently dedicated to HRV4Training.

HRV4Training

HRV4Training is first scientifically validated Heart Rate Variability (HRV) app. HRV4Training provides HRV based insights to help you quantify stress, better balance training and lifestyle, and improve performance. The app does not require a heart rate monitor, since it can accurately assess your HRV using the phone's camera. HRV4Training also works with Apple Watch, the Oura ring and Bluetooth sensors. More info here. I am also curating another blog on HRV4Training.com, covering technology, sport, physiology and data. 

Camera Heart Rate Variability

Camera Heart Rate Variability lets you record, plot and export time and frequency domain Heart Rate Variability Features (as well as heart rate and RR intervals), without requiring any heart rate monitor. Details on the implementation here.

HEART RATE VARIABILITY LOGGER

Heart Rate Variability Logger is an application that lets you record, plot and export time (AVNN, SDNN, rMSSD, pNN50) and frequency (LF,HF,LFHF) domain Heart Rate Variability Features. HRV Logger requires a bluetooth low energy (or BLE/SMART bluetooth) heart rate sensor. More info here.
I get quite a few emails asking "which app should you use", so here is a brief description.
  • Go for HRV4Training in case you are interested in a simple daily HRV measurement that quantifies physiological stress. The app adds a layer of interpretation and provides a daily advice, as well as many insights on longer term trends, custom correlations, etc. as you will be able to provide additional contextual information on not only training, but also lifestyle, and many other parameters. ​In general, I would advise everyone to use HRV4Training since it is by far the most complete product, and even if you are not much into training, it provides a good framework that is very helpful to analyze your physiological data with respect to other variables (in terms of consistency, measurement routine, tags or additional annotations you can correlate with physiological data). HRV4Training also provides levels of abstraction and interpretation of your daily scores with respect to your own baseline which make it easier to use it with respect to, e.g. Camera HRV which provides raw data information. You can find out more here and see many case studies here.
  • Go for HRV Logger (requires a Bluetooth heart rate monitor) or Camera HRV (camera-based, iPhone 5 or later) if you are familiar with HRV and more interested in experimenting or running studies collecting HRV data. These apps provide no interpretation but let you measure multiple times per day and export all the data, RR intervals included. 

Other projects

HRV4Training Pro: Web platform

HRV4Training Pro is the ultimate platform for individuals and teams that want to learn more about how their body is responding to different stressors associated to training and / or lifestyle. You can learn more here and here.

Strava: Relative effort

I have helped Strava developing their current Relative Effort, a metric used to quantify training effort, combining intensity and duration. You can read Strava's official launch blog post here as well as an interview I gave here. 

CAMERA HEART RATE

Camera Heart Rate is a free app that can be used to measure resting heart rate, and can share data only via the Health app, so that each user is in total control of their data and privacy. Learn more here.

bloomlife

At Bloomlife I was mainly taking care of data science activities. However, I had also developed an app that implemented part of my work around preterm birth risk assessment and prediction, using open data provided by the CDC. You can read more about our approach on another post I wrote on Medium.

The app uses twenty parameters to feed a Bayesian model and determine preterm birth risk. It is free and can be used by expecting mothers as well as by clinicians. For expecting mothers, the app provides awareness and perspective with respect to people with similar characteristics. On the other hand, by tuning the different parameters, clinicians can use the app to dynamically explore the dataset, therefore understanding the impact of different parameters without the need for downloading the dataset and further statistical analysis.

37

37 estimates your risk of preterm delivery, gestational diabetes and gestational hypertension based on your characteristics. Your risk factor is computed based on more than 3 million deliveries registered in the United States between 2012 and 2014 by the Center for Disease Control and Prevention. The app is no longer available.