Special Issue "Smartphones and Wearable Sensors for Monitoring Heart Rate and Heart Rate Variability"
Excited to have been invited by the Sensors scientific journal to set up a special issue on smartphones and wearable sensors for heart rate monitoring. Contributions ranging from technology development to applications relying on such data are welcome.
Please learn more about the special issue at the link below (or here). I am looking forward to reading your contributions
Heart Rate Variability (HRV) Biofeedback and Athletic Performance: Expected physiological, psychological and performance outcomes
In this last part of my introductory series on HRV Biofeedback, I will provide an overview of the main outcomes of HRV Biofeedback interventions, in terms of performance changes as well as physiological or psychological changes. I will first report on early explorations, then move towards higher-quality studies and finally cover recent attempts to investigate HRV Biofeedback interventions in more applied and practical settings.
In this video, we discuss:
In questa puntata per gli amici italiani, parliamo di:
- cos'è l'HRV
- come ho iniziato a studiarlo
- a chi può essere utile questo parametro
- come utilizzare i dati
- esperienza nel mondo delle startup
Grazie Manuel per l'invito
Human movement sciences thesis: Heart rate variability is representative of individual training adaptation to an altitude training camp in elite triathletes
I've discussed (virtually) my thesis at Vrije Universiteit Amsterdam and completed my Master's in Human Movement Sciences, specializing in high performance coaching. Abstract of my thesis below or at this link.
We will submit this work for publication, hence at this stage the full text is not available.
Objectives: To determine if changes in resting heart rate (HR) and heart rate variability (HRV) during the beginning (first 10 days) of a three-week training camp at altitude are representative of the athlete's training adaptation at the end of the training camp.
Methods: Four elite triathletes (2 male and 2 female), spent 23 days in Namibia at 1655 meters of altitude for two consecutive years in January 2019 and January 2020. Resting HR and HRV (the root mean square of successive RR intervals, or rMSSD) were measured daily upon wakening, while training data (GPS, heart rate) was acquired during cycling and running workouts. The athlete group was divided in responders and non-responders to the training camp at altitude based on the ratio between velocity and heart rate during aerobic running workouts of moderate duration. In particular, athletes whose velocity to heart rate ratio during workouts at week three was within the athlete's smallest worthwhile change (SWC) of pre-camp values, were considered responders. The difference in resting heart rate, rMSSD and the coefficient of variation of rMSSD (CV rMSSD) between the two weeks prior to the training camp and the beginning (first 10 days) of the training camp were computed as potential markers of future training adaptation.
Results: Resting HR was significantly more elevated during the beginning of the training camp for non-responders (N = 3, HR difference = +4.6 bpm) with respect to responders (N = 4, HR difference = +0.5 bpm, p = 0.023). The CV rMSSD also increased by a greater extent for non-responders (+10%) with respect to re-sponders (-3%, p = 0.015). The difference in rMSSD was lower during the first week of camp for non-responders (-10 ms) with respect to responders (+6 ms), but this difference was not significant (p = 0.336).
Conclusions: Athletes that responded positively to a three-week training camp at altitude showed a more favorable physiological response during the beginning of the training camp (smaller resting HR difference, lower CV rMSSD). This information can be used to further adjust training plans at the individual level.
Heart Rate Variability (HRV) guided training to improve performance: Latest publication using HRV4Training
In this study, the authors put to the test standard block periodization vs HRV-guided training, showing better results for the HRV-guided approach. Personally, I believe this paper is what I've been working for in the past decade.
It doesn't take much to understand that our capacity to handle stress is limited, and that stressors (training as well as lifestyle) can be better balanced by most of us. It is however far from straightforward to develop valid, reliable and easy to use instruments that can enable this process, to the point that new research and practical insights can be derived consistently by the use of such an instrument.
More of this please!
> The principle
HRV helps us to quantify individual responses to stress. The hypothesis for HRV-guided training is therefore that by providing the most appropriate training stimuli in a timely manner, when your body is ready to take it, positive adaptations will occur and you will be able to improve performance
> The protocol
The HRV4Training app was used to collect data first thing in the morning. When the HRV baseline fell outside the normal values for an athlete, training intensity changed from high-intensity training to low-intensity training or rest
Performance outcomes (VO2max, peak power output, ventilatory thresholds, and a 40-minute time trial) were all improved in the HRV-guided group, which also showed a better physiological profile (reduced CV HRV), highlighting a better response.
Learn more about the study, how you can use the same approach and monitor individual responses to stress, at this link
Improve self-regulation and better cope with stress using HRV4Biofeedback, the camera-based Heart Rate Variability (HRV) Biofeedback app
Heart Rate Variability (HRV) Biofeedback is a technique that can directly affect physiological and psychological factors through deep breathing exercises and is an ideal strategy to help us self-regulate and better cope with stressful situations
Practically speaking, HRV Biofeedback consists of providing an individual with real-time feedback on instantaneous heart rate and respiration changes while being instructed to breathe at low frequencies
You can learn more about the psychological and physiological benefits of deep breathing and HRV Biofeedback, at HRV4Biofeedback.com
HOW CAN I BENEFIT FROM BIOFEEDBACK?
Life can be demanding, from both a physical and psychological point of view
Our health and performance can be affected by how we are able to effectively cope with stressful situations and deal with anxiety, or in broader terms, our ability to emotionally self-regulate is key
The goal of HRV Biofeedback is to improve self-regulation, therefore impacting positively our health and performance
In this episode of the OCR Underground Show, we discuss what HRV is exactly, how you can use it in your training, and the best ways to measure it.
We also discuss some projects we've been involved with monitoring HRV during self isolation and its effect on the nervous system.
Enjoy and thank you Mike for having me!
Last week I had a chat with Lucas Rockwood, founder of Yogabody. It was a pleasure to catch up for a second chat about three years since our first episode together.
What You’ll Learn (link here):
Thanks Lucas, I hope things we'll get better soon in Barcelona as well. Take care!
Check out the latest episode on the Oxygen Addict triathlon podcast, featuring our work and a lot of practical tips on how to use HRV4Training and heart rate variability to make adjustments to your training
Dr. Marco Altini is the creator of the HRV4Training App. In this episode, we dive deep into heart rate variability, and why it might well be the most important training tool to getting the most out of your limited training time!
Thank you Rob for having me!
Special thanks to Rob Wallace for inviting me to speak to triathlon coaches in Australia about HRV and our work with HRV4Training. In the one hour webinar, I cover:
The webinar was recorded and is available at the link below. Enjoy.
In this series of posts, I discuss Heart Rate Variability (HRV) Biofeedback, and in particular:
While part Four of this guide is mainly focused on athletic performance, Parts One, Two, and Three are generic and cover aspects applicable to any other population in terms of the benefits of improved emotional self-regulation for health and performance.
Learn more at this link.
We have partnered with the Biomedical department of the University of Milan to provide free Heart Rate Variability apps in the context of a new study investigating the effect of home isolation on the cardiac autonomous nervous system.
Prolonged isolation studies during quarantines have focused mainly on the clinical effects of isolation, reporting emotional disorders, irritability, insomnia, poor concentration, deterioration of working capacity, stress symptoms and decision-making skills. The reduction in physical activity seems to contribute to the establishment of these dynamics.
The purpose of this project is instead to monitor the psycho-physiological impact of home isolation that is occurring in Italy as a consequence of the general lockdown aimed at containing the pandemic spread of covid-19.
Psychological monitoring will focus, through the remote administration of validated questionnaires, on sleep disorders (Pittsburg Sleep Quality, PSQI), affective and emotional states (UCLA Loneliness scale, Profile of Mood States, POMS), on trait and state anxiety (State-Trait anxiety Inventory, STAI) and on the level of physical activity (International Physical Activity Questionaire, IPAQ).
Physiological monitoring will evaluate the modulation of heart rate by the autonomic nervous system (HRV), as measured using the Camera HRV app, so that questionnaires data and objective physiological stress levels can both be analyzed.
I would like to thank professor Giampiero Merati of the University of Milan for involving us in this project and I hope our tools we'll be helpful to gather objective data on ANS activity. Our own data tells quite a clear story, as we still struggle to adapt to the new normal.
Free camera-based heart rate app to support self-awareness as well as data donation projects in the context of covid-19
In the past weeks, we have developed a free (and private) camera-based heart rate app to support self-awareness as well as data donation projects in the context of the current covid-19 pandemic.
Since the start of the outbreak, I've been approached by many doctors and scientists that have been looking into simple and cost-effective methods to identify and manage individuals that might require additional care. Physiological measurements (for example resting heart rate, HRV or temperature), are all great candidates as these parameters have shown a consistent response to infections (you can find some data here).
At the same time, many research institutions and governments are starting data donation initiatives to track covid-19 symptoms, at a much larger scale. One of the main examples of this approach is the corona-datenspende app launched by the Robert Koch Institute (the National Health Institute in Germany), which also aims at integrating (anonymized) objective physiological data collected with wearables such as Fitbit and Garmin smart watches.
I was recently made aware of the project by my former PhD supervisor, professor Oliver Amft, who is actively involved with the Robert Koch Institute and also familiar with our work on camera-based measurements. Needless to say, a free camera-based heart rate monitoring app could empower people from a self-awareness point of view, as well as give them the opportunity to contribute to these project. Hence, in the past week we have developed Camera Heart Rate, 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.
The app relies on HRV4Training's technology and is currently available on iOS in selected areas. Please read below to learn more.
Why resting heart rate?
Something as simple as measuring resting heart rate, is a very useful tool to capture changes in physiology due to our body fighting various forms of stress, including infections . In particular, infections tend to show up in the data as increased heart rate (and reductions in HRV). You have probably noticed these changes in the past if you were ever sick while also collecting data longitudinally. This can happen a short time before we actually realize that something is going on (say a day or two in my experience).
Already years ago, Michael Snyder at Stanford University ran studies in free-living using commercially available sensors and found quite striking relationships between heart rate and infection (if you are into papers, I highly recommend this one ). We have also shown reductions in HRV and increases in HR with respect to self annotated sick days, in this blog post.
Infections or getting sick in general, are one of the few conditions in which I would almost consider heart rate superior to HRV (or at least equal). Why is that? First, heart rate does not change much on a day to day basis, and is less sensitive than HRV to changes in physiological stress due to for example training, lifestyle stress, etc. (we have previously quantified these differences, with heart rate changing only 0.5–1% in response to hard training sessions for example, and HRV changing on average 5–8%, full paper here ). Secondly, heart rate changes to a much greater extent when facing an infection. Hence heart rate can be a simpler marker to look at, less affected by other stressors, and we could look at changes in heart rate to make sure things are staying within a normal range (based on your historical data).
Privacy by design
The Camera Heart Rate app does not include any backend server and stores data only locally on the users' phone. The only data sharing option in the app is via Health, which allows users of the app to push heart rate data to Health after the measurement.
Once you have linked the Camera Heart Rate app to Health, the corona-datenspende (or another service that you use) can read the data from Health for further processing. Camera Heart Rate behaves simply as a heart rate monitor, and does not provide any interpretation or diagnostic.
Camera Heart Rate is powered by HRV4Training, the first validated camera-based heart rate variability (HRV) app. You can learn more about resting heart rate and measurement guidelines at the Camera Heart Rate FAQ page.
Camera Heart Rate is currently available on iOS and supports English, Italian and German. We have released the app only in selected areas, but if you are interested in potentially using it also for your initiative, please feel free to reach out.
 Buchan, C. A., Bravi, A., & Seely, A. J. (2012). Variability analysis and the diagnosis, management, and treatment of sepsis. Current infectious disease reports, 14(5), 512–521.
 Li, X., Dunn, J., Salins, D., Zhou, G., Zhou, W., Rose, S. M. S. F., … & Sonecha, R. (2017). Digital health: tracking physiomes and activity using wearable biosensors reveals useful health-related information. PLoS biology, 15(1), e2001402.
 Altini, M., & Amft, O. (2016, August). Hrv4training: Large-scale longitudinal training load analysis in unconstrained free-living settings using a smartphone application. In 2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) (pp. 2610–2613). IEEE.
Better tools to help you keeping track of physiological changes in response to infections and sickness
With the ongoing global pandemic, the medical community has been looking into alternatives that can help identifying and managing individuals that might require additional care, which brought a renewed interest into wearables or in general in tools that can provide physiological measurements. Heart rate, HRV, temperature, are all great candidates as these parameters have shown a consistent response to infections.
In this context, in the past few weeks we have started a few collaborations with research institutions in Italy and Germany, providing the technology required to further investigate the relationship between (among other parameters), resting physiology and COVID-19 infections.
However, as a user of our system, you might want to know what to look at as a potential indicator of infection or sickness based on our current knowledge and published research.
In this post, I cover the basics of heart rate in the context of infections, and show a new feature we have built in HRV4Training Pro to help you identify more easily periods in which heart rate is abnormal, and therefore might require more attention.
I hope you'll find the material and new feature useful. Full post at this link.
Special thanks to Pro triathlete Scott Bayvel for inviting me for a chat on his YouTube channel. In the video, we cover the following:
Link here. Enjoy
You can find the episode here.
HRV4Training founder Marco Altini is on the show this week to explain heart rate variability (HRV) and how monitoring this metric can be used to guide endurance training.
Learn more about HRV4Training or Marco at their respective websites and follow them on Instagram and Facebook.
Read part 1 of Marco's guide to HRV-guided training on Medium. Then use the links in the article to access parts 2 and 3.
Grazie mille Omar e Bikeitalia per questa intervista su HRV4Training e la variabilità cardiaca
Come si misura?
Quali sono i dati che dobbiamo considerare per monitorare il nostro allenamento?
Come gestire al meglio lo stress dell’allenamento?