A large-scale analysis of longitudinal measurements acquired in free-living — Last year we published a research paper that was in the making for many years, looking at resting physiology (heart rate, heart rate variability) both between individuals or at the population level, with respect to age, sex, body mass index, and physical activity level and within individuals, with respect to…

There’s light at the end of the tunnel — This post is a case study about my personal data. I wasn’t blessed with much athletic talent, but I am really passionate about running and data science, which has motivated me to build HRV4Training, a platform to measure and interpret physiological data. Over the years, I did make a bit…

everything you need to know about Oura, Whoop, and Garmin when it comes to HRV measurements — More and more wearables have started capturing Heart Rate Variability (HRV) data overnight. Despite some inconsistencies over the past years, as of the end of 2022, Oura, Whoop, and Garmin all work in a very similar way when it comes to this type of overnight HRV measurement, which motivates this…

Guidelines and practical tips — Morning measurements of resting physiology (heart rate, heart rate variability), are arguably the most practical and effective way to capture our acute response to daily stressors as well as long-term or chronic changes in baseline physiology. In this blog, I cover simple guidelines and try to clear up some confusion…

Earlier today I was reviewing a journal paper looking at morning and night heart rate variability (HRV), a topic I have been thinking about a lot due to my work with HRV4Training and Oura. Reading Andrew Flatt’s tweet yesterday, I got thinking about this a bit more. In this blog…

Data quality and applications In this post, I look at the accuracy of the Whoop band version 4.0 in detecting RR intervals and cover a few potential applications of this technology. This blog is not about the Whoop’s night HRV data, which I only briefly discuss towards the end. The…

For feedback or comments, you can reach me on Twitter (@altini_marco) Technology for Heart Rate Variability (HRV) measurement at rest is getting better every day. From our own approach using the phone camera in HRV4Training (validated, and independently validated), to the Oura ring, Polar Vantage V2, Scosche Rhythm24, and Apple…

Research and practical insights — For feedback or comments, you can reach me on Twitter (@altini_marco) You’ve been preparing your race for several months and it’s finally time to taper. Training went really well and you are doing everything right: reducing volume, maintaining some intensity, paying attention to your diet and sleep. And yet, your…

What resting heart rate and HRV can tell you in the longer term — For feedback or comments, you can reach me on Twitter (@altini_marco) Heart rate variability (HRV) trends over long periods of time (e.g. from weeks to months) are one of the most interesting and complex aspects to analyze when it comes to resting physiology. …