Recovery
HRV, without the jargon.
Heart rate variability sounds technical, but the idea is simple — and the most useful way to read it is against yourself.
By Mana4 min read
HRV is the natural variation between heartbeats. There’s no universal good number — compare it with your own baseline, and look at averages rather than single days.
A healthy heart is not a metronome
Your heart doesn’t beat at perfectly even intervals. The time between one beat and the next keeps shifting by small amounts, and heart rate variability — HRV — is the measure of that variation in the intervals between consecutive heartbeats.
That variability is a feature, not a fault. As one widely cited review puts it, a healthy heart is not a metronome: its constantly changing rhythm is what lets the cardiovascular system adjust quickly to physical and psychological challenges.[1]
There’s no universal “good” number
HRV can be measured in several ways, and the standards for doing so were first set out by a European and North American task force in 1996. Different methods and recording lengths produce different values, so numbers from different devices or apps often can’t be compared directly.
Context matters too. Baseline HRV varies with age and sex, and the same review cautions that norms for 24-hour, short and ultra-short recordings aren’t interchangeable. That’s why comparing your HRV with someone else’s tells you very little — comparing it with your own last few weeks tells you a lot more.[2][1]
HRV · 7-day average
58ms
Your baseline, not a target
Look at the average, not the morning
HRV is often used to see how well someone is adapting to training — but a review of research in elite endurance athletes found the picture is not simple. In that group, both rises and falls in HRV have been linked with poor adaptation, and day-to-day values are noisy.
The authors’ suggestions for day-to-day monitoring include using appropriate averaging techniques rather than reacting to single readings. For most of us, the takeaway is the same: watch the rolling average, and treat one unusual morning as one unusual morning.[3]
How Mana uses it
Mana measures HRV overnight, when you’re still and conditions are most alike from night to night. It builds your personal baseline over the first weeks, then shows how you’re tracking against it — as a trend you can glance at, not a score to chase.
It’s a way to notice patterns: how a hard week, a late night or a few good ones show up in your body. It isn’t a diagnosis, and a low reading on its own isn’t a reason to worry.
References
The sources behind the figures in this article. Interpretation and advice are our own.
- 1Shaffer F, Ginsberg JP. An Overview of Heart Rate Variability Metrics and Norms. Frontiers in Public Health, 2017; 5: 258. Read source
- 2Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Heart rate variability: standards of measurement, physiological interpretation and clinical use. Circulation, 1996; 93(5): 1043–1065. Read source
- 3Plews DJ, Laursen PB, Stanley J, Kilding AE, Buchheit M. Training Adaptation and Heart Rate Variability in Elite Endurance Athletes: Opening the Door to Effective Monitoring. Sports Medicine, 2013; 43(9): 773–781. Read source
General information, not medical advice. Mana is in development and isn’t intended to diagnose, treat or prevent any condition. If you’re concerned about your health, talk to a doctor.
