The rise of technical gadgets now allows us to measure and track more personal data than ever before. Previously, the major contraption we used at home to monitor health was a simple scale; of course, weight is only one measurement of health, and now you can keep tabs on heart rate, blood pressure, number of daily steps, caloric intake, and more using devices like Fitbits and Apple Watches in conjunction with health apps.
However, there’s a popular new data marker in town: HRV. Many people—ranging from health professionals and competitive athletes to researchers and physiologists—have started looking at HRV as a key indicator for better sleep, stronger recovery, and overall health.
In today’s post, we’ll first define HRV, then delve into why it’s important, how to measure it, and how to use the data to your advantage.
What Is Heart Rate Variability (HRV)?
HRV stands for Heart Rate Variability, which is a measurement, in milliseconds, of the variations in time between each heartbeat. This variation or irregularity—which is perfectly normal, even for a healthy heart—is governed by a section of your nervous system known as the autonomic nervous system (ANS), which has an impact on your breathing, blood pressure, and digestion in addition to your heart rate. The ANS is important because it consists of two parts: the sympathetic system (your fight-or-flight response) and the parasympathetic nervous system (rest-and-digest), which work to maintain a delicate balance.Ultimately our ANS receives signals from the hypothalamus—which is constantly processing data—in your brain to either stimulate or relax various functions within your body. These responses can be negative or positive; your hypothalamus will react to a wildly stressful day at work or an awful night’s sleep, or to the revelation of the promotion you’ve been wanting or other good news. So, as you can imagine, prolonged bouts of stress, a poor diet, a failure to exercise, and even solitude can knock that balance out of whack, causing your fight-or-flight response to run rampant.
Why Is HRV So Important?
So if you followed that quick trip through those parts of your nervous system, then this will make more sense: HRV can help you determine if you’re experiencing the ANS imbalance we referenced. Here’s a simple breakdown:
- Lower variation between heartbeats = fight-or-flight response
- Higher variation between heartbeats = rest-and-digest response
Ultimately, the healthier your ANS is, the more easily you’ll be able to adapt to what life throws at you. What’s interesting is that starting to see a dip in your HRV can predict illness. In more severe cases, low HRV can indicate depression, anxiety, and even an increased risk of heart disease. Concurrently, if you have a higher HRV, it can indicate you’re in great cardiovascular shape and more adept at managing stress.
Tracking your HRV is important because now, armed with this knowledge, you can take steps that lead to improvements in your overall health. If your HRV is lower, then you can make a commitment to exercise, meditate, and sleep more deeply, and then track any (hopefully positive) changes in your HRV. In other words, you can keep tabs on your nervous system, as well as monitor your emotions and thoughts more clearly.
How Is HRV Measured?
The old-fashioned way to measure HRV is with an electrocardiogram (EKG)—you might be familiar with this if you’ve had the wires of an EKG machine attached to you during an annual physical. Of course, this is not practical if you’re trying to measure this on a nightly basis.
There are newfangled approaches to measuring HRV while you sleep, including the Oura ring and the Emfit QS; the former is a wearable ring, while the latter is a “passive under-mattress sensor.” In conjunction with apps, they dig deeper into your sleep to provide data like your HRV, sleep trends, body temperature variations, and more.
While these are more cutting-edge solutions, there are other options. This health.harvard.edu article states that:
“The easiest and cheapest way to check HRV is to buy a chest strap heart monitor (Polar, Wahoo) and download a free app (Elite HRV is a good one) to analyze the data. The chest strap monitor tends to be more accurate than wrist or finger devices. Check your HRV in the mornings after you wake up, a few times a week, and track for changes as you incorporate healthier interventions.”
So you obviously have options if you’re interested in determining your HRV—it just depends on how intrusive or passive you want the process to be.
How Can You Use HRV Data to Your Advantage?
We touched on one way to use HRV info to your advantage—if you know yours might be too low, you can start making those lifestyle changes. However, a lot of the buzz around HRV is about how it can aid in recovery. Both the Oura ring and Emfit system provide what basically amounts to a recovery score.
Having this information can be helpful; if you’re not fully recovered based on the data, maybe you change your training plans for that upcoming marathon or attempt smaller, easier tasks at work. However, if the data shows you are in fact fully recovered, then you can tackle your toughest workout that day, or dig in on that challenging project at the office.
With HRV Comes Great Variability
Like with most health-related matters, each person has a unique HRV reading, and the results might mean one thing for one person and something completely different for another. Beyond that, you can never make assumptions, either. Sometimes a low HRV reading isn’t bad, and a high one isn’t good.
But if you’re reading this, you’re probably interested in tracking your sleep, whether that’s along the lines of determining HRV or your body temperature variations, all for the sake of getting better sleep, and recovering overnight as much as possible. So if you’re already tracking your sleep in some capacity, but haven’t been monitoring HRV, it’s a measurement that’s probably worth tracking.
While our products are temperature-centered, all we really care about is helping you get better deep sleep so you can live a fulfilling life. So if you have any tips or stories around data-tracking and how it helped you achieve your goals, we’d love to hear them.