If you’re into fitness or training, you may have come across the term HRV—short for Heart Rate Variability. It might sound a bit technical, but it’s gaining more attention, even outside of elite sports circles. So what exactly is HRV, and does it really matter?

What is HRV?

HRV is a measure of the variation in time between each heartbeat. Sounds simple, right? But there’s more to it. Instead of your heart beating like a perfectly timed metronome, the time between each beat actually changes slightly. For example, if your heart is beating at 60 beats per minute, it’s not necessarily beating exactly once every second. Sometimes the gap between beats will be a little longer or shorter.

This variation is what’s known as heart rate variability, and it’s controlled by your autonomic nervous system (the part of your nervous system that manages things like heart rate, breathing, and digestion without you having to think about it). Essentially, your HRV is like a window into how your body is handling stress, recovery, and overall balance.

What Does HRV Tell You, and What Affects It?

Your HRV can give you clues about how well your body is recovering from exercise or handling stress—whether that’s physical, emotional, or mental. A high HRV generally means your body is in a good place. A low HRV, on the other hand, could suggest that your body is feeling stressed or fatigued.

A lot of factors can influence your HRV, in addition to your training and workouts:

Sleep: A good night’s sleep generally leads to a higher HRV.
Stress: Emotional stress (like work pressure or personal issues) can lower your HRV.
Diet: Your eating habits, hydration, and even alcohol consumption can affect HRV.
Illness: When you’re feeling under the weather, HRV often drops.

This is why it’s useful as a big-picture tool for overall health, not just fitness performance

How Do You Measure HRV?

There are quite a few apps and devices out there that can measure HRV.

Some fitness trackers and smartwatches already include it as part of their health monitoring features. Some of the most popular devices that track HRV include:

Apple Watch: Tracks HRV through the heart rate sensor and displays the data in the Health app.
WHOOP Strap: Specialises in performance and recovery metrics, with HRV playing a key role in its analysis of how recovered you are each day.
Oura Ring: Tracks HRV primarily during sleep, offering insights into your recovery and readiness levels.
Garmin Watches: Many Garmin models include HRV tracking, often used to calculate “Body Battery” or “Stress Levels”.
Fitbit: Select Fitbit models track HRV, with a focus on sleep and overall wellness.

When Do You Measure HRV?

Typically, you measure HRV first thing in the morning, while you’re still resting and before the day’s stress, activities, or food intake starts to kick in. Many experts suggest using a consistent time, like first thing in the morning, for accuracy in tracking trends over time:

You wake up, check your HRV, and it’s higher than usual. This could mean you’re well-rested, recovered, and ready for a good workout.
On another day, you wake up and your HRV is lower than normal. This might be a sign that your body needs more rest, or maybe a lighter workout to avoid overdoing it.

However, it’s not a strict rule—some people also measure HRV before bed or at another quiet time during the day. The key is to measure at the same time under similar conditions each day. This way, whether you choose mornings, evenings, or a calm period during the day, you’re more likely to get consistent, comparable readings that accurately reflect changes in your HRV over time.

Many wearables calculate a daily HRV average rather than focusing on individual measurements. Devices like the Apple Watch or Oura Ring track HRV at various points and then calculate an average or a trend for the day. That said though, many of the wearables allow you to take a measure whenever you want to take a one-off reading as well.

This daily average is helpful for gauging your overall autonomic activity across a 24-hour period, as it smooths out the individual fluctuations caused by daily stress, exercise, or other influences. However, if you’re focused on tracking recovery or establishing a consistent baseline, taking a single measurement at the same time each day—such as in the morning—can give you clearer insights. This approach reduces the “noise” from daily variation and helps you see trends in your HRV over time.

Heart Rate Variability (HRV) varies widely from person to person, and what’s considered “high” or “low” can depend on factors like age, fitness level, and individual physiology. That said, here’s a general guide:

Average HRV Ranges

Younger, healthy adults: HRV often ranges from 50–100 ms (milliseconds) as an average baseline, though some can reach much higher values.
Athletes: Some elite athletes may see average HRV values over 100 ms; this is often a sign of high cardiovascular fitness and good recovery.
Older adults: HRV tends to decrease with age. For people in their 40s and 50s for example, a range of 40–80 ms might be more typical.

What’s Considered High or Low?

High HRV: Generally, above 70 ms can be seen as a high HRV for many people. For elite athletes, an HRV over 100 ms could indicate peak recovery and fitness.
Moderate HRV: HRV values between 40–70 ms are often typical for those in decent health and fitness but not at an elite level.
Low HRV: HRV values consistently below 40 ms could be considered low for most adults, suggesting potential issues with stress, recovery, or fitness.

Key Points to Remember

Personal Baselines: Your HRV baseline is unique to you. Instead of aiming for a “universal high,” try to monitor your baseline over time and look for trends.
Daily Variability: HRV can fluctuate daily, so it’s more useful to track weekly or monthly trends.
Trends Matter More: A drop in HRV over a few days might signal stress or lack of recovery, while an increase generally shows your body is in a better recovery state.

So it’s really important to remember that HRV can fluctuate from day to day. It’s not about one-off measurements but more about noticing trends over time. A consistent drop in HRV might suggest that you’re overtraining or stressed, while a steady improvement could indicate you’re recovering well and managing stress effectively.

Should You Care About HRV?

For professional athletes, HRV can be a really useful tool for fine-tuning their training and recovery to squeeze out those extra performance gains. But what about amateur athletes and regular folks? Is HRV something you should be thinking about?

The short answer is: it depends.

If you’re someone who trains regularly and wants to perform at your best, understanding your HRV could be helpful. It might give you insights into when your body needs more recovery or when you’re ready to push yourself harder. It’s like having a little extra feedback on how your body is coping with your training load and life’s stresses.

However, if you’re someone who works out just for fun and isn’t too worried about performance metrics, then you probably don’t need to obsess over HRV. It’s just one of many tools, and you might be perfectly fine listening to your body’s natural signals without the extra data.

Nothing in this blog is intended as medical advice. If you’re concerned about your heart, health or HRV, you should always consult a healthcare professional.