HRV is a relatively new metric that measures variations in your heartbeat. There’s no formal guidance on what an optimal HRV is.

Your heart rate variability (HRV) is a measure of the difference between consecutive beats of your heart.

This is a different measurement than your heart rate. Heart rate measures how many times your heart beats in a single minute. Your HRV measures the steadiness of the heartbeats. It’s the measure of how much the beat between each of your heartbeats varies.

For instance, if your heart beats 60 times in a minute, that doesn’t mean your heart will necessarily beat once every second. The timing between heartbeats varies somewhat, so some beats come slightly earlier or later compared to others.

Your HRV is controlled by your automatic nervous system (ANS) and is influenced by factors such as stress, sleep, activities, and mood. Knowing your HRV is one way to gain insight into your health and fitness.

The most accurate way to measure your HRV is to use the results of an electrocardiogram (EKG). An EKG is a test that creates a visual representation of your heartbeats. It allows you and your doctors to see the rate and rhythm of your heart.

On an EKG, your HRV measures between-beat variability. R-R interval is the timing between heartbeats, so HRV is measuring the variability of R-R intervals. You’ll see spikes on your EKG results that represent the R-R phase.

Typically, you’ll need to wear a heart rhythm monitor anywhere from 5 minutes to 24 hours to get an idea of your baseline HRV score. However, you might not need to purchase home health monitoring equipment or make a medical appointment. Today, many fitness trackers and smartwatches, including Apple watches, will track and calculate your HRV for you.

Keep in mind that HRV is a measure that’s mostly used in clinical research. It’s still unclear how useful HRV measurements are outside of this context.

The ideal HRV can depend on a variety of factors, including your overall health and your personal goals.

For instance, athletes sometimes set specific HRV targets. You can also use this information to make lifestyle changes, such as increasing your activity levels or working to reduce your stress levels.

If you track your HRV data at home using a smartwatch or fitness tracker, it’s a good idea to compare your data to your own baseline. Generally, a higher HRV is considered “better” than a lower HRV, but this varies from person to person. If you notice any major shifts in your HRV, talk with a healthcare professional.

You can learn more about HRV by reading the answers to some common questions.

What causes “poor” HRV?

Your HRV can be affected by many factors. These include:

But there are not any guidelines as to what defines a “poor HRV.” If you’re concerned about your heart rate, talk with a doctor about the best way to monitor it.

Is it better for HRV to be high or low?

A high HRV is generally considered more favorable, but there are some medical conditions, such as atrial fibrillation, that can also result in a high HRV.

A low HRV isn’t a medical emergency or a condition that needs treatment. However, it can be a sign of problems with your overall health or of future problems in your health.

How can I improve my HRV range?

There are steps you can take to improve your HRV, including improving overall fitness. You may want to:

Do any medications affect my HRV range?

Certain medications can affect your HRV range, such as:

Heart rate variability is the measure of time between your heartbeats. Factors such as health, stress, sleep, age, gender, and lifestyle may affect your HRV.

HRV is traditionally measured using an EKG. Today, you can get a measure of your HRV at home using a fitness tracker or smartwatch.

There’s no standard recommended HRV range from any major health organization, but if you notice drastic changes in your HRV, consider discussing this with a doctor.