Checking your pulse on your neck or wrist can give you a good idea of how many times your heart beats per minute. At rest, the average person’s heart beats 60 to 100 times per minute (1).
While your pulse may feel consistent, the timing between heartbeats fluctuates. This results in what’s referred to as heart rate variability or HRV.
This article explains why HRV is important, how to measure it, and what you can do to improve it.
Heart rate variability refers to the fluctuation in the time between heartbeats (
For example, if your heart rate at rest is 60 beats per minute, there’s a good chance your heart isn’t beating exactly each second. Instead, there is variability in the timing between each beat.
If your HRV is high, there’s more fluctuation in the rate. If your HRV is low, there’s less fluctuation between the beats, meaning they occur with more regular time in between.
A low HRV typically means your sympathetic or fight-or-flight response is dominating. A high HRV indicates the parasympathetic or relaxation response is working.
Detecting this variability requires a specialized device like an electrocardiogram machine (EKG) or wearable heart rate monitor.
Heart rate variability (HRV) measures the differences in time between heartbeats. The fluctuations are small and detectable by a specialized device.
HRV and arrhythmia both involve the heart, but they have different meanings.
Arrhythmia refers to the abnormal beating of the heart. It can indicate a heartbeat that is too slow, fast, or erratic (
Stress, smoking, congenital heart defects, and certain medicines or substances can affect your heart’s rhythm (5).
HRV, on the other hand, simply refers to the fluctuation in time between adjacent heartbeats. Everyone’s heart experiences HRV.
In some cases, arrhythmia may result in short-term HRV changes. However, doctors still consider your HRV readings over time (7).
HRV and arrhythmia are not the same. HRV refers to the time between heartbeats. We all experience these intervals, although they differ from person to person. Meanwhile, arrhythmia can be a serious health condition that may require treatment.
According to Inna Khazan, Ph.D., BCB, clinical psychologist faculty at Harvard Medical School, HRV reflects your mind as well as your body’s ability to self-regulate and respond to changes in your internal and external environment.
“HRV is strongly related to overall physical and mental health, physical and cognitive performance, resilience, and ability to respond to stress in healthy ways,” says Khazan.
Greater HRV is associated with better health and performance.
HRV also helps determine how fast your body can shift from fight-or-flight and rest.
“High HRV occurs when your autonomic nervous system is balanced, which means you can adapt well to internal and external stressors — both physical and psychological,” says Danine Fruge, MD and medical director at Pritikin Longevity Center.
If the HRV is low, Fruge says it means your body is working harder to adapt or recover from a stressor. “If your HRV is low for a few days, you may be overtraining, experiencing prolonged stress, or it may even be an early indicator of illness,” she adds.
Fruge says common illnesses that can affect HRV include:
- heart conditions
If you see a consistent trend from high to low HRV, Fruge recommends consulting a physician to interpret your numbers.
HRV helps determine how fast your body can recover after responding to a stressor.
The most accurate way to measure HRV is in a doctor’s office using an EKG. However, this is not always possible or convenient, which is why several companies offer wearable heart rate monitors that allow users to monitor their heart rate metrics 24/7.
A wearable technology option is a traditional heart rate chest strap with a transmitter that’s linked with a receiver wrist device. You may also use a smartwatch or fitness tracker that detects your heart rate via optical sensors, though these may not be sensitive enough.
According to a 2017 study in 50 healthy adults, chest straps often provide more accurate results than wrist-worn heart rate monitors or fitness trackers. Thus, they’re the preferred method of measuring heart rate and HRV outside medical settings (
EKG is the most accurate way to measure HRV, though it requires a medical setting. Outside of a doctor’s office, a wearable chest strap is the most reliable method, followed by wrist-worn smartwatches that detect your heart rate.
The autonomic nervous system regulates your HRV. The system is divided into two components — the sympathetic and parasympathetic divisions.
The sympathetic system is more commonly known as the fight-or-flight response. Meanwhile, the parasympathetic system is better known as the relaxation response (9).
More specifically, the sympathetic branch of the autonomic nervous system increases cardiac output and decreases HRV to respond to stress like exercise or a threat.
When a threat or other stressor passes, the parasympathetic part of the autonomic nervous system increases HRV and slows the heart rate to recover from a stressor (
The autonomic nervous system regulates your HRV. The sympathetic branch is responsible for decreasing HRV and the parasympathetic branch increases it.
A good HRV number depends on factors like your age and overall health.
“HRV ranges are not good or bad, they just indicate changes in your nervous system response,” says Fruge.
That’s why it’s best to talk to your doctor about the best number or range for you. “HRV is very personal and dynamic, so it is important to follow your own baseline and not compare yours to others,” she adds.
Some people notice their HRV fluctuates dramatically throughout the day while others notice their HRV is relatively consistent.
HRV is personal and what might be a good number depends on your health. Therefore, it’s best to work with a healthcare professional to establish what a good HRV for you looks like.
Improving your HRV involves addressing both physical and mental health. Once you determine what affects your personal number, Fruge says you can learn to improve it.
According to Fruge, common lifestyle habits that may improve HRV include:
- deep restorative sleep, with an average of 7–9 hours per night
- daily physical activity
- mindfulness, meditation, and deep breathing for 20 minutes per day
- making the time for self-care
- minimizing alcohol, processed foods, eating late at night, and overworking
There are a number of ways to improve your HRV. These include better self-care, sleep, good nutrition, regular exercise, mindfulness, meditation, and deep breathing.
Most people are unaware of their HRV, though some choose to self-monitor it — for instance, through a smartwatch. However, it’s important to note that smartwatches aren’t sensitive enough to report on routine HRV.
If you notice any concerning patterns, make sure to talk to your doctor.
If a health professional is monitoring your HRV, Khazan says they may ask you to keep an eye out for a drop spanning over a few weeks.
This may be especially important if the drop doesn’t coincide with a clear reason, like increased stress or temporary illness, or if the drop is accompanied by other symptoms.
If you have concerns about changes in your HRV, make an appointment to see your doctor.
Heart rate variability is a helpful tool you can use to monitor your overall health.
Generally, a high HRV is more desirable than a low HRV, because it demonstrates that your body can recover from a stressor.
That said, it’s important to work with your doctor to determine the right HRV for you and find the best way to measure it.