What is Heart Rate Variability (HRV) & why does it matter? | Firstbeat Blog (2024)

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What is heart rate variability HRV & why does it matter? ›

Heart rate variability is where the amount of time between your heartbeats fluctuates slightly. Even though these fluctuations are undetectable except with specialized devices, they can still indicate current or future health problems, including heart conditions and mental health issues like anxiety and depression.

Heart rate variability (HRV) is the change in time between successive heart beats.

HRV is a highly sensitive metric and responds uniquely for everyone. As a rule of thumb, values below 50 ms are classified as unhealthy, 50–100 ms signal compromised health, and above 100 ms are healthy.

High HRV is generally considered an indicator of a healthy heart, and higher HRV has been found in many studies to be associated with reduced morbidity and mortality and improved psychological well-being and quality of life.

“What is a Good HRV Score for Me?” The average heart rate variability for all WHOOP members is 65 for men and 62 for women. For 25-year-olds it's 78, for 35-year-olds it's 60, for 45-year-olds it's 48, and for 55-year-olds it's 44.

A consistent baseline score of 70 or higher is associated with health; whereas levels between 50 and 70 are compromised health and diseases; whereas a regular HRV below 50 puts the person at risk for catastrophic illness and even death.

HRV can detect stress levels. People with low HRV can easily experience acute stress while people with high HRV rarely experience stress and their cardiovascular system is in great shape. Checking your HRV can help you understand how to respond to stress in a healthier way.

Higher HRV (or greater variability between heart beats) usually means that the body has a strong ability to tolerate stress or is strongly recovering from prior accumulated stress. At rest, a high HRV is generally favorable and a low HRV is unfavorable.

Low HRV may mean that your fight-or-flight response (sympathetic arm of the ANS) is dominating, leading to fewer variations between heartbeats. This may be triggered by negative situations, such as stress or lack of sleep.

A normal HRV for people in their teens and 20s averages between 55 and 105 milliseconds, but most folks aged 60 years and up have lower heart rate variability, averaging between 25 to 45 milliseconds.

What should your heart rate be while sleeping? ›

Average Heart Rates While Sleeping

During sleep, it is normal for a person's heart rate to slow down below the range for a typical resting heart rate. Between 40 to 50 beats per minute (bpm) is considered an average sleeping heart rate for adults, though this can vary depending on multiple factors.

Healthy individuals will have scores of 60-70 (depending on age), and top endurance athletes can have numbers of 90-100 (or even higher). Conversely, less healthy people will have numbers in the 40-55 range, and anything below that indicates a low level of vagal activity, which may be a cause for concern.

This indicates that, as expected, low HRV is associated with high scores for fatigue, autonomic dysfunction, sleep quality, anxiety and depression symptoms.

How Can I Improve My HRV? Healthy behaviors like exercise, hydration and proper nutrition, avoiding alcohol, and getting good quality sleep will all have a positive impact on your heart rate variability.

A normal HRV for adults can range anywhere from below 20 to over 200 milliseconds. * The best way to determine your normal level is to use a wearable that measures your HRV in a controlled setting, like sleep, and establishes a baseline over a few weeks.

Chronically low Heart Rate Variability is generally not favorable. However, a single or handful of low HRV readings is not always bad. In fact, strategic acute drops in HRV can be favorable as long as HRV recovers to normal or better levels.

Individuals suffering from an anxiety disorder are characterized by chronically low heart rate variability (HRV) compared to healthy individuals during resting state conditions.

Background—Low heart rate variability (HRV) is associated with a higher risk of death in patients with heart disease and in elderly subjects and with a higher incidence of coronary heart disease (CHD) in the general population.

Heart rate variability in relation to severity of depressive symptoms. Patients with moderate/severe MDD presented with significantly lower HRV measured as the Symindex compared to those lacking depression (p = 0.008) and those with mildly symptomatic MDD (p < 0.049).

Healthy hydration: The science suggests that dehydration has a negative impact on heart rate variability and its recovery after exercise, so it's important to prioritize a healthy hydration routine. This will help improve your HRV and mitigate the effects of an arduous workout.

Should HRV be low while sleeping? ›

Studies show that low sleep HRVs may indicate a sleep disorder such as obstructive sleep apnea, so if yours is consistently low, consider the factors that may affect it: stress levels, bedtime routine, sleep environment, and certain medications or medical conditions.

Longitudinally, HRV measures decreased significantly with aging in both sexes, with faster decline in younger age groups.

Summary: Bradycardia -- a slower than normal heartbeat -- does not increase the risk of developing cardiovascular disease, according to a study.

Cardiac arrest happens when your heart stops beating or beats so fast that it stops pumping blood. During cardiac arrest, people typically collapse and become unresponsive. Symptoms start without warning. This is why it's also known as sudden cardiac arrest.

The heart slows down when we sleep and there can even be pauses between heart beats. Strangely, this is especially true in elite athletes. The longest documented pause is 15 seconds – a very long time to wait for your next heartbeat!

Normal HRV can range anywhere from below 20 to over 200 milliseconds, depending on various factors such as age, biological sex, physical fitness, and genetics.

Why Check Heart Rate Variability? It can identify ANS imbalances. When your system is in fight-or-flight mode, the difference between heartbeats is low as compared to when you are in a relaxed mode where the difference between the heartbeats is high. HRV can detect stress levels.

Low HRV may mean that your fight-or-flight response (sympathetic arm of the ANS) is dominating, leading to fewer variations between heartbeats. This may be triggered by negative situations, such as stress or lack of sleep.

Just as a low HRV reading is not always bad, a high HRV reading is not always good. If a single HRV measurement is abnormally high compared to an individual's baseline or norm, then it can mean something is off. Here are a few examples of when a high reading does not always indicate better health and resiliency.

What causes poor HRV? ›

Many other factors affect autonomic nervous system function and, thus, HRV. HRV decreases with age,⁷ high insulin level,¹⁶ reduced baroreflex sensitivity,¹⁷ physical inactivity,¹⁸ rapid and shallow breathing,¹⁹ smoking,²⁰ depression,²¹ atherosclerosis,⁹ obstructive sleep apnea,²² and diabetic autonomic neuropathy.

What is a good heart rate variability while sleeping? Because heart rate variability is specific to each individual, giving a specific number of recommended beats per minute is difficult. Generally, your heart rate while sleeping should be 20 to 30 percent below your resting heart rate during the day.

Healthy individuals will have scores of 60-70 (depending on age), and top endurance athletes can have numbers of 90-100 (or even higher). Conversely, less healthy people will have numbers in the 40-55 range, and anything below that indicates a low level of vagal activity, which may be a cause for concern.

Use your HRV to define push days: When your HRV is high relative to your baseline, it's a good indicator you can train hard and are likely to recover quickly. On days when your HRV is low, be purposeful about your recovery, both mental and physical.

A normal HRV for people in their teens and 20s averages between 55 and 105 milliseconds, but most folks aged 60 years and up have lower heart rate variability, averaging between 25 to 45 milliseconds.

Conclusions. HRV analysis has become an important tool in cardiology because its measurements are noninvasive and easy to perform, have relatively good reproducibility, and provide prognostic information on patients with heart disease.

Generally, a low HRV (or less variability in the heart beats) indicates that the body is under stress from exercise, psychological events, or other internal or external stressors.

Stress and HRV

With heart rate variability, reported stress unfavorably affects HRV at a 63% frequency. It also occurs a bit more often with women (64%) than men (62%). The average change across the board is a decrease of 4 milliseconds (ms). At the 25th percentile, the drop is 8 ms.