There’s a myth that your heart beats like a metronome. But that’s not the case. Your heart’s rhythm changes ever so slightly between beats. How much the intervals between your heartbeats vary is known as your heart rate variability, or HRV.1
HRV is a health metric that reveals how well your autonomic nervous system is functioning. It shows how well you’re adapting to stress and can signal if your nervous system is off balance.
In this article, we’ll cover what heart rate variability is, what it says about your health, and how you can improve your HRV.
What is heart rate variability?
Heart rate variability measures how much the intervals between each heartbeat change.
Say your heart rate is 60 beats per minute. That doesn’t mean your heart is beating every second like clockwork. Between each heartbeat, there are subtle variations in time.
For example, you may have 0.85 milliseconds between two heartbeats, and then 1.1 milliseconds between the next two. These spaces between your heartbeats are called RR intervals—and how much they fluctuate determines your HRV.
How HRV relates to your health
Heart rate variability reflects the balance of your autonomic nervous system (ANS). Your ANS is made up of two branches: the sympathetic nervous system and the parasympathetic nervous system.
Your sympathetic nervous system (SNS), also known as your “fight or flight” response, is activated when you’re under stress. The stressors could be physical, like an illness or intense workout, or emotional, like a breakup or losing a loved one.
When your sympathetic nervous system is dominant, your body goes into emergency mode. Your heart rate and blood pressure rise, breathing becomes shallow, and energy is diverted away from non-essential tasks like digestion.2
This sympathetic state is meant to be short-term, lasting only until the emergency passes. But due to the fast pace of modern life, many spend the bulk of their days in a state of chronic stress.
Thankfully, your parasympathetic nervous system (PNS), also known as the “rest and digest” response, counterbalances the sympathetic nervous system’s effects. When your PNS is dominant, your heartbeat slows down and you feel calm and relaxed.
Both branches constantly send signals to your heart. Your heart rate variability assesses how well your body is responding to both branches, or whether one branch is more active.
- High HRV means the intervals between your heartbeats vary. A high HRV suggests that your nervous system is responding well to both branches. People with a higher HRV tend to be fitter, more resilient to stress, and have greater overall well-being.
- Low HRV means the intervals between your heartbeat are fairly steady. Having a low HRV suggests that one branch (usually the SNS), is more dominant. This implies that you’re spending more time in “fight or flight” mode and are less tolerant to stress. Low HRV is also linked with several chronic illnesses, including cardiovascular disease, diabetes, and depression.3 4 5
What is a “normal” heart rate variability?
HRV is measured in milliseconds and can range anywhere from 20 to 200 for adults.
But heart rate variability is a super-sensitive metric. It fluctuates not only throughout the day, but from one day to the next.
And there are many factors that can affect your HRV, including:
- Age: HRV decreases rapidly between ages 20-50, then slows, and subtly increases after age 70.6
- Gender: Generally, males tend to have a higher HRV than females.
- Sleep: The quality, duration, and consistency of your sleep all affect your HRV.
- Exercise: Athletes and people with high levels of physical fitness tend to have a higher HRV. That said, exercise is a physical stressor. So your HRV temporarily drops right after an intense workout. But after you recover, your HRV rises.
- Illness: HRV is sensitive to all forms of stress including infections. If your body is battling an illness, your HRV will drop.
- Alcohol: Drinking alcohol can lower your HRV and increase your heart rate.7 8
- Water consumption: Staying well hydrated helps your blood circulate and may improve your HRV.9
- Diet: People who eat diets high in trans fats and unsaturated fats tend to have a lower HRV. On the flip side, people who eat healthful diets, such as the Mediterranean diet, tend to have a higher HRV.10
As you can see, “What’s a normal heart rate variability?” is a loaded question. HRV varies greatly from person to person depending on age, gender, and lifestyle.
That said, if you’re curious about what an average HRV looks like for your age and gender, check out the chart below. It’s derived from a population-based study from the Netherlands that collected HRV measurements from over 153,000 participants.11
Average Heart Rate Variability Chart by Age & Gender
|
Age
|
Gender
|
Mean HRV (in ms)
|
|
20-24
|
Female
|
64.7
|
| |
Male
|
57.3
|
|
25-29
|
Female
|
58.0
|
| |
Male
|
52.1
|
|
30-34
|
Female
|
51.6
|
| |
Male
|
45.4
|
|
35-39
|
Female
|
46.0
|
| |
Male
|
39.9
|
|
40-44
|
Female
|
41.0
|
| |
Male
|
35.2
|
|
45-49
|
Female
|
35.6
|
| |
Male
|
31.6
|
|
50-54
|
Female
|
31.8
|
| |
Male
|
28.7
|
|
55-59
|
Female
|
27.2
|
| |
Male
|
26.2
|
|
60-64
|
Female
|
25.2
|
| |
Male
|
24.8
|
|
65-69
|
Female
|
22.9
|
| |
Male
|
24.4
|
|
70-74
|
Female
|
25.2
|
| |
Male
|
27.2
|
|
75+
|
Female
|
24.0
|
| |
Male
|
25.4
|
Keep in mind that these are average HRV measures from one study. Your HRV could be much higher or lower for your age range depending on your diet, lifestyle, and fitness level.
How to test for heart rate variability
Testing your HRV regularly can give you an idea of how well you’re responding to stress. And thanks to modern technology, there are many ways to check your HRV.
An electrocardiogram (ECG or EKG for short), is considered the gold standard for measuring heart rate variability. During an EKG, sensors are attached to the chest to measure your heart’s electrical activity. This test is highly accurate and is typically done in medical settings to assess heart function.
Fitness trackers and chest straps offer a more convenient and less invasive way to keep tabs on your HRV. Many athletes and fitness enthusiasts use these devices to plan their workout recovery. While these devices are handy, they’re not as accurate as an EKG.
Another option for checking your HRV is transdermal optical imaging (TOI). TOI is a new technology that measures heart rate, breathing rate, HRV, and more based on facial blood flow changes. Research shows that it’s a highly accurate way of assessing HRV, comparable to EKG.12 And all you need is a digital camera and an app.;
Since HRV varies, you won’t get an accurate picture from measuring one moment. So regardless of which method you choose, it’s best to measure HRV over several weeks. This gives you a clearer picture of how your nervous system is working and helps identify any long-term trends.
How to improve heart rate variability
You can improve your heart rate variability by maintaining a healthy lifestyle. Regular exercise, quality sleep, and eating a nutritious diet can all help move your HRV in a positive direction.
In particular, eating plenty of foods high in omega-3s and B vitamins is shown to improve HRV.7
- Foods rich in omega-3s include oily fish, nuts, and seeds.
- Foods rich in B vitamins include leafy greens, eggs, legumes, citrus fruits, poultry, and beef.
Managing stress and setting aside time for relaxation are also crucial to keeping your HRV healthy. Here are some practices that can help reduce stress:
- Meditation
- Deep breathing
- Spending time with friends and family
- Journaling
- Yoga
- Spending time in nature
- Playing with a pet
- Massage
- Mindfulness
- Listening to calming music
- Learning to say ‘no’ and setting healthy boundaries
Keeping tabs on your HRV can help you assess how well your lifestyle habits are working for you.
For example, if you start meditating every day and heading to bed earlier, you may notice your HRV rise. But if you overindulge on alcohol and eat poorly, your HRV may take a dip. This can serve as a wake-up call to get you back on track with a healthier lifestyle.
Key takeaways
Heart rate variability is a health metric that offers clues about the health of your nervous system. In essence, it shows how well your body is adapting to stress. But HRV is a complex metric—and is affected by age, gender, and lifestyle habits.
And while HRV is a helpful tool, it’s only one piece of your health puzzle. It’s important to use other health assessments to get a more comprehensive picture of your health and well-being.
About Mindy Palmer
Mindy Palmer is a wellness writer and certified holistic health coach. She enjoys inspiring others to live healthier lives by creating informative content for leading-edge health and wellness brands.
Sources:
1. Shaffer, F. & J.P. Ginsberg. “An Overview of Heart Rate Variability Metrics and Norms.” Frontiers in Public Health 5, no. 258 (2017).
2. Waxenbaum, J.A., V. Reddy, & M. Varacallo. “Anatomy, Autonomic Nervous System.” National Library of Medicine. Ncbi.nlm.nih.gov.
3. Singh, J.P, M.G.Larson, et al. “Reduced Heart Rate Variability and New-Onset Hypertension.” Hypertension 32, no. 2 (1998): 293-297.
4. Benichou T., B. Pereira, et al. “Heart rate variability in type 2 diabetes mellitus: A systematic review and meta-analysis.” PLOS One 13, no. 4 (2018).
5. Hartmann, R., F.M. Schmidt, et al. “Heart Rate Variability as a Clinical Indicator of Depression.” Frontiers in Psychiatry vol. 9 (2019).
6. Zulfigar, U., D.A. Jurivich,et al. “Relation of Heart Rate Variability to Healthy Longevity.” The American Journal of Cardiology 105, no. 8 (2010): 1181-1185.
7. Spaak, J., G. Tomlinson, et al. “Dose related effects of red wine and alcohol on heart rate variability.” American Journal of Physiology 298, no. 6 (2010): 2226-2231.
8. de Zambotti M., M. Forouzanfar, et al. “Impact of evening alcohol consumption on nocturnal autonomic and cardiovascular function in adult men and women: a dose-response laboratory investigation.” Sleep 44, no. 1(2021).
9. Carter, R., S.N. Cheuvront, et al. “The influence of hydration status on heart rate variability after exercise heat stress.” Journal of Thermal Biology 30, no. 7 (2005): 495-502.
10. Young, H.A., & D. Benton. “Heart-rate variability: a biomarker to study the influence of nutrition on physiological and psychological health?” Behavioural Pharmacology 29, no. 2 (2018): 140-151.
11. Tegegne, B.S., T. Man, A.M. van Roon, et al. “Reference values of heart rate variability from 10-second resting electrocardiograms: the Lifelines Cohort Study.” European Journal of Preventive Cardiology 27, no. 19 (2020): 2191–2194.
12. Wei., J., H. Luo, et al. “Transdermal Optical Imaging Reveal Basal Stress via Heart Rate Variability Analysis: A Novel Methodology Comparable to Electrocardiography.” Frontiers in Psychology, vol. 9 (2018).
