Heart Rate Variability: A Key To Resilience
When you think about your heartbeat, you might consider it like clockwork, always the same lub-dub no matter how fast or slow it goes. But the truth is more interesting: if your heart is always locked into the same pacing, you might be more stressed than you think. Subtle variations in the pacing of your heart indicate resilience and nervous system flexibility, which promotes longevity. These subtle changes in your heart’s rhythm are referred to as HRV, Heart Rate Variability, and we’re going to talk about why it’s important.
Understanding Heart Rate Variability
HRV refers to the time variation between each heartbeat. This might sound like a useless detail, but it's a significant insight into the health of our cardiovascular system and the functioning of our autonomic nervous system (ANS).
The ANS is responsible for those body functions that happen unconsciously, like digestion and heart rate. It is split into two branches: the sympathetic nervous system (SNS), which kicks in during periods of stress, and the parasympathetic nervous system (PNS), which regulates body functions when we are at rest.
HRV gives us a glimpse into the relationship between these two branches of the ANS. A high HRV indicates a healthy balance between the SNS and PNS, showing the body's ability to adapt well to changes and handle stress. On the other hand, a low HRV suggests a dominance of the SNS, indicating chronic stress and a higher risk of health issues.
Why HRV Matters For Longevity
HRV is more than just a measure of stress. It's a window into our health and longevity. A low HRV is linked to a host of health problems, including cognitive decline, sleep disorders, and heart issues. Furthermore, HRV has been shown to decrease with age, reflecting an age-dependent decline in the autonomic nervous system (ANS).
However, this decrease is not inevitable. Several studies have shown that healthier individuals, regardless of their age, tend to have a less severe decline in HRV. This suggests that with the right lifestyle choices, we can influence our HRV and, by extension, our health and lifespan.
HRV and Mental Health
Heart Rate Variability (HRV) is not only a marker of physical health but also of mental and emotional resilience. The connection between mental health and HRV is significant, as psychological states like constantly feeling on edge, low mood, and stress profoundly impact the autonomic nervous system (ANS), consequently affecting HRV.
Nervousness and HRV
A state of constant worry or unease is characterized by heightened sympathetic activity – the fight or flight response. This hyperarousal state can lead to a decrease in HRV, indicating lower resilience to stress and reduced parasympathetic (rest and digest) activity. Studies have shown that individuals with nervous disorders often exhibit lower HRV, signifying a less flexible cardiovascular system.
Low Mood and HRV
Having persistent feelings of no motivation or low emotional states is linked to alterations in autonomic function, particularly a decrease in parasympathetic activity. This reduction manifests as lower HRV, representing a diminished capacity to cope with stress. Research indicates that lower HRV in those with persistently low moods may also be associated with an increased risk of cardiovascular diseases.
Stress and HRV
Chronic stress has a substantial impact on HRV. Persistent stress leads to an imbalance in the ANS, skewing it towards sympathetic dominance. This imbalance is reflected in decreased HRV, highlighting a reduced ability to adapt to changing environmental demands.
HRV and Chronic Conditions
HRV is a valuable tool in understanding and monitoring chronic conditions, like blood sugar imbalances, high blood pressure, and heart dysfunction.
Blood Sugar and HRV
In metabolic disorders, high blood sugar levels can damage nerves and blood vessels, impacting heart function. This damage can lead to a decrease in HRV, which is often observed in patients with blood sugar challenges. Lower HRV in these patients may indicate a higher risk for cardiovascular complications.
High Blood Pressure and HRV
High blood pressure can strain the heart and blood vessels, leading to changes in HRV. Studies have shown that those with hypertension often have lower HRV, reflecting an imbalance in autonomic function.
Heart Dysfunction and HRV
In heart dysfunction, the heart's ability to pump blood efficiently is compromised. This inefficiency affects the ANS and is reflected in HRV. Lower HRV in heart patients can indicate a worse prognosis and can be used to monitor disease progression.
Tracking Your HRV
To gain insights from HRV, we first need to track it. While clinical electrocardiography (ECG or EKG) machines provide highly accurate HRV data, they are not practical for everyday use.
Enter wearable devices. Fitness trackers, smartwatches, and tracking rings offer a more accessible and convenient means of measuring HRV. These devices use photoplethysmography (PPG) or other sensors to monitor heart rate and calculate HRV. While they might not be quite as accurate as EKGs, they offer valuable insights into daily HRV trends.
When choosing a device to track your HRV, consider factors such as the brand's reputation and accuracy, the comfort and durability of the device, and your budget. Some reputable brands that offer HRV tracking include WHOOP, Oura ring, Fitbit, and Polar.
The Oura ring page shows data it’s collected from users who have opted in to share their metrics. While the averages are broad, often with 30–40-point ranges, it serves as a guide for where healthy HRV levels are by age and by biological gender, and reminds a certain writer that this is one area she could improve in:
Improving Your HRV
Improving your HRV is all about building and keeping a healthy lifestyle. Regular exercise, a balanced diet, good sleep, and stress management are all linked to better HRV scores.
Regular Physical Exercise: Consistent, moderate exercise is known to enhance HRV. It improves cardiovascular fitness and regulates the balance between the sympathetic and parasympathetic systems. Activities like brisk walking, cycling, or swimming, performed regularly, can lead to a healthier HRV profile over time.
Diet: Certain dietary habits can positively influence HRV. Diets high in omega-3 fatty acids, B vitamins, polyphenols, and a Mediterranean-style diet can contribute to maintaining a higher HRV. Foods high in saturated fat and high glycemic index carbohydrates can have a negative effect on HRV.
Sleep: Our heart function is affected by our sleep stages. Daytime HRV has been shown to decrease in certain sleep disorders and after a night of poor sleep. Higher HRV during sleep is known to indicate enhanced physical and psychological restoration, meaning higher HRV means better sleep, which means better energy and cognition the next day.
Stress Management: Chronic stress can lead to overactivation of the sympathetic nervous system, which is reflected in a low HRV. HRV thus provides an objective measure of psychological health and stress.
Meditation and Mindfulness Practices: Meditation has a profound impact on HRV by promoting relaxation and reducing stress. Mindfulness meditation, in particular, helps in balancing the sympathetic and parasympathetic nervous systems. It encourages a state of calm, reducing the fight-or-flight response and increasing parasympathetic activity. This shift can lead to an increase in HRV, reflecting improved stress resilience and autonomic flexibility.
Diaphragmatic Breathing: Also known as deep breathing, this technique involves breathing deeply into the diaphragm rather than shallow breathing into the chest. It stimulates the vagus nerve, which is part of the parasympathetic nervous system. Diaphragmatic breathing can lower the heart rate, decrease blood pressure, and increase HRV, thereby enhancing the body's ability to respond to stress.
Biofeedback Therapy: This technique involves using electronic monitoring devices to relay information about the body. Biofeedback helps individuals gain control over certain bodily functions, including heart rate. Through biofeedback, you can learn to induce relaxation responses, thereby positively affecting HRV.
Reducing Alcohol Consumption: Alcohol can have a negative impact on HRV. Chronic alcohol consumption is associated with a reduction in HRV, indicating heightened sympathetic activity and reduced parasympathetic activity. Reducing or stopping alcohol intake can help in restoring HRV to healthier levels. It's not just about abstaining; it's about giving the nervous system a chance to rebalance and function optimally.
Incorporating these techniques into daily life can significantly improve HRV, reflecting a well-balanced autonomic nervous system and contributing to overall health and longevity.
Heart Rate Variability is a powerful tool for measuring health. By giving us valuable insight into our overall health, HRV arms us with the information we need to tackle health problems at the source. Understanding your HRV can help you maintain vibrant health for many more years.
Whether you are a longevity biohacker or just wanting to be the healthiest version of yourself for years to come, HRV is one metric you’ll want to keep close tabs on. So, start tracking your HRV today, and take a step towards better health and longevity.
Remember, your HRV is unique to you. While it's useful to know what a 'good' HRV number looks like, the most important thing is to establish a baseline for your HRV and monitor changes over time.
- Tan JPH, Beilharz JE, Vollmer-Conna U, Cvejic E. Heart rate variability as a marker of healthy ageing. Int J Cardiol. 2019;275:101-103. doi:10.1016/j.ijcard.2018.08.005
- Kiviniemi AM, Hautala AJ, Kinnunen H, et al. Daily exercise prescription on the basis of HR variability among men and women. Med Sci Sports Exerc. 2010;42(7):1355-1363. doi:10.1249/mss.0b013e3181cd5f39
- Young HA, Benton D. Heart-rate variability: a biomarker to study the influence of nutrition on physiological and psychological health? Behav Pharmacol. 2018;29(2-):140-151. doi:10.1097/FBP.0000000000000383
- Tobaldini E, Nobili L, Strada S, Casali KR, Braghiroli A, Montano N. Heart rate variability in normal and pathological sleep. Front Physiol. 2013;4:294. doi:10.3389/fphys.2013.00294
- Kim HG, Cheon EJ, Bai DS, Lee YH, Koo BH. Stress and heart rate variability: a meta-analysis and review of the literature. Psychiatry Investig. 2018;15(3):235-245. doi:10.30773/pi.2017.08.17