Heart rate variability (HRV) has gotten a lot of attention recently and for good reason, but what’s all the hype about? This post will explore the foundations of HRV, why and how it impacts health and the implications it has for aiding long COVID recovery.
What is Heart Rate Variability (HRV)?
Let's first begin by identifying what HRV is and why it plays such a critical role in our health. Essentially, HRV is a measure of the variation in time between consecutive heartbeats. This variation is controlled by the branch of the nervous system called the autonomic nervous system (ANS). It is helpful to keep in mind that HRV is not the same as heart rate. Heart rate is measured by the number of times the heart beats per minute while HRV is the fluctuation in timing (or variability) between heart beats, also known as the inter-beat interval or R-R interval.
HRV is an important indicator of overall health and is frequently used to evaluate the state of the ANS and how well our bodies can manage stress in our lives. The condition of our health is largely driven by the condition of our nervous system. When the nervous system is working properly, we can feel an abundance of vitality and good health. On the other hand, when the ANS is out of balance, or dysregulated, we can experience a variety of health challenges. Boosting HRV has been found to be particularly beneficial for chronic diseases that affect the ANS (1).
HRV is a non-invasive measure of the activity of the ANS, which controls many of the body's vital functions, including heart rate, breathing, and digestion. A low HRV, meaning less variability between heartbeats, is associated with increased stress and a reduced ability to adapt to changes in the environment. A high HRV (more variability between heartbeats) is associated with a greater ability to cope with and recover from stress.
What Impacts HRV?
There are several factors that can impact HRV, including age, gender, physical activity, sleep quality, stress levels, and overall health. Generally, younger individuals tend to have higher HRV than older individuals, and women tend to have higher HRV than men. Physical activity has also been found to increase HRV, while poor sleep quality and high stress levels can decrease HRV. Certain health conditions, such as heart disease and diabetes, and now long COVID, can also impact HRV (2). It's important to keep in mind that HRV is a dynamic measure that can change over time and can be influenced by various factors. By taking steps to improve overall health and better cope with stress, individuals may be able to improve their HRV and potentially aid in their long COVID recovery.
HRV and Long COVID
Long COVID, also known as post-acute sequelae of SARS-CoV-2 infection (PASC), is a condition that affects some people after they have recovered from COVID-19. The symptoms of long COVID can include fatigue, shortness of breath, chest pain, severe anxiety, depression, heart palpitations, neurological issues, and cognitive impairment (e.g., brain fog). Often, these symptoms can last for weeks or months and can be debilitating for some.
As long COVID symptoms are the result of ANS dysregulation, recent research has suggested that HRV training can be a valuable tool for recovery (3). There are several ways in which HRV can benefit long COVID recovery:
Identifying the severity of symptoms: HRV can help to identify the severity of long COVID symptoms. Individuals with long COVID typically have reduced HRV, which can indicate a dysregulation of the ANS. HRV can help to identify the severity of these dysregulations and can be used to monitor progress during recovery (4,5).
Managing stress: Long COVID can be a stressful and anxiety-inducing experience. HRV biofeedback has been shown to be an effective tool in managing stress and anxiety (6,7). HRV biofeedback involves using a device to monitor HRV and providing visual or auditory feedback to the user to help them regulate their breathing and heart rate. This can help to reduce stress and improve overall health (8).
Improving cardiovascular health: Long COVID can have negative effects on cardiovascular health. HRV is a measure of cardiovascular health and can be used to monitor improvements during recovery. Improving HRV through exercise and other interventions can improve cardiovascular health and reduce the risk of future cardiovascular disease. Although, post-exertional malaise (PEM) is a common symptom of long COVID (9) so exercise and movement are highly subject to individual tolerance and must be pursued with caution.
Enhancing cognitive function: Long COVID can also have negative effects on cognitive function. HRV biofeedback has been shown to improve cognitive function in people with chronic conditions (8,10). HRV biofeedback can improve attention, memory, and decision-making skills, which can help to improve overall quality of life.
What is a Normal HRV Range?
There is no single "normal" HRV range, as HRV can vary widely between individuals and can be impacted by various factors such as age, gender, and overall health. Generally speaking, a higher HRV is considered to be better as it reflects a greater ability of the body to adapt to stress and maintain homeostasis. However, what is considered a high or low HRV may depend on the specific measurement method used and the individual's baseline HRV. It's best to consult with a healthcare professional or use a reliable device to monitor your HRV trends over time and determine what is normal for you.
How to Measure HRV
HRV can be measured using a heart rate monitor or a smartphone app that uses the phone's camera to detect changes in blood flow. Typically, the measurement involves wearing a heart rate monitor that records the intervals between each heartbeat, known as RR intervals. These RR intervals are then analyzed using mathematical algorithms to calculate HRV.
There are several types of heart rate monitors available, including chest straps and wristbands, which can record RR intervals during physical activity and rest. Some devices also come with dedicated HRV measurement features that allow you to track your HRV over time.
When measuring HRV, it's important to understand that we're not simply looking at a single number, but rather a trend over time. To get a more accurate picture of HRV, measurements should be taken over a period of at least a week or two. The more measurements that can be taken, the better. By monitoring HRV over time, you can gain insights into what works best for your body and adjust your lifestyle accordingly to optimize your recovery from long COVID. It's also recommended to consult with a healthcare professional to interpret HRV measurements and determine the best course of action for improving HRV.
Improving HRV
Breath pacing is a simple and highly effective technique that can be used to improve HRV. It involves slowing down your breathing to a rate of around 5-6 breaths per minute, which has been shown (11,12) to increase HRV and decrease stress levels.
To practice breath pacing, find a quiet and comfortable place to sit or lie down, and focus on breathing deeply and slowly. You can use a timer or a breathing app to help guide your breaths and maintain a consistent pace. With regular practice, breath pacing can help improve your HRV and promote relaxation and overall well-being.
Download the Aila Health app to try out some simple paced-breathing practices to improve your HRV.
Summary
In conclusion, HRV can be a useful tool for the recovery from long COVID. It can help to identify the severity of symptoms, manage stress, improve cardiovascular health, and enhance cognitive function. Research is beginning to show that HRV biofeedback can be a helpful tool for managing long COVID symptoms and improving overall quality of life. These days, there are a variety of devices and apps on the market that measure HRV. It is important to keep in mind that there is no specific normal HRV range, as it varies among individuals and can be affected by different factors. Breath pacing and other calming breathing techniques are the most effective way to improve HRV as they tap directly and immediately into the nervous system. If you are experiencing long COVID symptoms, consider speaking to your healthcare provider, or connecting with an Aila Health physician, to learn more about the potential benefits of incorporating HRV into your recovery plan.
Written by: Shannon McLain, PhD
About the author: Shannon is the head of health coaching with Aila Health and specializes in long COVID recovery support. She holds a Ph.D. and master’s degree in mind-body medicine from Saybrook University's College of Integrative Medicine and Health Sciences, where she now serves as a core faculty member in the department of mind-body medicine. Dr. McLain also carries certificates in integrative wellness coaching and integrative and functional nutrition from Saybrook University. Her teaching and practice philosophy is predicated on her commitment to helping each individual reach their fullest potential by achieving a balanced, empowered, and meaningful wellness-oriented lifestyle. She is passionate about educating on the importance of the mind-body connection and the various avenues in which self-healing can be achieved. Shannon recognizes and acknowledges the intimate connection between mind, body, spirit, and person-centered wellness through an integrative and holistic lens.
References
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