Have you ever wondered why some people seem to bounce back from stress and adversity with ease while others struggle to keep up? The answer may lie in a simple metric known as heart rate variability (HRV). We’ll explore the concept of HRV and how it can be used as a tool to measure and improve your resilience. From regular exercise and deep breathing to mindfulness and healthy eating, I will share the various strategies that can help to boost HRV and enhance overall resilience.
What Is Heart Rate Variability?
Heart rate variability (HRV) is a metric that reflects the variation in the interval between consecutive heartbeats. It is calculated by taking the difference in time between two successive heartbeats and then averaging these values over a period of time. This metric has been widely studied and researched for decades and has been found to be a powerful indicator of our physical and mental resilience. HRV also provides insight into your overall physiological function, including heart and respiratory health, sleep quality, and general wellness.
A study published in the Journal of Applied Physiology found that HRV was significantly lower in individuals with depression, anxiety, and post-traumatic stress disorder (PTSD) compared to healthy individuals. Other research has found that low HRV is also associated with a higher risk of cardiovascular disease and a greater likelihood of developing conditions such as depression and anxiety.
The higher the HRV, the greater the heart rate variation, which indicates a healthy, adaptable autonomic nervous system. Conversely, a low HRV indicates a lack of resilience, as it suggests that the autonomic nervous system cannot respond to stress or adapt to changing circumstances.
Autonomic Nervous System
The autonomic nervous system regulates many of the body’s automatic processes, including heart rate, blood pressure, respiration, pupillary action, sexual arousal, and digestion. It is divided into two branches: the sympathetic nervous system (SNS), which prepares the body for action, and the parasympathetic nervous system (PNS), which helps the body to relax and recover. A healthy and resilient autonomic nervous system will have a balance between the SNS and PNS, allowing for quick and efficient responses to stress, as well as effective recovery after stress.
The Sympathetic Nervous System
The sympathetic nervous system (Fight or Flight) is best known for responding to dangerous or stressful situations. The amygdala in the brain sends out a distress signal to the hypothalamus, which activates the sympathetic nervous system. This alerts the adrenal glands to pump the hormone norepinephrine (adrenaline) into the bloodstream. Increased heart rate, blood flow and oxygenation to tissues prepare the body to escape the actual or perceived threat. Biologically, if a bear confronts us, for example, the sympathetic nervous system gives us that boost of energy to escape. All energy is shunted away from other autonomic responses, such as digestion, to get us to safety. In the modern world, we may not have to outrun lions, tigers, or bears, but our bodies cannot distinguish between a life-threatening event or the stress of sitting in traffic or worrying about bills. This can lead us to be in a persistent state of fight, flight, or freeze, which can have adverse effects on the body. Individuals with a low heart rate variability are often stuck in a fight or flight pattern and tend to have lower resilience and cardiovascular health.
The Parasympathetic Nervous System
The parasympathetic nervous system (Rest & Digest) manages activities in the organs when we are in a state of calm or relaxation. These functions do not involve any danger or risk but are still life-sustaining. Its main job is to relax or reduce the body’s activities, controlling output and response during rest. When the parasympathetic nervous system is engaged, heart rate and blood pressure are lowered, the rate of digestion is increased, and the pancreas is signalled to make and release insulin.
The vagus nerve is the primary nerve of the parasympathetic nervous system. Vagus, from the Latin word for “wandering,” is the longest of all the ten cranial nerves in the body. The vagus nerve helps to counteract the body’s sympathetic fight or flight response, helping regulate stress response and become resilient. Stimulating the vagus nerve benefits the autonomic nervous system and mental and emotional well-being by bringing about relaxation and feelings of calm. Vagal tone is a stop button for stress measured indirectly through heart rate variability.
The gold standard test used to check the function and efficiency of the vagus nerve comes from Heart Rate Variability (HRV). HRV measures autonomic vagal nerve activity; higher HRV indicates better output, increased resilience and a healthier person. HRV is an excellent tool as it assesses nervous system adaptation; the more you can switch back and forth and maintain a balance between the parasympathetic and sympathetic sides of the nervous system, the better you will be able to heal, recover and repair.
In my practice as a chiropractor, I use various tests and tools to measure autonomic nervous system adaptation in my patients and have been for several years. Measuring heart rate variability is an invaluable tool to help me monitor how their body adapts to physical or environmental stressors. It is also a great way to see the impact of chiropractic care on overall nervous system functioning. I can compare their HRV readings and offer guidance or adjust treatment plans based on their current standing. If you are in the Ottawa-East area and would like to schedule an appointment for a chiropractic assessment including the HRV test you can do so HERE.
An improvement in the vagus nerve activity plays a major role in regulating autonomic nervous system function, lowering chronic disease risk, and decreasing mortality rates. Better health and function within the nervous system represent only a portion of the benefits experienced through regular chiropractic care. And very importantly, in the stressful, fast-paced life we often live these days, chiropractic care appears to increase the healing and calming side of our autonomic nervous system.
Tracking Heart Rate Variability
HRV can be measured using several methods, including wearable devices, such as fitness trackers and smartwatches, and standalone HRV monitors. Wearable devices with heart rate monitoring capabilities can provide HRV data through their accompanying apps. These devices can be worn continuously, providing real-time HRV data that can be tracked and analyzed over time. I use an Oura ring to measure mine. Other devices like Whoop, Hanu, Elite RV, Apple Watch and FitBit will all track and measure heart rate variability.
It is important to note that not all these devices are created equal regarding the level of electromagnetic fields (EMF) they emit. Some of these devices constantly transmit information, and being worn directly on the body gives cause for concern. EMFs are a type of radiation that is emitted by electronic devices, including these wearable tools.EMFs have been linked to hormonal imbalance, DNA damage, behavioural changes, headaches, sleep disruptions, and increased risk for certain cancers. One of the reasons I chose the Oura ring for myself is that it is designed to store data locally on the device and only transmit data when I manually sync the device with a smartphone app. This helps me minimize my exposure to EMFs while still enjoying the benefits of this remarkable technology.
I recommend doing your research to find a lower EMF emitting device that fits your budget, or at the very least, limit your exposure by avoiding use overnight, turning it off when not in use, and utilizing airplane mode when you aren’t actively tracking health metrics.
Standalone HRV monitors are another option for tracking HRV. These monitors can be connected to a smartphone or computer and typically use electrocardiogram (ECG) sensors to measure HRV. Standalone HRV monitors often provide more detailed and accurate HRV data compared to wearable devices. Still, they are typically more expensive and less convenient to use daily. Wearable devices have about a 70% accuracy rate, so while they can help give you an idea of your HRV, they may not give you the whole picture. In the clinic, I use a state-of-the-art machine called the Pulse Wave Profiler, which gives me a much more accurate reading. This instrument helps determine my patient’s overall ability to adapt to environmental stressors and monitor the balance and activity of the entire autonomic nervous system.
When tracking HRV, it’s important to keep in mind that various factors, including physical activity, stress, and sleep, can influence HRV. Heart Rate Variability is an extremely sensitive metric. It can vary throughout the day, from one day to the next, and from person to person. Generally speaking, younger adults and athletes will have a higher HRV, while older people will have lower heart rate variability. Heart rate variability is highly individualized. Rather than comparing your HRV to a friend or spouse, tracking your variability over time is better.
To get the most accurate and meaningful HRV data, it’s best to track HRV at the same time each day, ideally in the morning after waking up, and to avoid physical activity and stress immediately before measurement.
In addition to tracking HRV, it’s also important to keep track of other factors that may influence HRV, such as sleep quality and physical activity. Keeping a daily journal to track these factors can provide valuable insight into how they impact HRV, and can help to identify any patterns or trends over time. You want to get a baseline of your variability first and foremost, this will make it easier to notice any changes.
If you are taking steps to better your health and fitness, you should notice an upward trend. Conversely, if you suddenly see lower HRV readings, it could indicate illness, poor sleep quality, improper hydration, or even training too hard.
How to Increase HRV
Improving heart rate variability can be achieved through a variety of simple lifestyle and behavioural changes. Any positive change you can incorporate into your daily routine will help increase your HRV, reduce stress, and improve resilience. Your autonomic nervous system will thank you!
- Exercise & Train Intelligently: Regular exercise is one of the most effective ways to improve HRV, but overtraining can have the opposite effect. Avoiding too much strain and allowing your body to recover is vital to maintaining high HRV levels.
- Smart Nutrition: A healthy diet consumed at regular intervals is important for maintaining a stable HRV. Eating close to bedtime can negatively affect HRV by interfering with sleep, so it’s best to avoid it. Be sure to include whole fruits, vegetables, lean proteins and whole grains, and limit or avoid processed foods.
- Hydration: Staying hydrated is important for HRV, as it ensures that blood circulates easily and delivers essential nutrients and oxygen to the body. Aim to drink close to an ounce of water per pound of body weight each day.
- Avoid Alcohol: Alcohol consumption can reduce HRV by as much as 22 milliseconds the next day and have lingering effects that last up to 5 days. Avoiding alcohol is the best way to maintain high HRV levels.
- Quality Sleep: Getting enough sleep and having a consistent sleep schedule is important for HRV. Regular sleep patterns help maintain the circadian rhythm, enabling you to spend more time in deep and REM sleep. Aim to get 7-9 hours of quality sleep each night and establish a consistent sleep routine to help regulate your sleep cycle.
- Natural Light Exposure: Exposure to natural light, especially in the morning and evening, has been shown to have a positive impact on the body’s circadian rhythm, a 24-hour internal clock that regulates the timing of physiological processes such as sleep and metabolism. By improving the function of the circadian rhythm, exposure to natural light can help to regulate the body’s response to stress and increase HRV.
- Cold Thermogenesis: Brief exposure to cold temperatures (such as cold showers or ice baths) can stimulate the vagus nerve, which helps regulate HRV.
- Intentional Breathing: Controlled breathing techniques have been shown to improve HRV and reduce stress. By slowing down your breath and increasing the duration of exhalations, intentional breathing can activate the parasympathetic branch of the nervous system, promoting relaxation and increasing HRV. Regular, intentional breathing practices can help to improve resilience and reduce stress.
- Mindfulness & Meditation: Practicing mindfulness and meditation can reduce stress, which has a negative impact on HRV. Even just one minute of mindfulness exercises each day can make a difference.
- Gratitude Journaling: Writing down things you are thankful for can increase HRV, lower blood pressure, and reduce stress hormones.
- Chiropractic Care: Chiropractic care improves the function of the nervous system by restoring the balance between the sympathetic and parasympathetic branches. By adjusting subluxations in the spine, chiropractic can reduce nerve interference and improve the flow of information between the brain and the body. This can help to increase HRV and promote a more resilient response to stress.
In addition to the tips mentioned above, it is also important to prioritize self-care by engaging in activities that bring you joy and fulfillment. This can include hobbies, socializing with friends and family, or simply taking time for yourself to relax and recharge. In a previous blog, I give tips for self-care that you may find helpful. You can read it HERE.
By taking a holistic approach to your health and well-being, you can improve heart rate variability and live a more resilient, healthy life.