Heart Rate Variability – What It Means For Your Health

Heart Rate Variability – What It Means For Your Health

What is heart rate variability (HRV) and what does it mean?

Heart rate variability (HRV) is the fluctuating amount of time between heartbeats. The idea of using one’s pulse as a part of a diagnosis has been around for centuries, as it can indicate different things about the full picture of a person’s health. It represents how the autonomic nervous system (ANS) reacts to internal and external stimuli.1,2 The ANS is comprised of the parasympathetic (rest-and-digest) and sympathetic (fight-or-flight) and the balance of these helps your response to stressors and regulate important bodily processes. In short, it is supposed to show your body’s response to different stressors or activities. For those with a severe chronic condition, there may be little-to-no variability at all, as opposed to someone with a healthy cardiovascular system. If the heart is beating faster, there is less opportunity for variability between heartbeats. A faster heart rate is associated with a variety of conditions. Ultimately, you want to see that there is a physiological response to stressors and activities.

How do we measure HRV?

In the era of technology developed to help people take control and ownership of their health, measuring one’s heart rate is as easy as wearing your smartwatch and checking your values. Devices including the Apple Watch Series 8, Fitbit Inspire 3, Garmin Forerunner 255, Polar H10, Oura Ring, and Iris Smart Ring all claim to measure HRV among other indicators. In a medical setting, an electrocardiogram (EKG) is used to accurately detect these changes. There are also monitors that individuals with different heart arrhythmias may be sent home with from their provider. The typical range for HRV varies, and you may not know what is normal for you until you can measure this in a controlled setting over a period of time. This number is not a snapshot of health, but rather something that needs to be seen over time.3

What conditions are associated with a poor HRV?

When thinking about heart rate variability, we tend to see a lower measurement with those who have a faster heart rate. There is less time between heartbeats, thus less opportunity for variation. A condition or illness that puts stress on your body can decrease your HRV. Conditions including hypertension, diabetes, obesity, asthma, anxiety, and depression, among others, have underlying processes that contribute to this decreased variability.2,4,5

What can I do to improve my HRV?

You may be wondering what you can do to improve your HRV. Although factors such as age, sex, illness, and many emotional stressors are not able to be controlled, working on building a sleep routine, eating well, implementing or being adherent to medication, and physical fitness are factors that can be modified over time.2,3

There has been evidence that shows poor sleep quality is associated with a decreased HRV. Heart rate decreases during sleep and is related to sleep stage, sleep disturbances, or body movements that occur during sleep. Although there was not a significant relationship between sleep duration and HRV, there was a relationship between sleep efficiency, sleep latency, and HRV parameters. Sleep efficiency is the ratio of total sleep time and total time spent in bed trying to sleep, while sleep latency is the time it takes for you to fall asleep after turning out the lights and trying to sleep. A lack of efficient sleep is typically associated with insomnia, which in turn is associated with psychological distress thus leading to a lower HRV.6

In addition to sleep health, exercise has been associated with positive health outcomes and can increase HRV. A meta-analysis looking at the effect of exercise on HRV in those with type 2 diabetes noted that endurance, resistance, and high-intensity interval training all showed improvement in HRV parameters. The duration and frequency did not necessarily influence the results. The greatest proof was with endurance training (aerobic exercise), but the others did seem to show improvements.7 Exercise is another key piece of maintaining and promoting overall health.

Nutrition is another important piece in improving HRV. There is evidence that a Mediterranean diet, fish, and multivitamins can impact HRV.8 It is widely known that the Mediterranean diet is a balanced, heart-healthy lifestyle modification that has a plethora of health implications. It supports healthy blood sugars, blood pressure, cholesterol, and body weight.9,10 This diet is mainly plant-based with fruits and vegetables, nuts, whole grains, beans, fish, olive oil, and limited amounts of dairy. Since we can see that a poor HRV is associated with chronic disease, the prevention and management of chronic disease is crucial to reflect subjective and objective markers of health.

Conclusion

In conclusion, heart rate variability can help paint a very broad picture of an individual’s health. Essentially, HRV is relatively non-specific, yet poorer health is associated with a poor HRV. As with any health-related measurement that you can receive from your smart device, you should use this measurement as a tool to inform your idea of your overall health. It is incredible to take ownership of your health while remembering to bring your concerns about your smart device metrics to your provider. Ultimately, working on your health holistically may show improvement in heart rate variability. Working towards developing healthy sleep, exercise, and nutritional habits can greatly impact your health and reflect in metrics like HRV. HRV is another way that you can understand your body and how it reacts to your day-to-day experiences.

Written by Katelynn Webster
Edited by Lindsey Dalton, PharmD.

Sources:

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