Aldosterone, which increases our heart rate, challenges our bodies with stress factors such as heat, cold, and dehydration. On the other side, the parasympathetic nervous system lowers heart rate and promotes relaxation and recovery. Its main job is to reduce production of cortisol and adrenaline, which can increase heart rate and trigger a person to feel anxious. The parasympathetic system is active when we sleep or meditate, and is also referred to as the “rest and digest” part of our nervous system. High HRV Reflects Health A healthy level of HRV indicates strong activity in both the sympathetic and parasympathetic systems. High variability in HRV reflects our body’s ability to handle different types of stressors, and can be seen as a biomarker for our overall health and resilience. Conversely, low HRV is associated with an increased risk for chronic health issues, including high blood pressure, obesity, diabetes, and heart disease. HRV and Sleep Quality One factor that cannot be overlooked is the impact that sleep quality has on HRV. Research has demonstrated a strong correlation between HRV and sleep duration. Multiple studies have linked elevated nighttime HRV to sleep that has been of a longer duration—signaling that, in general, longer sleep leads to an increased parasympathetic response when we are sleeping. It is also worth noting that sleep-specific HRV measures are significantly impacted by poor quality of sleep. Arousal-dominated sleep, such as when a person experiences a number of shallow sleep cycles and episodes of wakefulness during the night, has been shown to decrease HRV following the sleep episode. How to Improve HRV Fortunately, HRV can be impacted in relatively short periods of time. There are several steps you can start taking to improve your HRV scores. First, make sure you are getting enough sleep and that it is good quality sleep. While there is no exact prescription for the amount of sleep everyone needs, the National Heart, Lung, and Blood Institute generally recommends at least 7-9 hours per night for adults. You can keep track of how much sleep you are getting by using a sleep tracking app or device, and make changes to improve the quality and duration of your sleep. Additionally, making small lifestyle changes such as exercising (particularly aerobic exercise) and spending time outdoors can help increase heart rate variability. Additionally, consider trying relaxation techniques such as yoga, mindfulness, or meditation. While not a substitute for professional medical advice, there are several relaxation applications and products available that guide users through calming exercises and could potentially be beneficial for improving HRV. Bottom Line It’s no surprise that stress can harm our bodies in the long run, but heart rate variability gives us a way of measuring these effects on our nervous system. By keeping track of sleep duration and quality, and making small lifestyle changes, we can increase HRV and reduce the risk of chronic conditions associated with low HRV.
Understanding Heart Rate Variability
Heart rate variability (HRV) is a measure of the time intervals between heartbeats. It is different from heart rate, which is a measurement of the number of times the heart beats in a minute. Our hearts do not have a fixed tempo, and the time between any two heartbeats constantly changes. HRV is a measurement of the changes in these intervals between heartbeats.
The Relationship Between HRV and Our Nervous System
HRV measures the conflict between two parts of our nervous system – the sympathetic and the parasympathetic. The sympathetic nervous system elevates heart rate and amplifies airflow through the lungs, while the parasympathetic nervous system lowers heart rate and promotes relaxation and recovery. High HRV reflects the body’s ability to handle stressors effectively.
The Link between HRV and Sleep
Sleep is an important factor for regulating and stabilizing HRV. Many studies have linked high HRV to long sleep duration. Poor quality of sleep, such as when a person experiences a number of shallow sleep cycles and episodes of wakefulness during the night, decreases HRV following the sleep episode.
Steps to Improving HRV
The good news is that there are steps you can take to improve your HRV scores. First, make sure you are getting enough quality sleep – at least 7-9 hours per night for adults. Keep track of how much sleep you are getting and make changes to improve the quality and duration. Additionally, exercising (particularly aerobic exercise), spending time outdoors, practising relaxation techniques such as yoga, mindfulness, or meditation can help increase heart