“Heart rate variability is exactly what it says – it’s the variation in the timing of the heartbeat that has to beat.” says Dr. Sameer Mehta, a cardiologist at Denver Heart. HRV is measured in a number of different ways, but popular fitness and sleep trackers like it, , and are among the easiest ways to track it.
Why should you care about HRV? For starters, “There is a variety of data showing that people with a lower heart rate do worse in different ways. Their fitness performance is worse. They have more negative health outcomes, including cardiovascular deaths, myocardial infarctions (heart attacks) and strokes,” says Dr. . Mehta.
HRV can tell you a lot about your sleep, stress, and overall health, making it an important measure to understand. That said, many things can affect your HRV numbers, including your workouts, your diet, and whether or not you are sick. Understanding how sleep and stress can affect HRV can help you avoid potential health problems related to poor sleep and poorly managed or chronic stress.
What affects HRV?
HRV is closely linked to your nervous system, involving many other important health factors such as sleep and stress. To understand HRV a little better, you need to look at how the nervous system functions, as factors that affect the nervous system also affect HRV.
How the nervous system works
The autonomic nervous system consists of the sympathetic and the parasympathetic system. The sympathetic side takes over, “When we are under physical duress, increased stress, depressed, we don’t sleep very well or have consumed more alcohol. Our sympathetic nervous system becomes overactive, which decreases our heart rate variability,” explains Dr. Mehta.
The parasympathetic system is activated when you are more relaxed, well-rested, in shape and in better general health (physical and mental). “And that’s when we see greater heart rate variability,” says Dr. Mehta.
According to Dr. Mehta, low HRV can be caused by these factors:
- Increased stress
- Bad sleep
- Poor diet
- Drug abuse
According to Dr. Mehta, high HRV is linked to the following factors:
- Being physically fit
- Good blood pressure
- Good diet
- Get enough sleep
- Reduce alcohol and substance use
How sleep, stress and HRV are related
Since HRV is affected by sleep, it makes sense that if you get enough sleep each night you will reach a higher HRV. But it’s not all about the number of hours – your sleep quality matters, too.
“When we go into deep sleep, which is a good night’s sleep and more restful sleep, we see increased heart rate variations,” says Dr. Mehta. Conversely, when you don’t get enough sleep, or when your sleep is fragmented or disturbed during the night, your HRV can also suffer.
The connection between sleep and stress
When you are stressed it is more difficult to fall asleep and stay asleep, which can lead to a vicious cycle that makes you feel stressed and tired all the time.
“If you don’t get the sleep you need, you will definitely see a lower HRV and then some sort of lower emotional capacity, which can lead to stress,” explains Emily Capodilupo, VP Data Science and Research at Whoop (a fitness wearable which HRV tracks). “And our bodies just do everything badly when we are sleep deprived, including regulating emotions and dealing with things,” says Capodilupo. It’s all part of a stress-free domino effect that doesn’t benefit your health or HRV.
Dr. Mehta adds that figuring out how to break the stress sleep cycle can start with better sleep and stress hygiene habits. Restful sleep or deep sleep correlates strongly with mental hygiene. So stress management, including eliminating stress and managing stress, he says. Dr. Mehta adds that alcohol is one of the things many people use to deal with stress, which you should avoid as a coping tool, as it can affect your sleep quality, and in turn your HRV.
Addressing poor sleep and high or chronic stress levels is key to maintaining high HRV and, in turn, good overall health. If you struggle with, or have trouble falling or , see your doctor and talk to them about getting tested for underlying health conditions or if you need to seek tests and treatment for sleep disorders. About 30% of people have , and 10% of those people are diagnosed with insomnia, Dr. Deirdre Conroy, clinical director of the Behavioral Sleep Medicine Clinic at Michigan Medicine Sleep Disorders Centers, to CNET.
If you suspect stress is keeping you up at night or interfering with your health in general, consider trying it, which can help you reduce stress and increase mindfulness. If you have trouble coping with stress, seeing a therapist is also helpful, and it’s easier than ever to find a therapist who can . Exercise can also help reduce stress, and you can try restorative exercises, such as if you don’t feel like a heavier workout. By addressing sleep issues and finding healthy ways to deal with stress, you can maintain a higher HRV, which will leave you ready for a healthier future in the long run.
The information in this article is for educational and informational purposes only and is not intended to be health or medical advice. Always consult a physician or other qualified health care practitioner if you have any questions about a medical condition or health goals.