How Hrv Is Recorded
Using heart rate variability in your day-to-day life is not simple, though. Your HRV readings will change throughout the day, even if theres no obvious stimulus to bring about such changes. And it will naturally be affected by stress and exercise, wherein your sympathetic nervous system grabs the wheel and causes your heart rate to rise.
Results will also vary between people, not solely linked to obvious factors like fitness, so you should really only compare your own results over time. Dont fall into the trap of being jealous of your friends video game-style high scores.
Garmin uses it to feed into training recommendations, for example. It gives you insight to make a clearer decision on how hard you want to go on your training. HRV Status feeds into the other metrics like training status, suggested workouts for even better feedback and guidance, Garmin told us.
However, when we measure HRV we are also not interested in the rate of change of your heart rate during exercise look to a metric like VO2 Max for that. Instead, HRV is typically recorded when there is no obvious stimulus that is going to skew the results, such as when you are asleep.
There are reasons your resting heart rate and estimated VO2 Max are typically more useful, and easier to understand, than metrics for the average person just looking to stay healthy. However, we are starting to see HRV scores given greater prominence in fitness tracker apps.
Engage In Cold Therapy
Exposing the body to cold temperatures for a limited amount of time has shown tostimulate the vagus nerve, which is the main component of the parasympathetic nervous system.
Some ways that you can do this at home include taking cold showers, ice baths or even jumping into a cold pool. Alternatively, if you find yourself so inclined, you could even seek out a cryotherapy spa in your area.
Causes Of Low Heart Rate Variability
The causes of low heart rate variability as said above is due to many reasons and usually, it is due to the below situations
- External stressors
- Internal stressors
Generally, when in resting-state a low HRV is unfavorable however when the body is in the active state a low HRV is favorable.
Even low heart rate variability can also be due to stress as heart rate variability and stress are linked to each other. Often, heart rate variability decreases in stress no matter where it comes from and how it is.
Similar interlinks between HRV and stress anxiety and heart rate variability are also related. Studies have found that anxiety leads to reduced HRV.
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Mistake 1 Assuming A Low Reading Is Always Bad
Chronically low Heart Rate Variability is generally not favorable. However, a single or handful of low HRV readings is not always bad. In fact, strategic acute drops in HRV can be favorable as long as HRV recovers to normal or better levels. Here are a few situations where a low acute HRV is actually desirable.
An acute HRV drop after a hard workout or series of workouts that returns back to normal or better within a few days or weeks time. To maintain fitness and health over the long run, you need to have some periods of physical stress and recovery. Failing to adequately stress the body fails to stimulate adaptation, growth, and improvement. Hormetic stressors cause positive adaptation and improvement and keep the system running optimally. Having occasional, strategic drops in HRV with returns to normal or better helps you know that you are adequately stressing your body for long-term growth and adaptation.
Strategic acute drops in HRV can be favorable as long as HRV recovers to normal or better levels.
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Is It Better For Your Hrv To Be Low Or High
Low HRV may mean that your fight-or-flight response is dominating, leading to fewer variations between heartbeats. This may be triggered by negative situations, such as stress or lack of sleep. Low HRV may thus indicate poor health that can contribute to mental health problems such as depression and anxiety and even some cardiovascular diseases.
High HRV may occur when the relaxation response is more activated, resulting in decreased time between heartbeats. This may be seen when you are relaxed. In this state, you have more flexibility and resilience in switching between low and high heart rates. High HRV may thus indicate better cardiovascular health and the ability to cope better with stressful situations.
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Psychological And Social Aspects
There is interest in HRV in the field of psychophysiology. For example, HRV is related to emotional arousal. High-frequency activity has been found to decrease under conditions of acute time pressure and emotional strain and elevated anxiety state, presumably related to focused attention and motor inhibition. HRV has been shown to be reduced in individuals reporting to worry more. In individuals with post-traumatic stress disorder , HRV and its HF component is reduced whilst the low-frequency component is elevated. Furthermore, PTSD patients demonstrated no LF or HF reactivity to recalling a traumatic event.
The neurovisceral integration is a model of HRV that views the central autonomic network as the decision maker of cognitive, behavioral and physiological regulation as they pertain to a continuum of emotion. The neurovisceral integration model describes how the prefrontal cortex regulates activity in limbic structures which act to suppress parasympathetic nervous system activity and activate sympathetic nervous system circuits. Variation in the output of these two branches of the autonomic system produces HRV and activity in the prefrontal cortex can hence modulate HRV.
Heart Rate Variability And Mortality
Heart rate variability is not only a marker of vulnerability to stress and a measure of one’s capability for adapting to and recovering from stressors, but also an independent predictor of all-cause mortality.
People with a higher heart rate variability have more capacity to adapt and recover from stress more effectively, and they are also certainly more protected health wise, especially from stress related disorders and diseases.
Low heart rate variability is a marker for cardiovascular disorders such as coronary heart disease, hypertension, ventricular arrhythmia, and heart failure. In fact, lowered heart rate variability has been associated with increased risks for ventricular fibrillation, ventricular tachycardia, and even sudden cardiac death following a heart attack.
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Hrv In The Apple Watch
Apple introduced HRV readings to the Apple Watch in WatchOS 4 back in 2018 and it remains available on their latest offering, the Apple Watch Series 7 . They are taken automatically, in the background, at suitable times. However, you can also manually collect HRV data by starting a Breathe session in the Mindfulness app.
You wont see the result when you finish the 1-minute breathing exercise, though. The data is ferried over to the Apple Health app. If you tap All Health Data from the apps home screen you should see an entry for Heart Rate Variability.
This takes you to a screen that shows your HRV over time, with optional timescales of a day, week, month, 6-month period or a year. Its a sensible way to relay the data, sitting outside of the regular fitness area and encouraging you to look at trends and averages, not single results.
Heart Rate Variability Reflects Your Nervous System
HRV is linked to your autonomic nervous system and the balance between the parasympathetic and sympathetic branches. By balancing the two forces, the ANS helps you respond to daily stressors and regulate some of your bodys most important systems, including heart rate, respiration, and digestion.
HRV is the most effective way of estimating your ANS balance, as it directly impacts your hearts activity.
Independently, your heart beats to its own rhythm thanks to a built-in pacemaker called the sinoatrial node. Your SA keeps your heart firing at around 100 beats per minute.
However, your ANS greatly influences how your heart beats. All the cells within your hearts pacemaker have direct phone lines from both sides of your ANS. They give input, beat to beat, on a cellular level to your heart:
- Your rest-and-digest tells your heart to slow down, making room for variability between beats
- Your fight-or-flight system tells your heart to speed up, limiting space for variability
These two systems can be silent, active, or shouting over each other at any given time. Thats a lot of conversation, and it leads to a lot of variation.
As a rule of thumb:
- Higher HRV is associated with rest-and-digest, general fitness, and good recovery
- Lower HRV is associated with fight-or-flight, stress, or illness
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What Do Hrv Variations Mean
HRV variations are a sign that your body is trying to return to its normal state .
High variation usually means that your body is adapting to stress. This can come from training or other stressors. If your variation is high and youre not training that usually means that youre stressed, either physically, chemically, or emotionally.
Having a low HRV means that your body is at or near homeostasis. If your daily readings are at or near your baseline levels, your body isnt getting enough stress or stimulus to adapt.
Experiment with different exercises to learn what lowers your HRV and what activities help raise your HRV. If the variation is high from day-to-day absent training, youre either stressed or youre not measuring consistently.
Record and compare your variations with how you feel. Do they match? If your HRV is low do you feel stressed? Use both methods to get a full view of your health.
The Science Of Heart Rate Variable
The heart beats approximately 100,000 times per day or 2.5 billion times during an average lifetime. Heart rate variability refers to the variability between successive heart beats, specifically the R-R intervals on an EKG recording. If a person has a heart rate of 60 beats per minute, the average R-R interval would be 1 second but some R-R intervals may be 0.8 seconds and others 0.12 seconds.
The variability between successful beats determines the HRV level, as well as its subcomponents. The vagus nerve has the greatest impact on heart function, as the cardiovascular afferents make up the greatest extent of the 85-90% of sensory fibers which make up the vagus nerve. These afferents go through the nodose ganglion which sits in front of the atlas , thus giving a structural reason why upper cervical instability can affect HRV.
Emotional, financial, structural or physical stress causes the heart rate to increase. The fast heart rate results in the time between heart beats to be very small. This coupled with the fact that breathing is very shallow results in a low HRV.
Once baseline measurements are taken, they can be compared with those taken when with the patient under various stressors. As health improves, the changes in HRV from baseline lessen. The stronger the PSNS, the better the patient is able handle any stressor!
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Duration And Circumstances Of Ecg Recording
Time domain methods are preferred to frequency domain methods when short-term recordings are investigated. This is due to the fact that the recording should be at least 10 times the wavelength of the lowest frequency bound of interest. Thus, recording of approximately 1 minute is needed to assess the HF components of HRV , while more than 4 minutes are needed to address the LF component .
Although time domain methods, especially the SDNN and RMSSD methods, can be used to investigate recordings of long durations, a substantial part of the long-term variability is daynight differences. Thus, long-term recordings analyzed by time domain methods should contain at least 18 hours of analyzable ECG data that include the whole night.
How To Maintain A Normal Range Of Heart Rate Variability
Although genetic factors have a high say in this matter one can maintain a normal range of heart rate variability by maintaining proper health, sticking to a fitness regime, managing stress, and following recovery methods like meditation. As a thumb rule maintaining a stress-free life is the base rule for a normal range of HRV.
Although exact heart rate variability range is a tricky one to answer knowing it is good as you can be aware of your health condition by tracking HRV.
Sudheendra is a passionate blogger for 8 years and holds a Degree in Journalism & Mass Communications. His writings particularly focus on health, medicine, diet & lifestyle. For him, everything that interlinks and relates to health & medical world entices him. His write-ups aim at educating people not by just giving facts but by infusing human touch.
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What Does Hrv Mean For Your Health
Why should we care about HRV in the first place? A stack of studies have been undertaken over the years that link it to several different aspects of health. A meta-analysis published in Psychiatry Investigation concluded that HRV is impacted by stress and that it can be used in the objective assessment of psychological health and stress. A low HRV score is an indicator of stress, then.
A large data set study by Fitbits research team that was published in The Lancet found HRV is impacted by exercise, making it a potential metric to judge how well you are managing your workout routine. HRV goes down directly after exercise, but after recuperating a regime that progresses your fitness should see a general upward trend in HRV results.
One 2018 study published in Aging also proposed the use of HRV as a way to predict heart attacks, although it concluded further research was needed.
The ways to interpret HRV may seem amorphous, but this is because it relates to one of the core functions of the human body. Its an indication of the interplay between the sympathetic and parasympathetic nervous systems. One of these, the sympathetic, releases hormones to increase your heart rate, while the parasympathetic releases the hormone acetylcholine to lower it.
A higher HRV suggests your cardiovascular system is more readily adaptable, and thats a good thing.
Where Can I Locate Resting Heart Rate On My Apple Device
From the Health app, tap on Browse and then choose Heart. You will find your Resting Heart rate details on the third row of the screen.
According to Mayo Cliniadults, normal resting heart rates range from 60 to 100 beats per minute.
Generally, a lower heart rate at rest implies more efficient heart function and better cardiovascular fitness.
For example, a well-trained athlete might have a normal resting heart rate closer to 40 beats per minute.
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Your Maximum Heart Rate
The rate at which your heart is beating when it is working its hardest to meet your bodys oxygen needs is your maximum heart rate. Your maximum heart rate plays a major role in setting your aerobic capacitythe amount of oxygen you are able to consume. Several large observational studies have indicated that a high aerobic capacity is associated with a lower risk of heart attack and death. And a small controlled trial demonstrated that men and women with mild cognitive impairment who raised their aerobic capacity also improved their performance on tests of memory and reasoning.
Now Lets Make Some Adjustments
So far we have seen how HRV data can be used to better understand how we are responding and adapting to various stressors. While this is a key first step towards improved health and performance, we have not made any changes yet.
In my opinion, HRV should be used as a continuous feedback loop, so that in the long term, what you improve is health and performance , and not HRV itself. This is different from for example even just resting heart rate , which typically is highly correlated with changes in cardiorespiratory fitness and reduces as you get more fit. This is also why HRV is not a good predictor of fitness .
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Target Heart Rates Chart
What should your heart rate be when working out, and how can you keep track of it? Our simple chart will help keep you in the target training zone, whether you want to lose weight or just maximize your workout. Find out what normal resting and maximum heart rates are for your age and how exercise intensity and other factors affect heart rate.
Avoid Drinking And Smoking
Smoking cigarettes can cause detrimental effects to your overall cardiovascular health. It can trigger numerous heart conditions and also drastically lower your heart rate. Drinking alcohol can also potentially cause a decrease in our HRV for up to 5 days. Combining both habits often leads to the overall deterioration of cardiovascular functions so its always important to pick healthier lifestyle choices.
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Can You Improve Hrv
Understanding and monitoring your HRV over different points of time can help you determine how your nervous system is responding to different situations, thus giving you the information you need to develop strategies for keeping calm and performing your best under a wide variety of circumstances.
How Do You Feel
How you feel is an important part of capturing context around your measurements. Sometimes your subjective feeling will be in line with what you see in the data . Other times, the data might capture stressors that are not obvious yet . Subjective feel and HRV are not supposed to reflect the same aspects or align over time.
Despite how some try to antagonize subjective feel and objective data, it is fairly obvious that subjective metrics and being able to assess how we are feeling is very important. This is why we include a questionnaire after the measurement so that you can take a minute to pause, and self-assess how you are feeling subjectively, a key part of the process.
The data can typically aid this process. As you gather more data, you can learn to fine-tune your subjective feel and assessment based on your objective response to the various stressors you face.
A smart coach, educator or athlete, understands that training load, HRV, and subjective metrics all provide important information that needs to be integrated daily, to decide the better course of action.
There is no winner between objective and subjective metrics, they all serve a purpose.
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