There is a lot of misconception about heart rate variability (HRV) online and in prominent medical papers. If you search “ What is HRV “ you will see two things. First you’ll see some vague articles from Harvard health, WebMD and Johns Hopkins. However, it is not in the interest of big pharma and big medicine to promote HRV because heart rate variability gives individuals true health independence.
The second thing you will see is articles and product placement from some of the top HRV device companies. Here you will see the fireworks, trying to lead you to purchase their products. But there must be an in between; The Truth.
WHAT IS HRV – HEART RATE VARIABILITY?
In technical terms, heart rate variability is the time difference, in milliseconds, between each successive heart beats. Our heart beats aren’t static. Think of the Queen song “We Will Rock You” which is the same beat on and on. Our heart rates are more like “Flight of the Bumblebee.” So from beat to beat to beat, HRV is measuring the change between 2 heart beats as compared to the prior two (see chart below)
HRV AND YOUR OVERAL HEALTH
So what does this all mean? Essentially, a high heart rate variability is a good thing. It means your overall health, heart, stress level is optimal. A low HRV means the opposite.
HRV is like your body’s check engine light, an MRI into your internal health, a measure of your stress level, the overall health and wellbeing of your body. It’s truly an incredible tool if you know how it works, and have knowledge of the technology behind it.
THE TECHNOLOGY BEHIND HEART RATE VARIABILITY
Here’s something you won’t read everywhere. Not all HRV is built the same. There are different ways to acquire HRV and one is more accurate than the rest
RMSSD VS SDNN
There are two types of algorithms devices use to display the end result, your HRV score. SDNN simply records your heart rate (BPM), takes an average throughout the day (usually a 24-hour period) and displays your HRV result in the form of milliseconds. This is done by Apple and Fitbit because it’s easy, but not as accurate as the next method. More on that here.
ECG VS OPTICAL SENSOR (BPM)
No that we’ve talked about the algorithm, let’s talk about the input method. Where is the device acquiring the heart signal from. Almost all companies use the optical sensor because of its versatility and ability to show other information. However, it is much less accurate that an electrocardiogram.
The AIO Sleeve is the only company that extracts HRV value from an ECG / EKG. To get an idea of the difference: a standard optical sensor uses 50 samples per second, whereas ECG uses a minimum of 300 samples per second. This is how often the sensor feeds data to your smartphone. This is quite significant, and is the reason all professionals prefer to work with ECG.
WHAT IS A GOOD HRV?
The only person who knows the answer to this question is you. An 80-year-old with a heart condition and a 28-year-old athlete will have different ideas of what is a good heart rate variability. You will first need to establish your average heart rate variability, or baseline and go from there. Spending a few weeks monitoring your HRV throughout the day will give you a sense of where you’re at. Only then can you break down your daily routine and begin optimizing and increasing your HRV.
HOW TO IMPROVE HEART RATE VARIABLIITY
Many factors will affect your HRV. It takes time to establish what your baseline is, understand your body and begin making the necessary changes. Here are the areas you will want to consider as they all have an affect on your health.
1. Heart Rate Variability and your diet
As mentioned before in the example with the burger, every individual has a unique reaction to different foods even though they aren’t consciously aware. You should check you HRV before and after meals to see how that food affects your body. And it could be different day-to-day depending on how much stress you’ve put your body through that day. So if you eat the same foods every day, and you notice that on Wednesday your HRV dipped significantly after a meal, you should analyze what you did that day and why your body reacted differently. Perhaps you had a fight with a friend, got called in to HR at work or broke up with a significant other. Yes, these things can all contribute to high stress that will inevitably affect everything else you do that day
2. Heart Rate Variability and exercise
Lots of professional sports teams use HRV as a tool to optimize player performance and recovery. But you don’t need to be a pro to use it. You can use it if you’re doing cross fit, yoga, cycling, even walking your dog and doing lawn work. It’s truly a universal tool. When you exercise, your HRV will automatically decrease. This is because working puts your body under a great amount of stress. But that’s ok. This is good stress. However, if that stress from the workout follows you all day long, that’s not good.
HRV is used to gauge how well one recovers from stress, in this case, it’s exercise. If you are fully recovered and your HRV is back to it’s baseline within 1-2 hours, that’s good! It’s a sign of a healthy functioning body that recovers quickly from training. If your HRV stays the same and doesn’t change for hours upon hours, that’s not a good sign. Maybe you went to hard at the gym or on your bike ride. But with HRV, this could have easily been avoided.
Are You Ready?
Another way we use heart rate variability with activity is readiness. If you know you HRV baseline, or your average, and you notice it’s much lower before heading out on your run, you might want to think twice. Exercising and straining your body when HRV is below it’s average definitely does more harm than good. Could be a sign to take the day off or just do light activates. If HRV is well above your average, you’re good to go! But remember, constantly straining your body when you see a low HRV will not only negatively affect a single day, but could ruin an entire week if it becomes a pattern. Again, HRV gives you control over your own body, and destiny. Cool, right?
3. Heart Rate Variability and Sleep?
Ok, so yes, many fitness trackers already come with sleep monitoring that you can view on an app. But it’s only tracking how you move at night to determine whether you are in deep sleep or not. While this is good, it doesn’t give us a complete picture. I mean what good is the Mona Lisa without her head, right?
Measuring HRV before bed and when you wake up gives us true indication of sleep quality and whether one is fully recovered from the day before. If some days are better than others, pay attention to what it is your doing on good sleep days vs. bad ones. Notice your nighttime routine. Are you on your phone a lot? Did you eat before bed? Did you consume alcohol? See what happens to HRV in the morning if you don’t do these things and optimize your sleep.
4. HRV and Stress
Perhaps the most researched topic with respect to heart rate variability is stress and anxiety. Over and over again, clinical research shows a direct correlation between HRV and mental stress. Of course you can’t prevent stress completely, but having visual representation of your stress level is huge. You can identify exactly what things in your life are causing stress and you can look to improve in those moments. Surely you’ve heard people say, “just take a deep breath” when in a tense situation to urge one to calm down. Well, there’s real science behind it.
Deep breathing exercises have been shown to greatly increase heart rate variability, and thus reducing stress. In a case study conducted using the AIO Smart Sleeve, 50 users measured their HRV before a stressful situation and after, while doing deep breathing. There was an average of 2.2 rise in HRV (out of 5 stars), which is quite significant.
The Ice Man
Maybe some of you are familiar with Wim Hof, creator of the Wim Hof breathing method. He is well known for immersing himself into ice baths for a record amount of time, and swimming under a sheet of ice in the arctic while only wearing goggles and a pair of trunks. How can he do that? When your body is exposed to that level of cold, your autonomic nervous system (ANS) is fighting like crazy to stay in balance. Deep breathing counteracts the negative affects on your ANS. Now not everyone can do this. But Hof has such exceptional control of his breathing that it almost completely wipes out the stressors that occur from being under such cold temperatures.
Although it’s not a widely used biomarker at this point in time, one thing is for certain; many researchers and clinical studies validate the use of HRV for every day living. According to World Health Organization (WHO), stress if the health epidemic of the 21st century, and heart rate variability might be the only tool that give us insight into the stress and mental health of an individual. While it’s maybe a couple years away from becoming the gold standard for health assessment, there’s still ways to use it now to improve your life.
In our next blogs we will bring up all the amazing research and show you how you can use it to improve your health.