Everything You Need To Know About Heart Rate Variability Testing

When it comes to tracking the health of your nervous system, your ability to bounce back from a training session, and even your mental, spiritual and emotional stability, nothing is as effective as heart rate variability (HRV) tracking.

In the article “What To Do When You're Overtrained“, I explain how I personally use heart rate variability testing to identify whether or not I've pushed myself too hard (and exactly how I dig myself out of the overtraining hole if my numbers are not ideal).

And recently, in the podcast episode “What Is The Best Way To Track Your Heart Rate Variability“, I explain that the system I currently use is the SweetBeat HRV App for real time monitoring of heart rate variability using a smartphone app and a compatible heart rate chest strap.

Ronda CollierBut to get the most out of this type of self-quantification, you really need to geek out on this and learn everything you need to know about heart rate variability testing and analysis.

So in today's audio interview, I speak with Ronda Collier (pictured right), B.S.E.E., M.A. Psychology, who has more than 25 years of experience in high technology product development with a proven track record of delivering leading edge consumer electronic products.

Ronda has spent the last 3 years as an independent scholar researching non-invasive health monitoring techniques to improve overall personal well being, and this research led to the founding of SweetWater Health.

Want to find out exactly what I ask Ronda, listen to the interview, get some screenshots of what heart rate variability analysis looks like, and learn exactly what you need to get started?

Then keep reading…

During the interview above, I ask Ronda:

-What is heart rate variability (and don't spare the nitty-gritty details!)?

-When it comes to analyzing your numbers, what is the significance of RR, LF, HF and rMSSD?

-Can HRV be used to predict overtraining, inadequate recovery, “chances” of getting sick, etc.?

-Do different HRV testing systems use different algorithm to give you your HRV score?

-How can HRV be used to detect food sensitivities?

-And much more!

For SweetBeat HRV monitoring using the methods Ronda and I describe,  you need:

-The SweetBeat phone app:  + a wireless Polar H7 chest strap:


The SweetBeat phone app:  + a regular chest strap: + a “Wahoo” wireless adapter for your phone:

Regarding my own personal HRV, which I sent to Ronda for 30 days to analyze, she said:

“I ran your SweetBeat sessions through some of our more advanced algorithms to get an even more precise view of your nervous system.  Your numbers were great.  You are truly a personal testament to your work!”

The following are the total averages of your sessions.  I frequently see you in the 8,000 – 12,000 range for low frequency (LF) and high frequency (HF). Your HRV is normally 100, the highest possible score.”

It's good to know that I'm doing something right!

In a future episode, I'm going to share with you some of the personal meditation and recovery techniques I use to enhance my HRV score, but for now, this article would be a good place for you start.

Finally, the following charts (click to enlarge) are an additional analysis on my personal HRV and a photo of how the SweetBeat system works. Here is also a very helpful .pdf from Quantified Self if you want to dig into the nitty-gritty science a bit more.

heart rate variability data

Questions, comments or feedback on heart rate variability testing? Leave your thoughts below!

106 thoughts on “Everything You Need To Know About Heart Rate Variability Testing

  1. Hi Ben–

    Love the podcast! I often hear folks online say that HRV only indicates recovery and overtraining well for endurance athletes, but not strength or bodybuilding athletes (since the CV system isn’t as involved). Is there any truth to this rumor?




  2. Hi Ben,

    I downloaded the app and have been using it for a while but it doesn’t measure my skin temperature, calories and steps, as shown in the sample pic. My chest strap is Polar H7 one of the recommended ones.What should I do?

    Thank you!

    1. Those are not variables that you need to measure actually. The chest strap will measure them while you are lying in bed but they are variables that you can actually ignore. You only should be taking it for five minutes lying down in the morning anyways…

  3. Ben or Rhonda,

    Any comments about PVC/PACs and HRV? Is it possible that pvc/pac are just very clear signs that your HRV is great?

  4. Hi Ben,

    I downloaded your Nature Beats app, and it won’t find my Garmin heart rate monitor chest strap even though the wrist heart rate monitor picks up the signal from the strap. Any thoughts on how to get the Nature Beats app to pick up the signal from the chest strap? Thanks! John

  5. Hi Ben, I understand that not all heart rate straps provide the accuracy for HRV calculations. The Polar H7 is recommended. I’m looking at the 4iiii’s viiiiva ant+ and bluetooth since its a dual channel transmitter. Do you know if its accurate for HRV?


  6. Hi Ben, thanks for your podcast – its been huge in helping me bridge the vast chasm between yoga and fitness/biohacking. Is there a wired (non-blue tooth) sensor that can pair well with this app or Naturebeat?

  7. Hi Ben,

    I know you personally shoot for an HRV of 90 or above to dictate whether you train or not. Do you recommend that number to your clients as well? I can’t get mine above 85 and based off my baseline, sweetbeat still tells me I’m good to go for a training session. With that said my Lf/HF ratios are not always balanced, I’m typically more sympathetic dominant yet sweetbeat still tells me that my HRV is recovered and that its ok to train. What are your thoughts on that? If my personal HRV is ok, but my Lf/HF ratios are unbalanced should I train. Thanks Ben

  8. I am noticing big differences between Sweetbeat readings and the EliteHRV app. I wonder why? Use the H7 Polar to iPhone.

    1. Alan, from what I can see on the surface, Elite HRV does not properly filter its raw data. Sweetbeat is clinical grade and adhere to the EuropeanSociety of Cardiology and the North American Society of Pacing and Electrophysiology. They have defined specifications pertaining to filtering.

      With that being said, there is no single “HRV” number. LF, HF, rMSSD, SDNN, etc are all HRV. What the industry has done is take one of those numbers. For example SweetWater uses rMSSD and has a nice little algorithm to calculate the log and make it a readable number from 0-100 for the consumer. Elite HRV does the same, but who knows what their algorithm looks like. So everyone’s HRV number is going to be of their own making and proprietary.

  9. Still trying to find an app or adaptor that allows me to use my Garmin HRM-Run with an iPhone 6/ios8. Up above a Wahoo adaptor was mentioned but I clicked the link and can’t find such an item. I gather DigiFit remains the best option for this hardware?


    1. You're probably better off getting the 60beat BLUE Heart Rate Monitor, only $35 on Amazon and tested to be HRV capable.

      By the way there is a nice new free iPhone app called "Elite HRV" that I've been using regularly.

  10. provides similar functionality for free and it allows r-r interval export if you want to do super geek analysis in kubios or similar software. Good luck

  11. Hey Ben,

    I purchased the ithlete app in January because I noticed I wasn’t recovering my workouts (GST, Sprinting, Olympic lifting) and felt like I was getting weaker and weaker 6 months prior. my sleep was becoming very disturbed and I noticed I was becoming out of breath doing simple things.

    Long story short I found out I had Lyme disease in March (currently being treated with antibiotics and my sleep is finally returning to normal). That being said my HRV rarely goes the 60’s. Its hard for me to not stay active (I pretty much continued to workout through the whole thing even though sometimes i feel terrible) but I’m pretty sure the Lyme has effected my CNS.

    Just wondering if you have worked with or talked to. any athletes who have been in similar situations and if they did something that improved their situation.

    I’m currently using a cyclic ketogenic diet (carb up meal 1-2 times a week usually around 150 g), taking lots of B12, magnesium, rhodiola rosea, ashwagandha and a couple other natural supplements to help.

    Anyways, sorry for the long question. I know your a busy guy but I know your extremely knowledgeable and I’m just looking for any pointers or advice I can get right now to help me get back on track.

    Thanks Ben!


    1. Yes, I've definitely done consults with folks before to talk about this situation. There are some really good books out there on Lyme management too. Look up Dr. Nicola McFadzean, a naturopathic doctor, and the author of The Lyme Diet. I'd also be happy to help you out via a personal one-on-one consult. Can you please check… and then let me know if you have any questions? We can do 20 or 60 minutes, whichever you'd prefer.

      1. Thanks for the quick response Ben I really appreciate it. I'll have to check out that link you sent me when I get home from work later tonight.

        P.S. that podcast you did with Robb Wolf was good stuff..very informative and interesting!


  12. Great, just got the app and it's really well put together. I'm not sure the data exported from the website can be read by Kubios though? I'll have to try.

      1. Well I tried and no go, it's a .vcs file, a "calendar" file apparently, and it contains no r-r data unfortunately…Well I suppose that if need be it's easy to run HRV+ for a minute after Sweebeat and export the raw data.

        1. Rado just wrote me and said "Hi Ben,

          "I've been trying to sign in so I can respond to that user asking about the RR Intervals for Kubios. This is a new feature we are working on for our newest app that will come out in the next month. If you have a moment, feel free to let him know that!


          Rado Stoycheva"

          1. Good to hear, thanks! I hope existing users will get access to this feature, the "newest app" vs "latest update" worries me a bit though…

  13. A bit late to the party, but excellent stuff, thanks for sharing! I was already using the 60beat strap with the free HRV+ iPhone app but it doesn't show LF/HF (that I can get via export+Kubios but that's a bit of a hassle) so I'll probably go for Sweetbeat especially since they've dropped the price from $4.99 to$1.99 (limited time?).

    Smartbeat looks interesting too but it does seem to have been abandoned (no mention on their website) so the addition of Bluetooth LE support is very unlikely unfortunately…

  14. This insight will definitely help with my analysis for my Physical Therapy class! I'm supposed to analyze the impacts that autonomic nervous system imbalances have on the human body and the variety of ANS testing tools available. Based on my research so far I've discovered that this system plays a very critical role in managing our daily bodily functions such as heart rate, and blood pressure. I've also learned about the tilt table test which is also non-invasive. I can't wait to graduate and become a physical therapist, this information is so fascinating!

  15. I just bought the Sweetbeat app and have two HR monitors, my Garmin does not work, How about the Suunto CY0757? With Iphone 4.

    Definitely don't need one more in my drawer. Any suggestions?

  16. New(ish) Product: Ant+/BT HR monitor strap that (now) works with SweetBeat.

    So, starting like last week (10 April 2013), the latest shipping Viiiiva HR monitor bands by Canadian company 4iiii support HRV data with SweetBeat. Prior bands from them did not support the BT R-R data, but now they do.

    Why this is important: I use Garmin Ant+ stuff. I have an iPhone. I travel a lot. I do NOT want to buy a separate BT HR strap, or hardware dongle for my phone; I just don't want to carry more crap. This strap sends Ant+ data to my Garmin watch, but can ALSO function by doing BT 4.0 with the iPhone and works with SweetBeat. I get both in one strap. The added benefit that it (the HR monitor strap) can also take in Ant+ data from your footpod/power meter/whatever and port that via BT 4.0 to your iPhone may be something you bikers out there will like too; for me as a runner, I won't use it. But it's pretty cool!

    Ben, you should make an announcement, or update your summary here to note all this. This is definitely the way to go (and no, I don't work for or even know the 4iiii people).

  17. I was a beta tester for the tinke and found it to be horrendously inaccurate. If it can't deliver an accurate HR, it sure as heck can't be giving an accurate HRV. Garbage in/garbage out with tinke.

    1. Ken, Tinke has instilled numerous changes since the beta testing phase last year. Check this out:2 of our recent reviews are:

  18. Dear Ben,

    find this epsiode very beneficial.

    After this i did a Professional HRV test and got very poor results (believe largely due to workrelated stress).

    Can you give recommendation how to improve the HRV immdiately?

    Many thanks,

  19. Hi, Ben,
    I have an old emwave that a friend long-term loaned to me. She said that she thinks the new one isn't that different, maybe the ability to track progress on a computer, but I don't feel I need that. Since I already have a unit, would you recommend sticking to the emwave? Or do you like sweetbeat so much more? My main goal is to learn to relax. Secondary is tracking effects of training.


  20. Ben,

    Could you possibly provide a chart or something that summarizes Ronda's definitions of the different combinations of RR, HF, LF, etc and what they might indicate?

    Also, When you take your morning HRV reading, do you take the number off the front or the Average number given in the history?


  21. Hey Ben, Thanks for asking about the CNS stimulating foods and there effect on Dr. Coca's pulse test! That is some cool stuff

  22. No, it doesn't. I, also, have iThlete but their dongle isn't recognized by SweetBeat. I also have Runtastic dongle, which works fine with Polar's chest strap and SweetBeat. I guess it's pretty equivalent to 60 beat.

    1. Unfortunately Garmin does not have an open API for their ANT+ receiver dongle and thus SweetBeat does not support this. The only 3rd party that was able to support the Garmin was Digifit. SweetBeat supports the Wahoo Fisica Key ANT+ receiver dongle.

  23. Ben, the apps sounds real interesting, but my question is what do you do when you daily HRV? If I get a number such as 83, does it mean go out hard, take it easy or rest? Or is there something that is built in the app to help out?

    Your article about over-training indicated dropping HRV, but did not share your numbers as an example.


  24. Great interview! I had been hoping for more on this for awhile. I have been using the iThlete for over a year now after reading about it in Maffetone's book. It has been very helpful. Does anyone know if the iThlete dongle will work with Sweetbeat?

  25. Ben,
    got a chest strap and the SweetBeat. Have you found any written info that help explains the 'geek' numbers?
    What they mean? How they change? What is good/bad?

  26. ben, i bought the emwave a while back. wish i had waited and just got an app for the ipad. can you get same info for emwave? frustrating after listening to the podcast that i have no idea what the data i am getting with this thing means (and god knows how much more i paid)!

    i think i remember you saying heartmath was good company and more focused on "training" HRV. i did not hear you talking about that as much as the data in this pod. does sweet beat do the same sort of thing or is emwave different in this regard?

    1. The emWave is still better if you're looking for a software program that gives you biofeedback/neurofeedback and trains you how to relax properly and enter into a state of coherence. The education component from heart math is also way better.But these apps/smaller devices are better for portability and fast ease of use, tracking athletes, etc.

      1. also, is there a way to track the HRV on emwave or emwave2 as Sweetbeat ? Maybe NOT as easy as using Sweetbeat BUT still track information for performance and sports recovery.

  27. I have been running marathons and ultra events for the past couple years. Dearing the end of the event and after the event I do stupid stuff or I’m not thinking very clear. I bet my HRV is not good. My natural pathic doctor Is always saying I am low on and vitamin B12 ,adrenals and I need CoQ10. Could it be that running marathons and ultra events are bad for us? I wonder how many of them I should run a year if any at all?

  28. Ben, excellent podcast. Can you explain why a lot of time variability between heart beats is good. To me this is counter-intuitive. I understand the sympathetic and parasympathetic systems "compete" to affect this time variability, but you would think that a balanced state for the body would be characterized by something which is constant/uniform, and that something random/haphazard would characterize a state of flux i.e. fatigue or such like, in the body. Happy to take people's word for it but just wondered WHY?

      1. @PaulG- High variability is an indication of ANS flexibility and is indicative of a nervous system that can respond and recover from a wide range of physical and psychological events. Think of the nervous system as a rubber band. A new rubber band can stretch in many directions and return to it's normal shape while an old rubber band does not stretch well and may not return to it's original (stiff and cracked) shape.

  29. HI Ben and others! This is great stuff! Disclaimer up front – I work for Omegawave. I would like to mention that while HRV is a great tool, it doesn't tell you the whole story. It's just one side of the story. Identifying in which stage of recovery you are and how your development is going is the other side.

    PLUG – If you use Omegawave, you will get personalised heart rate zones for YOUR exercises, based on YOUR Anaerobic threshold, not some formula. You also get information on your aerobic readiness, which essentially tells you how fit you are and how long you can go. This also correlates to the line when you cross over from aerobic to anaerobic and the grey zone in between.

    Ben – I would appreciate your feedback and hopefully everything is working out great!

      1. Hi, Ben,

        Don't know if you saw the recent WSJ article mentioning the Omegawave. Does the Omegawave do something beyond HRV? I saw that they say they use 'ECG waves' but don't know how this is better or different from their competitors.

        1. I'm currently testing OmegaWave. So far, SweetBeat has more options and is more comprehensive. I'm not certain about the difference in ECG Waves with SweetBeat vs. OmegaWave though. I'll find out.

          1. I just got the OmegaWave and am testing that out. I guess the difference would be that the OmegaWave has sensors on the sides, in addition to the normal piece of hardware on the center of the chest. It'd be interesting to hear more about how they calculate 'readiness.' Their site is somewhat limited, so I don't know if they don't discuss that because it's top secret or because they haven't gotten around yet to providing more complete documentation.

          2. Hi Kathy, just curious if u are satisfied with the omegawave and the info it provides? Thanks, marcus

  30. Awesome topic again Ben. During the interview your guest mentioned that HRV tracking could show the cross over point from aerobic to anaerobic, which I'm assuming would be great for those looking at using accurate numbers for the Maffetone method. It sounds like it is not available at this point but was there any indication off air if that is something they are looking at implementing in the app?

    Thanks, and great show again.

    1. They have a new version "Wahoo Fitness Blue HR Heart Rate Strap" that works with the iPhone 5. It is more expensive but doesn't require the Ant+ adapter.

  31. As Ronda mentioned the Sweetbeat number is just a scale. I think you would need the underlying details from ithlete to do an apples to apples comparison.

    I used ithlete for a while but found it to be tempermental no matter which heart rate strap I used. I find Sweetbeat and other apps such as Azimo's Stress Check and Stress Doctor to be more reliable .

    1. How does Stress Doctor differ from Stress Check and how accurate are these apps given that most others use an HRM for the reading as opposed to the finger over camera method.


  32. I downloaded the app to my iPad but I need to get a heart rate strap if I buy a garmin, polar will they be compatable with my iPad app? Great info by the way. Cheers Alan

  33. She lost me when she called it the vagal nerve. It’s the vagus nerve and vagal refers to a maneuver to drop your blood pressure… Such as bearing down. :(

  34. Hi all,

    I've found this morning a nice iPhone app giving me a little more control on my HRV data: Smartbeat ( If you want some data to dig into you may want to check this app out.

    I'd like to correlate HRV and track data and so I'd like to know whether anybody experienced ever problems using multiple apps using the Wahoo Fisica adapter at the same time, e.g. Endomondo and Sweetbeat?


    1. +1 for Smartbeat. I like Sweetbeat for a quick check-in on my stress level but Smartbeat's customizable orthostatic test is fantastic. What's more, it quickly gives you a highly useful number (LF/HF ratio) that I think is much more accurate for tracking overall stress and recovery than HRV alone. This article gives a good description of how to do it (

  35. Ben and others,

    What's the best alternative to Sweetbeat for those of us with Android phones? I'm not an intense athlete although I do like to keep fit with weight lifting and kettlebell swinging among other things. I'm mainly interested in using hrv to help monitor and manage stress and food sensitivities.


  36. I bought the app direct after listening to the interview. What I didn't realize that lot of the fancier stuff (LF, HF power and relation) was not available :-(
    I've been using the iThlete app + hardware for HRV monitoring with good results. I'm going to run these two parallel for a while to see which gives me more. Today I did the baseline measurement with SweetBeat and a regular measurement with iThlete, and the difference was quite big! According to iThlete my HRV was 69, and SweetBeat says 83. What to make of that? Maybe the iThlete is more accurate at the moment since I've been using it for over a month now, whereas the SweetBeat only has my baseline recording? I do like the idea of getting a stress reading, too, instead of just HRV. Do you think that would correlate highly with cortisol levels?

    BTW, I used my Polar RCX5 chest strap and a Runtastic dongle, and these work fine with the SweetBeat.

    Enjoy your podcasts, keep it up!

      1. I just logged in to make an update that I had found the "geek" mode when I saw your reply, thanks. And I had listened the episode you referred to but couldn't remember the details. I did my second measurement this morning, and the difference b/w iThlete and SweetBeat was much smaller now, insignificant. But as I have an academic background, I'm now more interested in the geeky additional info that SweetBeat has over iThlete.

        Thanks again!

      2. I've found the "geek" button for a current session, but is there any chance to see your LF, HF, rMSSD for your history files? I can't find them either on the Iphone nor on MySweetbeat. THX

      3. I couldn’t get through all that unrelated nonsense, can you please just write the answer in brief? I too am wondering why Elite HRV has a different reading than HRV Lite and Pulsometer. And it has nothing to do with how long I’ve been using them, because I’ve only been using them for one day.

  37. This app is amazing!!!! Would love one. Us poor students will have to just make sure we don’t overtrain an use built in hrv awareness ;)

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