More precise heart rate for HIIT

[SwissChris]

The heart rate performs really badly when doing a HIIT or weight workout.
It shows a maximum of 110 bpm for the whole 30 minute workout when in reality I have 160 wnd the pulse is always higher than 140.
Use a machine learning model to improve the heart rate value derived from the sensor.

[YojanaFitbit]

Hi @SwissChris, and thanks for taking the time to share this suggestion about improving accuracy of heart rate for HIIT. We rely on feedback like yours to help us develop products and features that we know our community wants to see. If this suggestion receives votes from other customers and gains popularity, it will be shared internally with various teams at Fitbit. To learn more about how Fitbit decides which suggestions get developed, visit our FAQs.

Watch this space for status updates. In the meantime, try visiting Health & Wellness to talk with other members about all things health and fitness.

[deiG]

This is the fundamental requirement for a smart watch or fitness tracker. Other features are just pluses. 

[charleskn]

This is a problem common to all wrist worn optical heart rate monitors. Check out the reviews on YouTube by The Quantified Scientist, where he measures the accuracy (heart rate, sleep, steps, etc) for various monitors.

I had an AFib incident last year (all tests were good), and I bought a Polar optical arm-band heart rate monitor for my HIIT workouts. I love it because I can either record the workout, or view a heart rate graph live during my workout. I would prefer to not have two devices, but if you watch some of the video reviews you'll see there are any really good options for a wrist worn HR tracker.

[Schulema]

I have tried all the suggestions for getting my Versa 2 to record accurate heart rate while doing of high intensity workout and it is not working.  At the end of the workout the Fitbit says I didn't even elevate my heart rate and it was likely over 140 at peak times.    This is very disappointing and may make me buy another tracker that does not have this problem.

[Sarajane133]

I have had the same problem for months now and I will likely end up buying a different brand of fitness tracker because of it. I did not have this problem last summer and it’s very frustrating. I wonder if it has to do with the change to “zone” heart rate measurements instead of the general activity goal. 

[charleskn]

I use a Charge 4, and find it does fairly well with my heart rate. During steady state aerobic exercise it does quite well. HIIT workouts and jumping rope, etc give it fits, and it tends to lag behind my actual heart rate. As I mentioned in my comment above, this is fairly common for optical monitors worn on the wrist, but some devices are better/worse than others.

One thing I have noticed is that my Charge 4 is sensitive to how snugly I wear it on my wrist, and it seems to like being a bit looser than I think is suggested.

However, as I have said, I use another heart rate monitor for monitoring my heart rate during workouts.

[alib31]

When I am doing interval running my heart rate is at 171 BPM when recovering and 140 when running 😂 this ridiculous. 

Is this a hardware or software issue?

[Sarajane133]

I personally think it’s software. I recently had my Versa 2 replaced because of this issue - I assumed it was hardware. But the replacement watch continues to have this issue. 

I have the same problem. While exercising, my heart rate says “below zones,” and when I recover it peaks. So frustrating. 

Furthermore, when I am boxing (my most intense workouts where my heart rate is well over 170 for majority of time), my watch says my HR constantly jumps up and down, which it obviously doesn’t. I’ve done everything I can to try and fix this problem. I believe it came with the software update early fall last year.  

[Walkabout97]

I also have noticed that the HR Fitbit shoes is too low when doing HIIT type training.  When rowing I use a chest strap to monitor my HR and know that I was well into the cardio zone and in and out of peak zone, yet fitbit showed mostly fat burn and below zone after I logged the workout. Disappointing.

[IslandMe]

So. New here.
I want to buy a fitbit specifically to incorperate HIIT zones.
Unfortunately according to comments, the max heart rate current calculations would lead me into a heart attack. No joke.
I used to be fit. But like millions every day, sh*t happens. Mine started with unexpected injury about 12 years ago. I am now an older, overweight, sedentary partially disabled woman with high blood pressure and borderline diabetic.
Most of my issues stem from limitations on physically doing exercises that burn calories ie. running, sit ups, jumping etc. I just couldnt do more to burn calories. Restricting calories only put my body into starvation mode and guess what? I actually modestly over time gained weight and became weaker and listless. Geez.
However, after a desperate search, HIIT offers hope!
Turns out, walking uphill in my current state would get my heart rate to max! Then I thought Id walk downhill or in spot to get to the rest phase heart rate and resume uphill again for next interval. And so on until my total minutes in my HIIT outine was up!
I was excited. I thought of other activities that are hard but safe for me to do that would achoeve the same HIIT targets. Finally a way to burn calories and move!
Whats easy for most of you is a HIIT activity for me. In time, I had hoped to regain muscle, coordination and improve oxygen so then I would try swimming etc to regain new HIIT zones as my cardiovascular health improved, rendering my initial activities insifficient to maintain the in new HIIT zone.
But.... this is the 2 areas, 1 being discussed, that FITBIT seems to fall down on.
1. Max heart rate for accuracy needs to include resting heart rate formula mentioned above PLUS another modifier for sex. Im female. A similar aged man in my situation fairs better often cardio wise.
2. There should be a feature that over rides your presets in the fitbit app so I can enter my own max heart rate or you can offer a choice of formulas to set max heart rate, my weight, my starting activiyy level, my BMI, my blood pressure... that will then be the basis for all measures your fitbit can do like calories burned etc.
Id like that these features prompt me to update my baseline as my body changes to keep the counts as current and accurate as possible. Bi monthly or monthly.
Im going to end with a quote from a site that just happens to sum the heart rate matter well. Ive read the peer reviewed studies she bases her findings on and in her article, refers to.
*I want to buy your product but as it is, it is useless. It might even kill me if I didnt understand that the default formula fitbit targets are just too high to reach and maintain.
3. Ok I have a 3erd request. Id like specifically a customiseable, saveable HIIT activity page. No need for the exercise to be included though a title and description area to differentiate my HIIT routines and their settings.
Just a timer of sorts, set max heart rate target ( based on the updated formulas below) , then the % of effort... some say the 85% but I might choose 70% of max HR to start out on. Same for Min heart rate. Then customiseable timers with repititions... 30 seconds warm up once, 30 seconds max hr at 85%, followed by 45 seconds lowering heart rate to 65%..repeat 15x followed by warm down walk and stretch 5 minutes. Total time shows 24.5 minutes. A simple page by which I can set goals and have alerts sound for guidance as I transition between heart states as picked up by fitbit. Itd be interesting if time feature also showed actual time by my heart rate, it took to get from high to low next to each set. It may be my goal is something in reality I have to work towards so alerts should be able to be set to go off either based on stated routine goal or for the 'real time' monitored heart rate. Itd be nice to see expectations vs actual effort. It might take extra time to get my heart rate down. So a toggle button to set between GOAL or TARGET would moderatw the alerts.. in Goal itd switch by preset times, in Target the alerts would only activate once max/min HR was met, noting real time taken. Both have value. An eleate athelete usinv HIIT for general fitness maintenance would prefer using the GOAL alerts, I the Target alerts, but both of us would still like yo see real time it took in each set. For them, confirmation of executing routine as expected. For both of us, a goal standard to maintain or in my case live up to .
If you fix this, shout it to the rafters. There are millions of new users like me that would use your fitbit to regain health and mobility. This alone should motivate your flexability to solve this for us and also directly venifit ALL your existing users. Asthmatics, low back injured, bad hips/knees are all common issues that HIIT can still work for 'IF' there is an accurate and evolving max/min Heart rate calculated by your app. Thankyou for listening.
Comparing Formula Results:
Take a look at how target heart rate zones would be different using the female-specific maximum heart rate formula. For example, here are the results for a 49-year-old woman with a resting heart rate (RHR) of 65: Traditional formulas (men and women):
Fox formula (men and women): 220 - 49 = 171 beats per minute MHR
Tanaka formula (men and women): 206.9 - (0.67 * 49) = 174 beats per minute MHR
New formula (women only): Gulati formula (women only): 206 - (0.88 * 49) = 163 beats per minute MHR
There are also other factors. If you derive target heart zones using the Karvonen formula (which accounts for resting heart rate) you'll get a different result.3 For a suggested exercise zone between 65% and 85% maximum, you can see how different the ranges are:
Fox formula: 133 to 155 beats per minute
Tanaka formula: 136 to 158 beats per minute
Gulati formula: 129 to 148 beats per minute
The research findings suggest that women might be struggling to reach a certain exercise intensity. Even if she is fit, a woman may find it difficult to achieve a maximum heart rate that has been overestimated. The Bottom Line Unless you're an elite athlete or a cardiac patient, you might not need to pinpoint your target heart rate when you exercise—following the scale of perceived exertion might be all you need. If you are a woman and you want to get the best information about your target heart rate, use the Gulati formula combined with the Karvonen formula.
https://www.verywellfit.com/womens-heart-rate-response-exercise-3976885

[fonnesbeck]

This heart rate issue is *still broken* on the Pixel Watch. There is not really any point of tracking a HIIT workout if the heart rate is inaccurate. Mine shows resting heart rate throughout the workout. The monitor works fine if I choose Bootcamp, but for HIIT it is completely broken. This should be a trivial fix. Can we get someone from Fitbit to comment on the status?

[charleskn]

There are some old comments here, so I will mention about those first. Keep in mind these are little computers that are taught how to interpret signals from the accelerometer and the HR sensor. On the wrist, the optical HR sensors get a fairly weak signal, so anything that flexes the wrist/muscles will add noise to the signal the watch is trying to interpret.

• Pretty much ANY wrist-worn optical heart rate tracker will have a difficult time with true HIIT workouts. The sample rates, and everything else means that the measured HR, shown on the device, are always behind your true HR.
• Any activity which impacts the wrist, causes wrist flexion or vibrates the wrist will affect the accuracy of the reading (boxing, pushups, rowing, mowing the lawn (less an issue for HR), etc)

IMO, taking a Fitbit to a HIT workout is like trying to use a VW Beetle to get your large famiy to the movies. It might get you there, but it is probably not quite the correct tool.

For @IslandMe - Congratulations! I was in your place (I'm over 60, type-II diabetic, etc), and HIIT really helped me get fit during the initial Covid lock-down. It's great that you're looking at ways to safely get your heart rate elevated. Search the web, and I am sure you can find lots of ideas. Now for some specific comments:

• I know it feels like you'd die, but your max heart rate is really your max heart rate. It will change some with changes in weight & fitness, but (at least) the NIH says those differences are negligible. Our cardio-vascular system is wonderfully self-limiting 🙂
• You can set your own max heart rate and heart rate zones in the Fitbit settings, under your personal info. I have done this, but I dont think it affects things too much. 
• Your unlikely to get a specific page just for HIIT activity, but you can certainly make that suggestion in the suggestions forum. What you can do is name all your HIIT workouts with specific names (e.g. Walking HIIT, Cycling HIIT, Rowing HIIT, etc)
• Unfortunately (there are suggestions for this), you can't access the timers from the exercise apps. There is an interval exercise, and you can modify the move/rest periods, and the number of intervals, in the device settings. I found that I liked using an interval timer on my smartphone, but I was doing stationary HIIT with pushups, jumprope, etc.
• Take your time, though, and don't jump right into HIIT. Spend a month working on increasing the intensity of your walks to give your body/muscles a chance to get used to the new work. It will be less discouraging when you start to ramp into a HIIT style workout. Over time, as your fitness increases, and you gain confidence, you can also cycle through different exercises as part of your intervals.

With any of these wish list items, you can always make suggestions on the suggestion board.

https://blog.fitbit.com/max-heart-rate/

Good luck!

[SwissChris]

If it's not possible to improve the sensors or the software, could you please integrate the pairing to chest belts?