How Does Fitbit Calculate Resting Heart Rate?

Fitbit & Resting Heart Beat…

Fitbit is a well-known American Wireless Wearable manufacturer of top of the class activity trackers. Formed in 2007 Fitbit has remained focused on serving the need of advance tracking, analysis, and computation with regards to body vitality.

Today there are more than 150 million users of the company owning its trackers and smartwatches relying on their capacity to make decisions to better align their lives. However, there is a frequent issue that many faces, and it is not of accuracy but transparency.

Despite the preceding reputation Fitbit seems to have a closed gate. Even when the matter of concern subject can be of something as bodacious as RHR – Resting Heart Rate.

What Even is RHR?

Going by the definition RHR (Resting Heart Rate) is the rate a heart is beating when the person is in a idle state. In other words when they are relaxing, or have just woken up, and there are no stimulus or distractions. While the recorded movement on the scale is zero.

You could also think of as your heart rate when you are chilling without a tension in the world.

And Why is RHR (Resting Heart Rate) Important?

According to the American Heart Association, an RHR (Resting Heart Rate) is a good indicator of a person’s overall fitness and the health of their cardiovascular system. A low number would indicate the presence of healthy practices in place. Usually, athletes or people in their 20s are an occupants of such.

Although some studies have shown RHR being improved after the age of 49, there is conflict within the resolution as to why it is the case. Either way, people in twilight should be extra cautious with their lifestyle. With the global defined average of 60-100 bpm, anything above 85 is a good reason to contact your doctor.

As seen in the graph Women usually have higher RHR than the Men but it is no reason to panic. Neither it’s nature cruelty at play. It’s just down to anatomical differences in heart size and hormone levels. 

Either way, in order to have a healthy RHR number it is suggestable to pursue healthy practices including: sleeping on time, controlling anxiety, engaging in cardio on a frequent basis, and avoiding alcohol.

As evidence clearly suggest that by practicing’s these healthy activities researchers have found a low RHR number in those who actively try to include these in their lifestyle. An ideal 8 hour sleep can lower your RHR by a fine margin and keep you on track for a healthy heart health.

“How Does Fitbit Even Determines RHR?”

There is a reason Fitbit manufacture millions of trackers each year. They are at top of the game. Their trackers have the functions (Advance Sleep Tracking, SPO2 Analysis, and Cardio Burned) that the public demands and needs.

However, as I mentioned above, there is a problem that has been noticed in recent times, and it is particularly concerned with RHR tracking. For reasons unknown an eerie pattern seems to be growing, where results are inconsistent and quite honestly not of use.

And the response from Fitbit to the problem is: Nothing.

Is RHR on Fitbit Even Accurate?

Unlike the clinical tools used in hospital and their ECG (Electrocardiogram) technology to measure the heartbeat using Electrical signals. Fitbit trackers apply a more inferior method of data collection. To record the number of heartbeats Fitbit uses light-sensitive photodiodes (green light) to pass the light through the skin into a vein and then capture the number of pulses in a defined time frame.

Although, in theory, it works and you get a number that’s not way off, if we were to compare this method to the ECG devices, there would be a slight variation within the results. Not to mention since the position of the tracker can influence the result, it is okay to have reservations.

Common Issues

What has been the theme of time and issue for Fitbit users for many years now is the inconsistency that seems to be in Resting Heart ratings. Forcing users to come out and wonder if Fitbit calculation of RHR are even accurate or not.

After all, it has been frequently reported that RHR ratings (measured by Fitbit) are way above the normal Heart Rate. Even when it shouldn’t have been.

I’m finding this very frustrating to be sitting at my desk, and see my HR showing as 74, but my Resting HR being 80. Clearly Fitbit is not using the conventional definition.

Member of Fitbit Community – 2016

Even after 6 years and multiple updates and releases of new models, Fitbit seems to have no answer to it. Apart from the labeled algorithm that calculates the metric, but even it is a secret, and customers are not informed of how it works and why.

Assumed Method

Although, it is hard to tell what is actually happening behind the scenes, Fitbit is reluctant to say anything. From what we have gathered at Chronoat. It appears there is dynamic average that algorithm takes into account to calculate the readings.

For instance, if your readings for Wednesday for the day were totaled to 85 bpm, and then during the night, your Average Sleeping Heart Rate was calculated to be 80 bpm. What seems to happen is then an average would be taken. But it is not going to be confined to those two readings. Data from days before Wednesday would be pulled into questioning too.

Once again, it is just our assumptions, as the emerging pattern seems to correlate with evidence. It is not an official word by Fitbit.

Improvised Suggestions

Given the nature of the Resting Heart Rate metric and its dependence on a temperate environment without stimulus. We feel there are a few additions that Fitbit can integrate within its proprietary method.

For example, Fitbit can use microphones to ensure there are no sounds in the surrounding with a decibel rating of more than a predefined number. They can also work on the improved efficiency of ABC sensors to better calibrate the hint of movement. Likewise, stress measurement and menstrual cycle and pain index tracking integration – if done right – can also bore gratuitous results.

Since it is unknown what happens when Resting Heart Rate is calculated by Fitbit, it would be pretty cool if they are already using one of the above-mentioned suggestions. Although, the results seem not to support the statement.

Fear of Algorithm

Speaking of Algorithms it is understandable why Fitbit moderators on the community platforms have labeled it as a ‘secret sauce.’ Or why Fitbit itself has remained quiet all these years? It is not uncommon to sight in the smart devices/smartwatches world for algorithms to be stolen or used in a manner violating its policy.

Yet I still think a more transparent approach would help put the million minds to ease.

How To Calculate Resting Heart Rate Manually?

It might seem out of scope for our topic concerning how Fitbit calculates resting heartbeat, but I truly believe a more manual approach wouldn’t hurt anyone. Yes, it might not bore 100% accurate results, if your doubt about the activity trackers seems to be taking over, you can always opt for the natural option.

To calculate the Resting Heartbeat by yourself using nothing more than your hand. You should place yourself in a soothing environment. Stay there for 5 minutes, and then do the following in the chronological manner:

• Find your pulse on your wrist first thing in the morning.
• Count the number of beats in 30 seconds.
• Multiply that number by two.

For precision and accuracy, you can repeat it daily to get a good picture of where you stand. After all, it is vital to remain informed about one’s body and what it needs at a given time.

When Does Fitbit Calculate RHR?

So I have seen this question asked many times. Well the simple answer that you need to know is that Fitbit tends to calculate your Resting Heart Rate during the night time.

No one knows the reason why but that’s just how it is and just like everything else that concerns the RHR Fitbit has remained closed lips about it too.

RHR & Fitbit & Confusion

There are two tales to this conundrum.

One is painted with Fitbit’s lack of transparency.

Another is with importance and need of action to keep track of RHR – Resting Heart Rate.

In an ideal world Fitbit would be more open and forthcoming with data computations. Sadly and truly, it isn’t the ideal world, and it never might be.