Activity tracking capabilities of the Fossil Hybrid HR

A member of the subReddit dedicated to the Fossil Hybrid line, Kook_de posted an extremely good review of the Fossil Hybrid HR accuracy for sports and health. So, I asked him permission to post it here to give his work a more permanent place. Here is his review, this is not my work

Thanks a lot Kook_de !

Activity tracking capabilities of the Fossil HR series

Maybe some of you are interested in the tracking capabilities of the Fossil HR series. I compared it against

Amazfit Stratos 2s (now Zepp)

Fitbit Versa 1 and 2

Huawei watch GT

Samsung Galaxy watch active

Additionally, I used an arm strap with optical sensor for monitoring the HR, as well as a chest strap connected to the Stratos 2. I did simple activities like walking, up to workouts as weight lifting.

You can call me crazy – as I did this wearing 4 watches – however here are my results.

1. Steps tracking

First the bad news: pushing a baby stroller – the Fossil hybrid is way off, counting only a couple of hundred steps for 3-4 km. (before the app had GPS)

Do you think the others were better?

Fitbit Versa 1 and 2 both ended with a stride length of 1.99 m. Interestingly enough it was the same for Samsung Galaxy watch active which has a GPS. The worst of the pack was Huawei watch GT with a stride length of 4.99 m.

The best is Amazfit Stratos 2s, which is in leagues of his own in step counting, with a stride length 56 cm. Even if you keep the hands on the stroller handles as soon as you do some steps the cadence and pace immediately go from 0 to the right number. In my experience the Stratos 2s has 1-2% accuracy in step tracking.

Now the good news – in a very controlled setting like an elliptical Fossil counted 4428 steps and Amazfit 4424 steps. But so did also the other devices. 

In a normal walking activity, without the baby stroller all watches came in less than 5-7 % deviation to each other. 

In a normal day, without a walking activity I got the same statistical step distribution through the day from the Fossil as form the Stratos 2s. The step count difference was below 5-10% within these devices. The difference seems rather dependent on the threshold when they start counting the steps. Fossil starts counting immediately you move, while other start doing it after 10-25 steps.

2. GPS tracking

As accurate as your phone is (my phone is not). 

3. HR monitoring

Before going into details, I want to say I am at the 4th Collider – all replaced from various reasons. However, what was constant for me, was the accuracy of the HR sensor and the distribution of the step counting.

The resting HR turned out to be the same for all devices, except Stratos which consistently shows 2 beats more. 

On an elliptical, if you exclude the first couple of minutes when HR frequency increases very fast, all devices performed very well. It was amazing to see exactly the same value displayed on the Stratos 2s connected to the chest strap and on the Versa, Galaxy active and on the phone screen connected to the arm strap. 

The HR values displayed on the Fossil screen were just rubbish. But this is due to the low refresh rate of the screen. At the end of the workout it gave virtually the same HR line, average, max and low HR values, like everything else.

I was also surprised how well Fossil HR keeps up in a weight lifting session. One of my first [post]( was about it. Since then all Fossil HRs I had consistently delivered the same accuracy. But the same goes for Versas und Galaxy Active. For some reasons I can not really follow the optical arm strap is giving very bad readings for weight lifting, while for running and elliptical it performed very well. The optical sensor of the Huawei GT is in a league on his own, as it was the only one on which I could follow the repetitions and rest intervals in a weight training session. It does not have the sharpness of the chest strap, but nevertheless impressive.

4. Sleeping

The Fossil HR is as bad as the Amazfit. It does not reliably detect the bed time, nor accurately determine awake time. I can go to toilet during the night and it will show like sleeping through without being awake. Just bad. However sleep tacking is not important for me.

5. Calories counting

Here is for me the Achilles heel of Fossil HR. 

Many companies will try to convince you Calories counting is complicated and they have the best algorithms. But it is not. Calories is energy – therefore proportional with the oxygen you burn. If you exclude the altitude factor, it can be calculated from the HR, your heart size (body size and resting HR) with different proportionality factors for aerobic and anaerobic regimes. 

Fossil is seriously underestimating the calories. I reported this long time ago to Fossil, and after each app/firmware update I take the Fossil HR watch again to the gym. It did not improve. Here is the last weight training:

Amazfit/Notify and Fitness + chest strap

HR average 127, min 89, max 153, energy 486 Cal (without step synchronization)


HR average 126, min 89, max 151, energy 186 active calories

Runtastic (calculator – weight, seize, age, workout duration and average HR

HR average 126 (like given by Fossil), energy 476 calories burned

The same goes for other activities, except walking. There the calorie count is still lower, but not with a factor of 2 or 3.


The Fossil HR can easily match and keep up in the sensor department with more fitness focused devices. It delivers consistent step tracking and perfect HR tracking. Sleep tracking is not reliable (for me).

Due to the classic look Fossil is easily my favorite. Since its apparition and my first [report](, the app evolved a lot (Fossil if you are reading please bring back the home and sync buttons in the notification area in Android). The design also changed – you can use leather straps for FTW7009 for example. The backlight turns on reliable now, you can adjust the vibration strength, and the buttons… well the buttons… all middle buttons were bad to press except the last one I received. This is very different form the pack – even the middle button hast a quality feel to it.

The reason I stopped using Fossil for workout tracking is the calorie counting. It still remains my daily driver, with very long battery life, comfortable to wear and a very reliable and discreet notification system.  I hope the calorie counting will improve, but for now for workouts I still use something else.