Fitness Tracker Showdown: Fitbit vs. Apple Watch 🏃🏾

As someone who is enthusiastic about technology, I consider myself an avid collector. I collect various gadgets and components, often from different manufacturers, which led me to purchase numerous fitness tracking devices. I have always been curious about the accuracy of these devices, so I decided to run a detailed analysis on two I keep in constant rotation:  The Apple Watch and Google’s Fitbit Charge.

Since these are my own personal devices, I decided to be the subject of this comparison. I have been using both Fitbit (right wrist) and Apple Watch (left wrist) simultaneously to track my fitness journey. I began recording data on 2023-10-17 and ended on 2024-01-06. The only exercise being tracked was jogging on the treadmill at various speeds.

The general outline of this comparison is as follows:

1. Steps and Cadence Over Time

2. Average and Max Heart Rate

3. Data Consistency, Variability, and Long-term Trends

4. Summary and Conclusion

Question 1: How do the step counts recorded by the two devices compare during jogging?

At the end of the three months, I noticed that Fitbit had 8.9% more steps than Apple Watch which confused me because the only difference is the wrist placement.

Bar Chart of Total Steps Count Comparison

Question 2: Are there consistent differences in step counts, and if so, in which direction (higher or lower)?

Since there was a sizable difference between the devices, I wanted to see the trend over the 90 days.

As you can see, both devices started out little variance but over time you can see Fitbit just take off! There must be more information in the day-to-day step counts. Let us look at the step count distribution.

There we go. For Fitbit, we can see the right skewed distribution which shows several outliers in the maximum range. That helps pinpoint the trend.

Question 3: Does the step cadence (steps per minute) vary between the left and right arm devices?

This chart helps illustrate the few outliers in the minimum range using the Apple Watch. It leads me to think Apple Watch is more conservative with what it considers to be a step than Fitbit.

Now that we understand how the devices manage activity, let us look at how they track my heart rate.

Question 4: How do the maximum heart rates (Max Heart Rate) recorded by the devices compare during workouts?

Even though both devices are being worn simultaneously, Apple Watch’s tracking is more cautious in recording data when compared to Fitbit.

Question 5: Is there a noticeable difference in the average heart rates (Avg Heart Rate) between the left and right arm devices?

Much like when the step count differential became more noticeable over time, so did the average heart rate between devices. This prompted me to check on the consistency of the data recorded.

Question 6: Do both devices consistently record data for the same workouts, or are there any missing or incomplete records?

Well, there is no issue there. Both devices recorded all workouts without corruption in the records.

Question 7: Are there instances where one device shows greater variability in step counts or heart rate measurements compared to the other?

The shorter and wider distribution in the violin plot for the Apple Watch indicates that there is more variability in the step count and heart rate (HR) measurements for Apple devices. This means that for the same person wearing both devices simultaneously, Apple may count steps differently in various situations or conditions. Fitbit, on the other hand, has a narrower distribution, which implies that its step count and HR measurements are more consistent or less variable.

Apple Watch is potentially filtering out movements that Fitbit considers to be activity markers. It is important to know that the exact reasons for the variability could be influenced by each device’s algorithms or sensor sensitivity settings.

With all that said, what can be expected if you choose to wear either device exclusively?

Question 8: Can you identify any long-term trends or patterns in the data that might suggest changes in workout habits or device performance over time?

I have analyzed months of data and my Apple Watch’s steps, and HR measurements are being filtered out when compared to Fitbit.

In conclusion, my fitness tracker comparison has unveiled valuable insights:

If you were to purchase a device from this analysis, the choice is still tough. Whether you lean towards Fitbit's step-count accuracy or Apple Watch's heart rate precision, choose the device that aligns with your fitness goals and preferences.

Thank you for exploring my fitness tracker journey. Remember, the right tracker can make all the difference in your fitness journey. 🏋️

If you have any questions or want to discuss further, feel free to contact me at