What You Don’t Know About Fitness Trackers

Tracking your steps, heart rate and calories burned seems like a great idea… but is it really?

It seems like just about everyone wears a fitness tracker nowadays. Between Apple Watches and Fitbits, using a fitness tracker to monitor aspects of your health and fitness has become part of the daily routine for many. 

But is what being tracked even as accurate as we believe it to be? We’ve got the scoop, so keep on reading.

Are the amount of calories burned accurate? 

Long story short… no. 

Fitness trackers are shown to be 20 - 93% inaccurate when measuring the estimated calories burned.

This is because there are a range of factors that are not taken into account when giving your estimate. 

For example, depending on your height and weight, you could burn anywhere between 400 - 800 calories from walking 10,000 steps. This is a BIG difference! 

So do not take the amount of calories burned to be 100% true… instead use it as a guide or extremely rough estimation. 

Is the heart rate estimate accurate?

The heart rate estimate may be one of the most accurate features of a fitness tracker. 

It has been shown that fitness trackers ARE accurate at measuring heart rate.

So what does this mean for you? Use your heart rate estimate to assess the intensity of your workout. The higher your heart rate, the harder your body is working during exercise.

Keep in mind that over time, as you get fitter, your heart rate may not get as high as it used to - and that’s a good thing. That means your fitness is improving and your heart doesn't need to work as hard to sustain exercise 👏

Is my step count correct?

Generally, fitness trackers are quite accurate when it comes to step count, however, your step count may be under or overestimated depending on the situation.

When walking at slower speeds, fitness trackers tend to overestimate your step count. Walking at faster speeds tends to underestimate step count. 

So keep this in mind next time you check your step count - and instead, use it as a rough guide to track your daily movement.

What about tracking sleep? 

Fitness trackers are not as accurate as you may think when it comes to tracking your sleep. 

Total sleep time and sleep efficiency tends to be overestimated. The amount of times you wake up each night also tends to be underestimated as fitness trackers aren’t super reliable in detecting nighttime awakenings. 

Instead of relying on the data from your fitness tracker, you could do a morning reflection about how you felt your sleep was. Rate your own quality of sleep and how you feel as soon as you wake up. This may be a more useful guide to tracking your sleep.

So should you use a fitness tracker?

If fitness trackers help keep you motivated and encourage healthy behaviours, then sure!

But if you find yourself becoming obsessive about the numbers, then girl, it’s time to ditch your fitness tracker. 

The #1 thing to remember is that the numbers are NOT fully accurate. So don’t take the numbers to heart and remember - what matters in the long run is that you FEEL your best and are working towards your fitty goals in a healthy way. 

Be sure to follow @wbkfit on IG for more helpful tips and content! 💗 

WBK FIT Squad xx 

References 

1. Shcherbina et al. (2017). Accuracy in wrist-worn, sensor-based measurements of heart rate and energy expenditure in a diverse cohort. Journal of Personalized Medicine, 7(2), https://doi.org/10.3390/jpm7020003

2. Evenson, K., Goto, M., & Furberg, R. (2015). Systematic review of the validity and reliability of consumer-wearable activity trackers. International Journal of Behavioral Nutrition and Physical Activity, 12, https://doi.org/10.1186/s12966-015-0314-1 

3. Crouter et al. (2003). Validity of 10 electronic pedometers for measuring steps, distance, and energy cost. Medicine & Science in Sports & Exercise, 35(8), https://doi.org/10.1249/01.MSS.0000078932.61440.A2