Can You Trust Your Fitness Device?

Technology is very cool and has amazing applications as it relates to our health and fitness. Fitbits and other devices are used to measure heart rate, steps, calorie expenditure, and other biometrics. Plus, they are extremely popular. But can you trust them? How accurate are they?

There are several studies out recently, and they all seem to agree. They are generally pretty accurate when used to measure heart rate and steps or distance. Most popular devices such as the Fitbit and the Apple Watch were within about 5% of heart rate and distance. That is pretty good!

Calorie expenditure is another matter. In various studies, it seems they are often as much as 30% off and some even much more. There are several reasons for this, but ultimately you should not rely on them to get an accurate reading of your calorie expenditures. There are many resources you can use along with your device to help get an idea or an estimate of your calorie burn.

If you simply do a search, you will find programs that will help you. If you want to get as good a number as you can, find an online program and use it and your device together. It should get you quite close and give you a general idea about how many calories you are burning.

Counting calories can be critical when trying to lose weight. You will lose weight when you burn up more calories than you consume. If you read about calories and weight loss, it is generally reported that one pound of fat is equal to 3,500 calories. In order to lose one pound then, you would want to burn up or decrease your input by 3,500 calories.

The problem with the 3,500-calorie number is that it is just way more complicated than that! If we are in a controlled setting (such as a laboratory), this number is probably really accurate. But counting calories or estimating how many you consume is at best an educated guess. Even the professionals are off as much as 25% and our devices may be off as much as 30%!

I believe it is still a good idea to try to understand how many calories you are consuming and/or burning up, but it is a guessing game. Hopefully, you can get to within about 10% to 20% with some education and help from your device. Chances are your device is really close on the distance and heart rate, but not so much on calories.

Do you have a Fitbit or Apple Watch? Do you think they’re accurate?

Wishing You an Amazing Life,

Dr. Curtis Brown