Find Out What The Data From Your Smartwatch Actually Means

How do smartwatches measure calorie burn?

According to a 2019 study in the International Journal of Environmental Research and Public Health, the most accurate way to determine the number of calories burned is to measure the difference between oxygen and carbon dioxide levels in each breath. Naturally, smartwatches can’t do this, so they instead measure a user’s heart rate against data they provide, such as age, weight, height, gender, and usual levels of physical activity.

man arm wearing Apple watch
Mateo Abrahan/unsplash
Mateo Abrahan/unsplash

But while some devices get closer to the truth than others, none of them can be as accurate as the unwieldy and expensive tech that uses breaths to measure this.