Fitness trackers accurately measure heart rate but not calories burned


A Stanford inquiry into the accuracy of seven wristband activity monitors showed that six out of seven devices measured heart rate within 5 percent. None, however, measured energy expenditure well…

…“People are basing life decisions on the data provided by these devices,” said Euan Ashley, DPhil, FRCP, professor of cardiovascular medicine, of genetics and of biomedical data science at Stanford. But consumer devices aren’t held to the same standards as medical-grade devices, and it’s hard for doctors to know what to make of heart-rate data and other data from a patient’s wearable device, he said… More at Stanford Medicine.

Seems that we have a long way to go in terms of how these devices can measure individuals.

I know a few people who wear an Apple Watch and the calories burned is markedly different between each person. It should of course be this way, but at times the differences are so different that they make little sense. At least the Apple Watch is the best for heart rate sensing I guess.

Categories: Tech News

2 replies

  1. Heart rate, actually heart beat, is measured directly. Calories burned are estimated based on type and duration of exercise. Hopefully they take heart rate into consideration as well. In the lab, to quote the article, “Metabolic rate was estimated with an instrument for measuring the oxygen and carbon dioxide in breath — a good proxy for metabolism and energy expenditure.” And even with those measurements, the metabolic rate, or calories burned, is estimated. Until smartwatches can measure respiration and oxygen content directly, calories burned data isn’t going to be very accurate.

  2. My general rule is that when it comes to weight loss and keeping forget, ignore calories burned. Unless you’re a constant marathoner and/or have absolute OCD about calories consumed along with the willpower of a saint, use your Base Metabolic Rate as the basis for what you should be eating- any extra calories burnt are just a bonus, along with the general cardio-vascular boost you enjoy.

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