What does it mean to be healthy? Exercise and eating right. Most would rattle these off as if theyโre the answer to a third-grade addition problem. But wearable fitness trackers (and people with PhDs) measure health numerally. Asking a small device to pull the weight of a medical-grade machine is a tall order, and all should taken with a pinch of skepticism. But a select set have proven themselves a good first line of defense against complacency.
Just like theyโre different in style, wearables vary in which metrics they measure: heart rate, calories burned and blood pressure are just a few metrics vital to determining fitness. Prospective buyers need to ask themselves two questions: will you actually wear it? And will you understand it? More data means nothing if you donโt know what it means or how itโs measured. Take a look at our breakdown of the different metrics and which wearables utilize each.
Heart rate
What is it?
The number of times your heart beats per minute.
Why is it important?
A healthy heart rate will improve sleep quality, stress levels and caloric burn.
How is it measured?
Typically measured in beats per minute (bpm), heart rate will vary between individuals according to their physicality. Most wearable devices โcheck the pulseโ through the wrist or finger. There are limitations to those methods; the most accurate way to measure heart rate is with EKGs, which monitor the electrical activity right near the heart, but the majority of wearable devices use optical sensors to track blood flow. Theyโre less accurate because the areas from which they measure pulse (the capillaries in the wrist or fingers) are farther away from the heart. Also, most wearable devices arenโt able to read heart rate while โon the runโ.
Optical Flow: Basis Carbon Steel, Samsung Gear Fit, LG G Watch R, Apple Watch, Withings Pulse O2, Fitbit Charge HR, Fitbit Surge, Suunto Ambit3, Motorola 360
EKGs: Suunto Dual Comfort Belt
Bioimpedance: Jawbone UP3 (upcoming)