Since launching our first tracker in 2007, Fitbit has transformed millions of lives by redefining what’s possible. It’s a history built by inventing the future.
Tracking your heart is incredibly valuable. And with PurePulse—the first automatic, continuous, chest strap-free heart rate technology—it’s easier than ever.
Explore the Technology See The BenefitsWe’ve taken the work out of workout tracking with SmartTrack—a technology that automatically recognizes your exercises and records them for you in the Fitbit app.
Discover How It’s Done See The BenefitsBy automatically measuring your time asleep, restless and awake, Fitbit trackers help you understand each night to make the most of each day.
Go Behind the Scenes See The BenefitsThe technology inside PurePulse was inspired by hospitals—which clipped a thimble-sized sensor onto the finger and used a technique, called photoplethysmography, to measure heart rate.
For that technique to track heart rate on the wrist, during workouts and in various environments required an extraordinary amount of research and refining.
Photoplethysmography is a long word with a short explanation: light can be used to measure blood flow.
When your heart beats, blood flows, and the volume of the blood in your wrist changes. Blood—interestingly enough—absorbs green light. The higher your blood volume is, the more green light is absorbed.
To calculate blood flow, PurePulse shines a green light onto the skin and uses light detectors called photodiodes to measure how much light is being absorbed. This measurement is used to determine how many times your heart beats per minute.
With PurePulse, tracking your heart rate trends is just the beginning.
Measure heart rate when you’re most rested to assess your heart health.
Use real-time heart rate zones to understand your effort during workouts.
See how fit you are and gauge oxygen consumption without a strenuous V02 Max test.
Relax anywhere with personalized breathing sessions based on your heart rate.
With validation from a number of external studies, PurePulse technology has surpassed industry expectations and is fueling research across the globe.
19+ patents awarded to Fitbit’s heart rate innovation
sleep insights
sleep stages
Using the power of PurePulse® heart rate, sensitive motion detectors and powerful algorithms, Fitbit’s R&D team unlocked the key to understanding your sleep quality: sleep stages.
Now, your Fitbit tracker can record your time spent in light, deep & REM sleep, as well as your time awake, then distills that information in easy-to-reach graphs in the Fitbit app.
3+ billion
sleep logs recorded by Fitbit users across the globe
80%
of Fitbit users with automatic sleep tracking log their sleep
Director of Sleep & Health Research
The University of Arizona
Stanford University
Johns Hopkins University
