Fitness tracker

A fitness tracker or activity tracker is an electronic device or app that measures and collects data about an individual's movements and physical responses in order to monitor and improve the individual's health, fitness, or psychological wellness over time.

Fitness trackers are a more sophisticated version of the pedometer; in addition to counting steps, they contain additional sensors such as accelerometers and altimeters to collect or estimate information, including the speed and distance travelled, heart rate, calorie expenditure, or the duration and quality of sleep.

Improvements in computing technology since the 1980s, recently driven by the rapid advancement of smartphones, paved the way for the spread of wearable tracker devices with integrated sensors. A large amount of sensitive sensor and user-input data is synced with mobile apps such as fitness, mood, sleep, water intake, medicine usage, sexual activity, menstruation, and potential illnesses. The large volume of data collected has led to privacy concerns around how consumer information is stored and analyzed by the companies involved.

Wearable heart rate monitors for athletes were available in 1981. Improvements in technology in the late 20th and early 21st century made it possible to automate the recording of fitness activities, as well as to integrate monitors into more easily worn equipment. The RS-Computer shoe was released in 1986. Early examples include wristwatch-sized bicycle computers that monitored speed, duration, distance, etc., available at least by the early 1990s. By at least the early 2000s, wearable fitness tracking devices were available as consumer-grade electronics, including wireless heart rate monitors that could be connected to commercial-grade exercise machines in gyms. Athletes are usually tracked with the levels of internal and external loads, where external loads will consist of the performance outcomes usually witnessed by coaches, and internal loads consist of factors such as heart rate, blood pressure, and blood lactate levels. When taking into account the well-being of the subject, subjective scales are involved which measure fatigue, sleep quality, emotions, and soreness.^{[non sequitur]}

Fitness trackers later diversified to include wristbands and armbands (so-called smart bands) and smaller devices that could be clipped wherever preferred. In 2006 Apple and Nike released the Nike+iPod, a sensor-equipped shoe that worked with an iPod Nano.

By 2010, logging apps had been introduced, many of which enabled the direct sharing of data to Facebook ot Twitter. Fitness trackers became appealing to consumers because of the combination of gamification, the social dimension of sharing via social media, and increased motivation due to the resulting rivalry and competition between friends.

In 2016, there were several advances made regarding fitness tracking geared toward kids with a variety of options from organizations such as UNICEF and Garmin.

Most consumer fitness trackers are worn on a wristband similar to a wristwatch. This type of tracker usually includes a digital display for data. Wrist-based trackers may be prone to error during exercise involving rapid arm motion.