An activity tracker, also known as a fitness tracker, is a device or application for monitoring and tracking fitness-related metrics such as distance walked or run,

calorie The calorie is a unit of energy. For historical reasons, two main definitions of "calorie" are in wide use. The large calorie, food calorie, or kilogram calorie was originally defined as the amount of heat needed to raise the temperature of o ...

consumption, and in some cases heartbeat. It is a type of

wearable computer A wearable computer, also known as a body-borne computer, is a computing device worn on the body. The definition of 'wearable computer' may be narrow or broad, extending to smartphones or even ordinary wristwatches. Wearables may be for general ...

. The term is now primarily used for

smartwatch A smartwatch is a wearable computer in the form of a watch; modern smartwatches provide a local touchscreen interface for daily use, while an associated smartphone app provides management and telemetry, such as long-term biomonitoring. Whil ...

es that are synced, in many cases wirelessly, to a computer or

smartphone A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, whi ...

for long-term data tracking. There are also independent mobile and Facebook apps. Some evidence has found that the use of these type of devices results in less weight loss rather than more. Sleep tracker devices have a tendency to underdetect

wakefulness Wakefulness is a daily recurring brain state and state of consciousness in which an individual is conscious and engages in coherent cognitive and behavioral responses to the external world. Being awake is the opposite of being asleep, in which m ...

History

The term "activity trackers" now primarily refers to wearable devices that monitor and record a person's fitness activity. The concept grew out of written logs that led to spreadsheet-style computer logs in which entries were made manually, such as that provided in the US by the

President's Council on Physical Fitness and Sports The President's Council on Sports, Fitness and Nutrition (PCSFN) is an American government organization that aims to "promote, encourage and motivate Americans of all ages to become Physical activity, physically active and participate in sports". ...

as part of

The President's Challenge The President's Challenge (also called Presidential Champions) was an American program promulgated by the President's Council on Fitness, Sports and Nutrition that aimed to encourage all Americans to "make being active part of their everyday live ...

. Improvements in technology in the late 20th and early 21st century allow automating the monitoring and recording of fitness activities and integrating them into more easily worn equipment. Early examples include wristwatch-sized bicycle computers that monitored speed, duration, distance, etc., available at least by the early 1990s. Wearable heart rate monitors for athletes were available in 1981."Olympic Medical Institute Validates Polar RS800 Running Computer And Training System"
Polar, November 7, 2006, retrieved February 25, 2014
archived
February 25, 2014. Wearable fitness tracking devices, including wireless heart rate monitoring that integrated with commercial-grade fitness equipment found in gyms, were available in consumer-grade electronics by at least the early 2000s. Electronic activity trackers are fundamentally upgraded versions of

pedometer A pedometer, or step-counter, is a device, usually portable and electronic or electromechanical, that counts each step a person takes by detecting the motion of the person's hands or hips. Because the distance of each person's step varies, a ...

s; in addition to counting steps, they use

accelerometer An accelerometer is a tool that measures proper acceleration. Proper acceleration is the acceleration (the rate of change of velocity) of a body in its own instantaneous rest frame; this is different from coordinate acceleration, which is acce ...

s and

altimeter An altimeter or an altitude meter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth under water. The m ...

s to calculate mileage, graph overall physical activity, calculate calorie expenditure, and in some cases also monitor and graph heart rate and quality of sleep.Jeff Beckham
"Fitness Trackers Use Psychology to Motivate Couch Potatoes"
''

Wired ''Wired'' (stylized as ''WIRED'') is a monthly American magazine, published in print and online editions, that focuses on how emerging technologies affect culture, the economy, and politics. Owned by Condé Nast, it is headquartered in San ...

'', April 19, 2012.Jill Duffy
"The Best Activity Trackers for Fitness"
''

PC Magazine ''PC Magazine'' (shortened as ''PCMag'') is an American computer magazine published by Ziff Davis. A print edition was published from 1982 to January 2009. Publication of online editions started in late 1994 and have continued to the presen ...

'', May 22, 2013.Caroline McCarthy
"Work out, get on scale...tell your friends?"
CNET, July 21, 2010. Some also include a silent alarm.Rheana Murray
"Smartphones become fitness coaches with new wearable activity trackers"
''

New York Daily News The New York ''Daily News'', officially titled the ''Daily News'', is an American newspaper based in Jersey City, NJ. It was founded in 1919 by Joseph Medill Patterson as the ''Illustrated Daily News''. It was the first U.S. daily printed in ...

'', August 16, 2013. Some newer models approach the US definition of a Class II medical monitor, and some manufacturers hope to eventually make them capable of alerting to a medical problem, although FDA approval would be required.Dan Holden, "Worn Out: The Dark Side of Wearable Technology", ''

Metro Silicon Valley ''Metro'' is a free weekly newspaper published by the San Jose, California, based Metro Newspapers. Also known as ''Metro Silicon Valley'', as well as ''Metroactive'' online, the paper serves the greater Silicon Valley area. In addition to pri ...

'', September 24, 2014, pp. 16–18. Early versions such as the original Fitbit (2009), were worn clipped to the waist; formats have since diversified to include wristbands and armbands (smart bands) and smaller devices that can be clipped wherever preferred.

Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus '' Malus''. The tree originated in Central Asia, where its wild ancest ...

and Nike together developed the Nike+iPod, a sensor-equipped shoe that worked with an iPod Nano. In addition, logging apps exist for

s and Facebook; the Nike+ system now works without the shoe sensor, through the GPS unit in the phone. The

Apple Watch Apple Watch is a line of smartwatches produced by Apple Inc. It incorporates fitness tracking, health-oriented capabilities, and wireless telecommunication, and integrates with iOS and other Apple products and services. The Apple Watch was rel ...

and some other

smart watch A smartwatch is a wearable computer in the form of a watch; modern smartwatches provide a local touchscreen interface for daily use, while an associated smartphone app provides management and telemetry, such as long-term biomonitoring. While ea ...

es offer fitness tracker functions. In the US,

BodyMedia BodyMedia was a medical and consumer technology company headquartered in Pittsburgh, Pennsylvania. Incorporated in 1999, BodyMedia developed wearable body monitoring systems. In April 2013, BodyMedia was acquired by Jawbone for an estimated $100 ...

has developed a disposable activity tracker to be worn for a week, which is aimed at medical and insurance providers and employers seeking to measure employees' fitness, and Jawbone's UP for Groups aggregates and anonymizes data from the company's wearable activity trackers and apps for employers. Other activity trackers are intended to monitor vital signs in the elderly, epileptics, and people with sleep disorders and alert a caregiver to a problem. Earbuds and

headphones Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones let a single user listen to an a ...

are a better location for measuring some data, including core body temperature;

Valencell Valencell is a US-based biometric technology company that develops Biometrics, biometric sensor technology for Wearable computer, wearables and hearables, and provides its patent-protected technology to consumer electronics manufacturers in vario ...

has developed sensor technology for new activity trackers that take their readings at the ear rather than the wrist, arm, or waist. Numerous companies have also released devices in the form of a ring that leverage the capillaries in the finger. There are collar-mounted activity trackers for dogs. Much of the appeal of activity trackers that makes them effective tools in increasing personal fitness comes from their making it into a game, and from the social dimension of sharing via

social media Social media are interactive media technologies that facilitate the creation and sharing of information, ideas, interests, and other forms of expression through virtual communities and networks. While challenges to the definition of ''social me ...

and resulting rivalry. The device can serve as a means of identification with a community,Sherry Turkle, "Always On/Always-On-You: The Tethered Self", in: ''Handbook of Mobile And Communication Studies'', ed. James Everett Katz, Cambridge, Massachusetts: MIT, 2008, , pp. 121–137. which extends to broader participation. The standard activity-tracking smartphone or web apps present data in statistical form meant to be viewed after the activity has ended. However, research suggests that if we want a richer understanding of the data, we need intelligent computing to be included in the systems that run the apps. Some users and reviewers remain ambivalent towards the technology, making the point that in such a "mirror" displaying one's identity, misrepresentations are problematic. There is also research problematizing tracking devices in relation to how we inhabit, experience and imagine our bodies and lives. All forms of lifelogging also carry privacy implications. Social networks associated with activity trackers have led to breaches of privacy such as involuntary publication of sexual activity,Jack Loftus
"Dear Fitbit Users, Kudos On the 30 Minutes of 'Vigorous Sexual Activity' Last Night"
''

Gizmodo ''Gizmodo'' ( ) is a design, technology, science and science fiction website. It was originally launched as part of the Gawker Media network run by Nick Denton, and runs on the Kinja platform. ''Gizmodo'' also includes the subsite '' io9'', ...

'', July 3, 2011. The company has changed privacy settings to avoid this
"Updates to your profile page"
, Fitbit blog, July 4, 2011. and the potential for advertisers and health insurers to access private health data through the devices is a concern. In 2016, there were several advances made in regard to fitness tracking geared toward kids with a variety of options from organizations such as

UNICEF UNICEF (), originally called the United Nations International Children's Emergency Fund in full, now officially United Nations Children's Fund, is an agency of the United Nations responsible for providing humanitarian and developmental aid to c ...

and

Garmin Garmin Ltd. (shortened to Garmin, stylized as GARMIN, and formerly known as ProNav) is an American, Swiss-domiciled multinational technology company founded in 1989 by Gary Burrell and Min Kao in Lenexa, Kansas, United States, with headquarte ...

Wearable sensors

Wearable sensors have been widely used in medical sciences, sports and security. Wearable sensors can detect abnormal and unforeseen situations, and monitor

physiological Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemica ...

parameters and symptoms through these trackers. This technology has transformed healthcare by allowing continuous monitoring of patients without hospitalization. Medical monitoring of patients’ body temperature, heart rate, heart rate variability, brain activity, muscle motion and other critical data can be delivered through these trackers. Moreover, in

sports training Practice is the act of rehearsing a behaviour repeatedly, to help learn and eventually master a skill. The word derives from the Greek "πρακτική" (''praktike''), feminine of "πρακτικός" (''praktikos''), "fit for or concerned with ...

there is an increasing demand for wearable sensors. For example, measurement of sweat rate was possible only in laboratory based systems a few years ago, but is now possible using wearable sensors. Heart rate variability (HRV) has potential in determining the quality of an exercise regimen. Additionally, HRV is recommended among the athletic community as a warning sign for over-training. In these ways, HRV can be used to optimize performance.

Performance

Activity trackers are available both with and without display. Certain movements of the user, such as working in the household, cycling, swimming, dancing or rowing can distort the results obtained from activity trackers. In a test conducted by Stiftung Warentest, for example, no product determined the distance of a bike ride, even approximately.Fitnessarmbaender - Nur zwei von zwoelf sind gut
test.de, December 27, 2015. Retrieved on January 6, 2016 Furthermore, the determined values for the human

energy transformation Energy transformation, also known as energy conversion, is the process of changing energy from one form to another. In physics, energy is a quantity that provides the capacity to perform work or moving, (e.g. Lifting an object) or provides he ...

were erroneous. With the heart rate large deviations have been observed at wristlet trackers, and it is recommended for this purpose to use appropriate chest straps. Wristbands can be uncomfortable to wear and inadvertently be lost. For some products genotoxic substances were detected. The connection of activity trackers with

social network A social network is a social structure made up of a set of social actors (such as individuals or organizations), sets of dyadic ties, and other social interactions between actors. The social network perspective provides a set of methods fo ...

s can lead to violation of

privacy Privacy (, ) is the ability of an individual or group to seclude themselves or information about themselves, and thereby express themselves selectively. The domain of privacy partially overlaps with security, which can include the concepts of ...

, such as involuntary publication of sexual activity. The apps of some activity trackers not only transmit personal data, but also private address lists to servers on the Internet without notifying or asking the user. Even when anonymized, the mere presence of geolocation data may be a national security risk. However, the results of a study among semi-professional (half-)

marathon The marathon is a long-distance foot race with a distance of , usually run as a road race, but the distance can be covered on trail routes. The marathon can be completed by running or with a run/walk strategy. There are also wheelchair div ...

participants suggests that these users are open towards sharing tracked activity data on a voluntary basis with: friends (51.7%), family members (43.4%), or a physician (32.3%).

Medical uses

In those who are

overweight Being overweight or fat is having more body fat than is optimally healthy. Being overweight is especially common where food supplies are plentiful and lifestyles are sedentary. , excess weight reached epidemic proportions globally, with m ...

obese Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's we ...

some evidence has found that the use of these type of devices results in less weight loss rather than more after 18 months of use. However, it has been noted that the activity tracker used in this study is a now-discontinued model that is worn on the upper arm, which might be uncomfortable, and wear times of the tracker were low. One review of six studies found that there was little evidence that activity trackers improve health outcomes. Of five studies that looked at weight loss, one found benefit, one found harm, and three found no effect. Another systematic review covering 35 studies and 7454 participants, published at the British Journal of Sports Medicine, found that activity trackers increased people's physical activity by an average of 1850 steps/day. According to another study comparing 8-week interventions and four month follow-up of physical activity monitors, a guided weight loss program, and both together, activity monitoring and the weight loss program are associated with similar improvements and both combined are associated with more improvements than either alone. It is unclear whether activity changes occur in children and adolescents.

History

Wearable sensors

Performance

Medical uses

See also

References

Further reading