Fitness trackers employ many different types of technology in order to provide the available services and applications and measure different personal parameters.
While this technology serves an overall beneficial purpose, it has negative consequences as well and may not always be the most accurate method of measuring specific faculties. Bluetooth technology is used in many fitness trackers for the main purpose of syncing with other devices. Syncing allows for the worn device to connect with applications on shared devices such as mobile phones or computers, and to record and display statistics relating to activity and other assets measured by the fitness tracker.
Bluetooth is a technology designed to transmit signals over short distances, up to a maximum of 100 feet apart. It provides connectivity between devices such as mobile phones, computers, speakers, and headsets without use of cables, for applications such as messaging and music. Bluetooth receivers process information found on frequency hopping bands to prevent hindrance from stable bands and are centered around 2.4 gigahertz. According to Scientific American, interference is minimized by forming a piconet, a radio channel shared by a group of devices that are synchronized to a common clock and frequency hopping pattern, with the master device providing synchronization references to the slave devices (2018). When devices come within range of one another, the link managers for each device discover each other and make a connection, allowing engagement of message exchange, including segmentation and reassembly of packets if required (Techspirited, 2018). Wireless internet, more commonly referred to as Wi-Fi, is an alternate means of connecting fitness trackers to additional devices. Generally used in phones and personal computers, this technology may also be used to connect fitness trackers directly to a router without the use of wires or cables for internet access.
Wi-Fi on fitness trackers enables the uploading of data to servers to be stored and displayed on a mobile phone, tablet, or computer, or provides connection to an access point to download applications or utilize the internet.An accelerometer uses three separate planes to measure location which, when used in junction with fitness trackers, determines the distance moved throughout the day. Accelerometer technology tracks change in speed over time in the X, Y, and Z axis, or acceleration in movement occurring front to back, side to side, or up and down. Algorithms determine what is and what is not a step by determining “whether a motion’s size is large enough by setting a threshold. If the motion and its subsequent acceleration measurement meet the threshold, the motion will be counted as a step” (Fitbit, 2018). Algorithms may be personalized by drawing from the information such as height, weight, and placement of the tracker on the body, provided to the fitness tracker’s corresponding application on the mobile phone or computer by the user (Lashkari, 2017). This data is compiled to determine the number of calories burned up to the current point in the day.
The accuracy of the gathered data may be affected by different factors, such as tasks performed involving exaggerated arm movements. This may skew the data and cause reflection of more steps, while walking or running with minimal arms movement may have opposite results. Travelling on uneven surfaces may also cause for inaccurate data to be recorded, as wrist movements will be abnormal and vary for each step taken.
In his article, Michael Sawh explains pulse oximetry as a technology used to measure heart rate by detecting changes in the blood oxygen level of a person in the parts of the body furthest away from the heart by using red and infrared light (2018). The light is shone through a person’s finger, while sensors read and interpret the amount of light passing through the finger versus the amount of light being reflected by blood (Nonin, 2016). Pulse oximeters are used at medical facilities in the form of finger clasps and may assist in tracking sleep apnea by noting a halting of breath during rest periods, and an individual’s ability for physical activity. The Global Positioning System, or GPS, is a method of determining location using multiple satellites and GPS receivers placed at points on the ground to provide relative coordinate navigation worldwide. This technology is most accurate in places of high population density, due to closer positioning of receivers, and decreases in accuracy in direct relation to decreasing population. GPS is a space-based radio-navigation system used to determine a three-dimensional location in comparison to latitude, longitude, and altitude. Three factors are used in determining location – placement of the corresponding satellites, surrounding ground receivers, and device requesting the GPS location (Mai, 2014).Sleep measurements are taken by an actigraph, a piece of technology designed to measure sleep cycles and patterns by measuring periods of stillness and movement during the resting period.
Usually worn on the wrist, an actigraph commonly employs accelerometers to measure movement and record motion. For this reason, actigraphs may record still periods as periods of sleep, resulting in an overcalculation of total sleep. To counter this, it is suggested to keep a record in the form of a sleep log, specifically times of lights out and wake times.
To individuals who do not keep a sleep log, this may prove to be a disadvantage and lead to overcalculation of the amount of rest received as typically actigraphs prove most accurate for those with normal sleep cycles and not suffering from sleep apnea or other sleep irregularities. Another factor one should consider when using a fitness tracker is the ability to share data. While this may, along with setting reminders to move every certain length of time, be a strong motivational strategy, it can be dangerous if not monitored carefully. The social media app Strava tracks workout statistics, including location and routes travelled, and builds heat maps accessible to the public off of information recorded by the users. As a result of the exercise paths, locations of secret military bases are able to be analyzed putting them at a higher risk to be compromised.
While one should be aware of the information he or she shares with the public and who has access to view the shared information, “sharing with Strava is an option that must be opted out of, not opted in to and therefore easy to overlook” (Romano, 2018). Despite the disadvantages of sharing figures from a workout, it may also be a positive means of motivation. Sharing allows one to display progress and challenge others, encouraging improvement. If an individual simply needs the motivation to move, reminders are able to be set on many fitness trackers if the user has not met the step goal each hour. Many platforms of technology are found on and work with fitness trackers, from medical applications to self-motivating functions. While precaution must be taken in using fitness trackers, the fact remains that the technology encourages activity and gives one the ability to measure improvements and track data provided by the device.