There are many devices currently on the market that facilitate the tracking and analysis of physical activity. Most of these physical activity tracking devices are digital and designed to sync with cell phones, tablets, web-based fitness applications and social media applications. These devices are sleek and informative – but are they really worth buying?
Pedometers are essentially “step counters” that, if worn properly, quantify physical activity in terms of the number of steps taken. Often, you can upload information from digital pedometers to applications designed to track activity over time. Pedometers have been around for a long time and are frequently used in research studies related to physical activity. Most are reasonably accurate and provide a nice snapshot of daily activity levels. Accelerometers are similar to pedometers but also assess additional movement characteristics such as acceleration of movement, which can be related to exercise intensity.
Devices also estimate caloric expenditure. It is important to keep in mind that these are merely estimates based on the data the devices are reading – they are indirect measures of caloric expenditure. Calories are actually units of energy. To directly measure caloric expenditure, one would assess changes in temperature within a closed chamber to calculate an individual’s energy metabolism. Clearly, wearable activity trackers are not measuring caloric expenditure in this manner (directly). Rather, the devices use algorithms to estimate caloric expenditure based on factors such as height, body weight, age, sex, activity mode, duration, and in some cases, intensity. While less precise than direct calorimetry, this can provide a reasonably accurate estimate of caloric expenditure. It is important to note, however, that, as with indirect estimates of any sort, such as body mass index (BMI), these are based on averages over large populations.
|10,000 Steps Per Day|
|10,000 steps has become the consensus threshold for daily physical activity. (Probably because we have ten fingers and we love numbers with lots of zeroes.) This activity level has been associated with an array of health benefits, including weight, blood pressure and glucose level reduction. It is important to keep in mind that exercise benefits our health in a dose-response fashion – that is, the more we do, the greater the benefits (up to a point – overtraining isn’t healthy). So, increasing your activity likely will result in health benefits even if you aren’t quite making it to 10,000 steps; likewise, adding more steps may lead to additional benefits even if you are already getting 10,000 daily steps.|
Sleep Quality Trackers
The current crop of digital activity trackers track not only physical activity and caloric expenditure – many track sleep “quality.” The idea is that the accelerometer tracks movement while the wearer is sleeping, and it uses the movement data to estimate the quality of one’s sleep. While interesting, there is some skepticism regarding the accuracy of sleep “quality” estimates provided by these devices.
So it is clear these trackers may be thought of as data collection devices, able to provide us with information about our own physical activity habits and goals. This is valuable because many of us do not think much about how many steps we take or how many calories we burn. As such, the ability to quantify and track the data lets us know approximately how active we are, and whether we are on track to meet fitness or weight-loss goals.
There is a strong case to be made that this feedback mechanism may help to motivate us in and of itself. The Hawthorne effect is a phenomenon which dictates that individuals modify behavior as a reaction to being “observed,” generally in the context of participation in a research study. Tracking daily physical activity creates this observation scenario, and may serve as motivation to be active. The motivation may stem from the desire to accomplish daily or weekly goals, or from peer accountability via the social media applications, which can make the tracking “fun” through the ability to create groups and competitions and adding a social element to activity tracking. Whatever the source of motivation, an increase in physical activity is a positive result.
Contributed by Andrew Lorino. Andrew Lorino is the Senior Director of Membership Experience at the YMCA of Greater Houston. He holds a master’s degree in Exercise Science, with an emphasis in exercise physiology and statistics, and has served as an adjunct professor and graduate research assistant at the university and community college levels.