Mr. Albert Mendoza, a doctoral candidate in the University of Massachusetts Amherst department of kinesiology, was recently awarded a one-year, $27,857 grant through the National Institutes of Health’s (NIH) Ruth L. Kirschstein National Research Service Award Individual Predoctoral Fellowship to Promote Diversity in Health-Related Research program. Mr. Mendoza will use the funds for a study titled “Validation of activity trackers in estimating energy expenditure, activity minutes and steps in free-living settings,” which will examine the accuracy and precision of consumer fitness trackers. The study will be the first using these devices as well as direct observation to monitor individuals in their day-to-day lives rather than a laboratory setting.
“Having participants doing activities in free-living settings will allow us to understand how well these devices detect a person’s activity level,” notes Mr. Mendoza.
As participants go about their activities, they will be wearing a mix of ten consumer and research grade activity monitors on their bodies. The researchers will compare the results from the activity monitors with calculations by the research team themselves.
“We’re actually using direct observation. We’ll follow the subjects with a GoPro camera while they go about their daily activities in two-hour blocks on several separate days,” he explains.
Back in the lab at UMass Amherst the researchers will calculate activity level using The Observer XT, a computer program that allows them to view the video, note a person’s activities, and assign these activities numeric values that will be compared onscreen with data from the activity monitors.
“We’ll also examine how well consumer activity trackers detect changes in behavior,” Mr. Mendoza adds. For example, they will examine whether the devices detect a change in energy expended when a subject spends one session doing very active things such as cleaning the house and then spends much of the next session sitting in a car on a long drive. While he cannot predict the results, Mr. Mendoza has informally tested consumer fitness trackers on runs with a group of local runners called the Shutesbury Coffeecake Club.
“The distance measurements are never quite the same, even though we are all taking the same route together,” he says. Mr. Mendoza is conducting the study along with his PhD advisor and mentor, kinesiology professor and chair Dr. Patty Freedson, as well as professor of math and statistics Dr. John Staudenmayer.
“I feel thankful and humbled for this opportunity as well as the support of the University,” he says. Mr. Mendoza notes that Drs. Freedson, Staudenmayer, and School of Public Health and Health Sciences grants manager, Ms. Linda Downs-Bembury have all been key to his successful grant application. In addition to the NIH grant, Mr. Mendoza has also received support for his doctoral studies from the UMass Amherst Institute for Maximizing Student Development (IMSD), which gives grants to encourage more minority students to pursue doctorates in the sciences, technology, engineering and mathematics and become professors. With the increasing popularity of activity trackers, he thinks the study will be a first step in the research community assessing accuracy of these devices.
“It’s up to us to build evidence of the accuracy, precision, and sensitivity to change of these devices so the public can make informed decisions about using them,” he says. “I really hope it’s meaningful to the public. Ultimately what’s important is that an individual finds something, whether it’s an activity tracker or some other fitness gadget, that helps them achieve their own health goals,” Mr. Mendoza adds.