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Can Wearable Fitness Trackers Help Meet Physical Activity Goals?

Similar to in years past, weight loss behaviors such as diet and exercise are among the most popular New Year’s resolutions in 2018. But in order to increase their exercise behaviors successfully, people must be able to accurately measure their exercise. Unfortunately, most of us are notoriously bad at doing this ourselves. Research shows that people often overestimate their exercise intensity, frequency, duration, and calories burned from activity.

Therefore, there is a need for easy, affordable ways to assess physical activity accurately—both for individuals hoping to improve their health and for scientists studying physical activity. Commercially available activity monitors such as the Fitbit, Apple Watch, or various smartphone applications have the potential to provide objective physical activity measurements. Scientists at Fors Marsh Group have experience not only using these devices in our research, but also evaluating them to determine which ones are the most appropriate for each study.

The utility of any activity monitor for research depends greatly on the goals of the study. Researchers collecting observational data may wish to measure physical activity without influencing it. We at Fors Marsh Group would help these researchers identify devices that are convenient and accurate but provide as little feedback to or interaction with the participant as possible. I recently published an article in the journal Psychology of Sport and Exercise examining the utility of Fitbits and electronic daily diaries for measuring physical activity without changing it. Participants were randomly assigned to one of four groups: (1) Fitbit only, (2) electronic diary only, (3) Fitbit and electronic diary, or (4) no device. Participants who used a Fitbit were not given access to the accompanying smartphone application or any of the feedback that it provided, but they could see their daily steps on the device’s screen. All participants reported their activity at baseline and one week later.

Results were encouraging but a bit surprising. Using the Fitbit for one week did not increase participants’ actual physical activity compared to any other group, as we had predicted. However, we also measured participants’ perceived physical activity. After a week, participants who used only the Fitbit perceived their physical activity as higher than they had thought it was at baseline. This change was not seen in any other group. This suggests that while using a wearable device like a Fitbit does not necessarily change behavior, it may change perceptions of behavior.

In contrast to simply observing physical activity, some researchers use activity monitors to improve participant physical activity. In these situations, we would help them identify devices that provide theoretically based strategies known to improve behavior, such as goal setting, feedback, social support, and reminders. For example, a researcher aiming to encourage participants to reach a standard goal (e.g., 10,000 steps per day) or a goal customized to the needs of the participant (e.g., 5,000 steps per day for a more sedentary individual and 20,000 steps per day for a very active individual) may prefer a pedometer or other wearable device that has an accompanying smartphone application to measure steps accurately. The application would also provide clear feedback to participants regarding their current physical activity and strategies to meet their goals.

Many devices, such as a Fitbit, have accelerometer technology, which measures intensity. This technology allows researchers to set more specific goals such as meeting the CDC’s recommendation of 300 minutes of moderate or 150 minutes of vigorous physical activity per week. Commercially available devices like the Fitbit or Apple Watch are good examples of devices with accelerometer technology.

Given how difficult it is to improve physical activity, we recommend that researchers consider newer devices and applications that also offer reminders and social support. A Fitbit will notify participants when they have been inactive for a specified amount of time. Researchers have found that participants generally have neutral or positive feedback toward wearable devices that use idle/sedentary alerts. In exit interviews, some of the barriers that participants reported to using idle alerts include social norms—such as what to do if an idle alert goes off in a public space like a movie theater and habituating to the vibration of the alert. Various smartphone applications also provide social support by sending participants encouraging messages when they have met certain goals or connecting participants with other users so they can encourage and support each other.

In addition to considering the goals of each study, Fors Marsh Group can help researchers account for the lifestyle and exercise habits of the participants. Smartphone applications may be ideal for someone who primarily exercises by walking around or running on a treadmill. However, people who play on an organized sports team, take group fitness classes, or swim may not be able to keep their smartphones with them while exercising. Similarly, devices that only measure steps may not be suitable for someone who primarily lifts weights, take spin/cycling class, or does Pilates or yoga, since these do not involve many steps. Devices that are waterproof, durable, clip on to clothes or around one’s wrist, and measure heart rate may be viable solutions for some of these issues.

Today, there are various publicly available devices that can be used to measure physical activity objectively and even help improve it. Scientists at Fors Marsh Group are excited to leverage our expertise with wearable devices to help researchers tailor their methods better to the target population and goals of each study.

About the author

Miriam Eisenberg Colman

Miriam Eisenberg Colman

Dr. Miriam Eisenberg Colman joined Fors Marsh Group in October 2017 as a senior scientist in the Communication Research division. Currently, she works primarily on the Food and Drug Administration’s (FDA) Childhood Obesity Focus Groups study and the FDA’s Healthy Claims experimental study.

Before joining FMG, Dr. Eisenberg Colman received her Ph.D. in Applied Social Psychology from The George Washington University and worked for three years as a postdoctoral fellow at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) at the National Institutes of Health (NIH). In her more than 10 years of research experience, Dr. Eisenberg Colman developed expertise in experimental, survey, and qualitative methods as well as complex statistical analyses using large-scale, nationally representative data sets. Dr. Eisenberg Colman has published numerous peer-reviewed journal articles, spanning topics such as diet quality, physical activity, obesity, sleep, child and maternal health, diabetes management, unhealthy weight control behaviors, substance use, and mobile and digital health.

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