Tag Archives: International Journal of Behavioral Nutrition and Physical Activity

Do Fitness Trackers Really Help You Lose Weight?

By Tracey Dowdy

When the first wearable fitness trackers became popular in back 2014, “The Year of Wearable Technology,” individuals looking to improve their overall health and encourage them to exercise thought they’d discovered the Holy Grail of fitness. Since then, they’ve been used to monitor weight and to supporting healthier habits, including sleeping, eating and exercising by millions of users.  But the question remains, are they actually effective in promoting your health and fitness?

Scott Stein, Senior Editor/Reviews – Wearable Tech at CNET,  recently wrote a piece, “I Wear Fitness Trackers all the Time… and I still Gained Weight. Here’s Why.”  In his story, Stein writes, “I’ve always hoped that a smartwatch could be the Marie Kondo of my future health, eliminating the distractions, focusing on the real goals and clearing my cluttered, easily distracted mind. Instead, every day I get notifications, messages and occasional end-of-day “close the activity ring!” reminders.”

Stein asserts that while great for tracking steps and reminding you to get up and move around, an individuals’ “holistic health picture isn’t contained on the watch.” For example, his Apple Watch can remind him to close his fitness rings, but it doesn’t accurately measure calorie intake vs. calories burned.

More importantly, research has found that some of the devices produced inaccurate fitness data, which may affect users lifestyle and fitness goals or potentially lead to unnecessary activities. Fitness trackers use different sensors to collect data, and most products, regardless of brand or maker, use heart rate to calculate the number of calories burned, and motion sensors are used to measure movement. The problem is, “Heart rate alone is not an ideal indicator of calorie burn,” says Adam Sinicki of Android Authority. “The assumption is that when the heart pumps faster, you are creating a demand for oxygen and energy and thus probably engaging in an activity that is ‘costly’ from an energy perspective.” Of course physically fit individuals like my brother in law Ken, who regularly runs marathons, have lower resting heart rates than someone like me, who regularly runs her mouth. Factors like blood and air pressure, the ambient temperature of your environment, as well as your current mood can cause sudden heart rate changes.

A 2015 study by the International Journal of Behavioral Nutrition and Physical Activity found that fitness trackers frequently overestimated total sleep time, provided inaccurate data about the distance an individual traveled, and miscalculated number of calories burned.

Perhaps the biggest issue is that over time, users got very good at ignoring prompts and a third lost interest in their results after just six months. Stein summed it up best, “The fitness trackers cannot force you to be healthy, and smartwatches aren’t designed to replace doctors (in fact, the Apple Watch specifically is designed to dovetail with doctor visits). But if the Apple Watch intends to eventually be a medical tool, trainer and fitness buddy for my life — and anyone else’s — it could be a lot better at meeting me at my needs faster. After all, these apps already have years of my data: my sleep, my steps, my heart rate, my weight. Put it together already. Use machine-learning magic. Tell me the big picture. Do something that slaps me in the face the way my doctor does when she tells me I need to lose weight.”

 Tracey Dowdy is a freelance writer based just outside Washington DC. After years working for non-profits and charities, she now freelances, edits and researches on subjects ranging from family and education to history and trends in technology. Follow Tracey on Twitter.