What does Winter mean to you?

To me, winter means:  warm blankets, fireplaces, movies, hot chocolate, soup, breads, and fresh baked cookies. And with winter comes darkness. Darkness means I have all evening to sit down, watch television and enjoy homemade comfort food. What I “don’t” have time for is a workout.  I mean, who wants to workout when it’s already dark before and after work? Motivation….Out the window!


Nevertheless, once you do find and thaw the motivation that has been frozen under 5 feet of snow, you want to make sure that when you workout, it counts! Can you trust the cardio machines that you are using?  Did you really just walk 5 miles on the treadmill in 30 minutes at 3.5 miles per hour (mph) with a calorie burn of 700? What about the brand-new technology that I received for Christmas?  It’s suppose to track my sleep, steps, and energy expenditure (calories burned) but is it accurate?  I mean, my wristband said I burned 1000 calories in 6 hours of sleeping alone in my bed.  Therefore, just like the Internet, it MUST BE TRUE!  I feel thinner already!  (Just Kidding)

Anymore, there is a huge push to move, exercise, and get physical.  Rightfully so.  It doesn’t take a Scientist to tell us that being physically active has NUMEROUS health benefits.  However, has the way society looked at physical activity changed?  Does going to the gym feel more like a job rather than a stress reliever, outlet, or a way to feel better about yourself?  With advances in technology we no longer go on a walk just for the pure enjoyment of a nice sunny day but rather, to help us hit our 10,000 steps.  If you are one of those people that prefers to have a set schedule and constant feedback, then technology is your best friend.  Nevertheless, if you plan on taking time out of your day to be physically active, wouldn’t it be nice for the technology to be accurate?


In a study that looked at the accuracy of various activity trackers the researcher compared: Nike Fuelband,  Jawbone UP, BodyMedia FIT Core, Adidas MiCoach, Fitbit Ultra, and the NL-2000i. Twenty subjects (10 male, 10 female) participated in two, 50 minute activity sessions. The first session consisted of walking on a treadmill for 20 minutes, 10 minute rest, followed by running on a treadmill for 20 minutes.  The second session included 20 minutes on an elliptical cross-trainer, 10 minute rest, and time to complete agility drills.  During these sessions, participants wore activity trackers concurrently. At the end of each session, steps and calories were recorded by all activity trackers. Steps from tracker were compared to a physical step counter.  Results concluded that all devices were fairly accurate when it came to counting steps.  Trends showed that the activity tracker underestimated steps from walking and running by 6-10% respectively.   Activity trackers greatly underestimated steps during the agility test with underestimation between 17-24 percent.

When it came to energy expenditure in calories, the activity trackers were much less accurate.  Accuracy of the tracker varied depending on the exercise modality. The Adidas MiCoach did not register movement on the elliptical and therefore cid not record any calories burned. However, all trackers significantly underestimated calories burned when participates were on the elliptical. The Adidas MiCoach was also the only tracker that was significantly different from the measured calories as they tended to overestimate calories by 34 percent while walking on the treadmill.


Overall, the purpose of the study was to assess the ability of various activity trackers to accurately measure steps taken and calories burned. For steps taken the accuracy of the activity trackers were decent and recorded no more than 10% off for treadmill walking, treadmill running, and elliptical exercise. When it came to estimating energy expenditure, the activity trackers were less accurate.   The differences between measured and predicted calories burned ranged from 13-60%, which trackers over predicting and some under predicting.

When it comes to buying activity trackers, it is important to think about what type of activity you want to track. If looking at steps taken, the Jawbone UP appears to be the best.  However, if you are more concerned about calories, there is no one products better than the other.  Rather, it goes back to knowing what type of activity you are wanting to record.  Therefore, before you go out and spend a couple hundred dollars, make sure you do your research by reading review and scientific literature regarding the new technology.

Happy Moving!



Crouter, S., Churilla, J., & Bassett, D., Jr. (2006). Estimating energy expenditure using accelerometers. European Journal of Applied Physiology, 98(6), 601-612.

Crouter, S., Schneider, P., Karabulut, M., & Bassett, D., Jr. (2003). Validity of 10 electric pedometers for measuring steps, distance, and energy cost. Medicine & Science in Sports & Exercise, 35(8), 1455–1460.

King, G., Torres, N., Potter, C., Brooks, T., & Coleman, K. (2004). Comparison of activity monitors to estimate energy cost of treadmill exercise. Medicine & Science in Sports & Exercise, 36(7), 1244–1251.

Stackpool, C.M. The accuracy of various activity trackers in estimating steps taken and energy expenditure.