Many of us have invested in the wristbands or other wearable devices that tell us how many steps we’ve taken, calories we’ve burned and other information. But an interesting new study that compared activity monitors found that while some are accurate when measuring step counts, others are way off. And few are more accurate than the convenient and inexpensive apps you can find on your cellphone.
What’s more, the researchers say, while many of us hope that these activity trackers may motivate us to become more active and healthier, none of them has proved able to persuade reluctant exercisers to start and stick with a workout routine.
The promise of these devices obviously relies heavily on their accuracy and ease of use. If the trackers tell us that we have moved more or less than we actually do, our responses may not be appropriate or ideal. If, for instance, the monitor says that we have burned more calories than we actually have that day, we may overeat and gain weight. If, alternatively, the monitor says that we have taken fewer steps in a day than we actually have, we may become discouraged, blame the device, throw it in a drawer and stop walking for exercise altogether.
Similarly, if a fitness monitor is difficult to programme, requires frequent charging, feels uncomfortable or is pricey, many people who might benefit from more exercise will avoid buying or wearing the thing.
A majority of Americans own a smartphone, however, and recently, a number of apps have become available that promise to measure someone’s steps, calories and so on, much the way a wearable fitness tracker does, but at a lower cost and, presumably, with greater convenience.
The accuracy of these phone apps, however, has not been established, especially in comparison to the accuracy of the dedicated fitness trackers.
So for the new study, which was published this week in JAMA, researchers at the Perelman School of Medicine and the Center for Health Incentives and Behavioral Economics at the University of Pennsylvania in Philadelphia purchased three of the most popular wearable fitness trackers — the Fitbit Flex, the Nike Fuelband and the Jawbone UP24 — as well as a clunkier pedometer and several types of accelerometers, which are often used by scientists to track people’s physical activity.
They also looked at four fitness-tracking applications for iPhones and Android-based phones, including an iPhone application from Fitbit and the Moves application for both types of phones.
Ultimately they gathered 10 separate devices or apps that claim to track steps and otherwise monitor health and fitness.
Next they rounded up 14 game adult volunteers and loaded them up with the devices.
Each volunteer was fitted with a pedometer, two accelerometers, several wristband monitors and, in each pocket, a cellphone, one of which ran three iPhone-based fitness-tracking apps and the other of which featured an Android phone running one tracking app.
The volunteers then began walking on treadmills set to a gentle 3 miles-per-hour pace. A researcher stood nearby and manually counted every step each volunteer took until that volunteer had finished first 500 and then, separately, another 1,500 steps.
Each volunteer completed two sessions of this step counting while wearing all of the devices.
Then the researchers compared the step counts that the devices had recorded against those objectively measured by the researcher (who was unlikely to have miscounted by more than a step or two).
The totals diverged considerably. The pedometer and the accelerometers were generally quite accurate, but one of the wristbands, the Fuelband, underreported the number of steps the volunteers had taken by more than 20 percent.
Others of the monitors were more accurate but, by and large, no more so than the smartphone apps, which cost much less and would likely be more convenient for
The upshot, said Dr Mitesh S Patel, an assistant professor of medicine at the University of Pennsylvania who oversaw the study, is that smartphones could offer “an easy, less expensive, but still accurate” means for people to track their activity.
What’s your pick?
- Can travel where you are and is relatively inexpensive — and sometimes even free
- Can be used anywhere as programmes don’t require weights or other equipment
- Can’t opt to change fitness level after you start the programme to make your workouts harder or easier
- Can’t adjust workouts for injury
- Does not motivate one to exercise
- Can create a safe and effective workout
- Can create more difficult workouts giving you a sense of achievement at the end of it
- Can motivate more, push you harder
- Can be expensive and sometimes inconvenient
Kiqplan is a workout plan sold in stores as a gift card that unlocks a 12-week workout (choose from Slim and Trim, Beer Belly Blaster and others). The app includes nutrition coaching, integration with activity trackers and rewards for hitting certain milestones.
Hot5 has a collection of high-intensity five-minute workouts that you combine into longer sessions, with nice videos that feature a variety of trainers.
FitStar is a free personal trainer app. For a yearly fee, you get access to more workouts. It can build workouts customised to your fitness level and goals. (By Molly Wood)
– By Gretchen Reynolds