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Don't Buy fitness trackers

by Hannah Walsh

A Don’t Buy fitness tracker will be inaccurate, difficult to use and be uncomfortable to wear. Steer clear of these frustrating activity trackers.

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Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

There's little point in buying an activity tracker that won't accurately track your health, fitness and weight loss goals, or that's so uncomfortable you won't want to wear it at all. 

Our expert lab tests separate the best fitness trackers from the models you should avoid. 

Log in or join Which? now to unlock our full list of Don’t Buy fitness and activity trackers on this page.

What makes a Don’t Buy fitness tracker?

We’ve found wearables in our tests that simply aren’t up to the task. Some are inaccurate, and will provide fitness-tracking data that’s way off the mark. In fact, the worst-scoring activity tracker from our testing overstated calories burned by more than 100%. This means you could be left thinking you’d worked off twice as many calories as you actually had. Others have straps that are so uncomfortable or difficult to use that they’d soon end up resigned to a forgotten drawer in your home, never to see daylight again.

23%One fitness watch understated heart-rate measurements by this amount during cycling tests

But we’ve also found plenty of great fitness trackers currently available to buy at great prices too. The very best models from our testing will provide you with an accurate, comprehensive and easy-to-understand snapshot of your health, activity, weight loss goals and daily exercise routine – week after week, year after year. They’ll have a range of features from long-battery life to built-in heart-rate monitors, and plenty of excellent companion apps and motivational tools to keep you inspired to be active.

How we test fitness and activity trackers

We’ve reviewed all the latest fitness and activity trackers, including devices from Fitbit, Garmin, Polar, TomTom and Samsung. We go further than anyone else in our testing, so you can be sure that you’ll find a great wearable for your needs and budget. We put the devices through a series of tough tests, and recommend only those that are good quality, accurate, easy to use and a pleasure to wear.

  • We really do go the extra mile – our test participants use every fitness watch and activity tracker while walking on a calibrated treadmill at 4.8km/h for 10 minutes, and running at 9.0-10km/h for 10 minutes. This means we can compare the trackers’ abilities to accurately log steps taken and distance travelled. For those devices with advanced sports tracking, we put them to the test on a 5km outdoor run and during swimming.
  • Our tests reflect how people use their device in everyday life. When testing activity trackers, we include routine scenarios such as carrying shopping and unloading the dishwasher, so you’ll know which devices are accurate, no matter what you’re doing. When testing fitness trackers, if they have built-in GPS, we check them for accuracy on a 1km route mapped out using a gold-standard trundle wheel. The route includes dense trees and an underpass to add the challenge of potential loss of the GPS signal. We even add a hill climb, and compare the elevation data with Ordnance Survey topographical data to get an idea of the accuracy of the distance calculator.
  • We give every fitness and activity tracker to users to try out for several weeks, so they can rate them fairly on comfort, usability, and the quality of the motivational tools or incentives.

If a fitness or activity tracker is a Don’t Buy, you can be sure it’s one to avoid. Our tests separate the watches and trackers that will really help you improve your health, from those that you’ll quickly get fed up of using.

Find out which fitness and activity trackers are Don’t Buys and which are Best Buys by joining Which? now.