Fitness trackers can be useful tools for staying active and building healthy habits, and now kids can get in on the act too. With their cool activity challenges, rewards for completing tasks, and cute, colorful designs, these devices can be fun to use and help motivate kids to move. Some have features that allow adults to set goals, dole out rewards for doing chores and homework, and monitor bedtimes, totally gamifying those not-so-fun aspects of parenting.

While the benefits are a no-brainer, it’s important to keep in mind that fitness trackers gather a whole lot of sensitive personal data about the person whose wrist they’re riding on. And with some trackers marketed to kids as young as six years old, it’s worth it to take a look at exactly how much data these devices collect from children — and consider your comfort level before you buy.

Fitness trackers collect a wide range of data

Location tracking is one big thing to consider. “I understand why parents want it, it provides peace of mind,” says Jen Caltrider, who leads Mozilla's *Privacy Not Included work to help consumers shop for safe, secure connected products. “But there are also privacy implications that are in some ways more scary than the potential for them wandering off at the zoo. Bad people can get and track locations of your kids too and (get to) know their daily routines, and follow them around. And that is pretty creepy."

In addition to personal information you or your child shares with a fitness tracker, such as name, date of birth, and gender, the devices may also collect body-related information including users’ height, weight, steps taken, active minutes, hours of sleep, and more. That goes for children and adults alike.

And while the company itself might do a decent job of keeping your data secure, third parties aren’t always so careful. In 2021, for example, health data tied to more than 61 million people using fitness trackers, including Fitbit and Apple devices, was exposed when a third-party company that allowed users to sync their health data from their fitness trackers did not properly secure thate data.

Saheli Datta Burton, a lecturer in science policy at University College London, says one of the biggest issues with data collection is that “you wouldn't really know who to, [and] at what point, with what kind of contractual obligations, a company is going to get sold to someone else down the line,” making it tough to keep tabs on your sensitive stats.

Adults can take charge — somewhat — with privacy settings and parental controls

Popular fitness tracker brands do at least seem to have some privacy considerations in place when it comes to kids. Fitbit, for one, says it does not collect location-tracking data from devices worn by children. It also features some parental controls including the ability to track your kid’s activity and approve their connections with friends.

If you decide to purchase a wearable tracker for the underage fitness buff in your life, consider a kid-specific model rather than one geared toward adults. Mozilla’s *Privacy Not Included guide reviews two fitness trackers specifically intended for children, the Fitbit Ace 3 and the Garmin Vivofit Jr 3, and neither device tracks location. (However, if you pair an app with the device, that third-party app may still track your child’s location.)

Once you’ve got a device in hand, take a few privacy setting precautions:

  • Periodically delete your kid’s data
  • Aim to store as much data as possible on the phone or device itself, rather than opting to share it with third parties
  • Turn off geolocation on the device’s accompanying app

Another tip from the experts: Consider turning off notifications, which can distract kids as they try to focus on their dance rehearsal or basketball practice.

“What we find is that when there are constant notifications popping up on a child's wrist, it can actually be a distraction from their being present in the moment, from their play, from their social interactions, and from their schooling,” says Rachel Franz, Family & Education Manager at Fairplay, a nonprofit advocacy group that aims to make the internet safer for kids.

Internet safety for kids is what’s most important

All that said, every expert we talked to (including our own) is wary about pairing fitness trackers and kids in the first place.

“There’s not a lot of empirical research that says that fitness trackers actually support children's health and wellbeing,” according to Franz. And from a developmental perspective, fitness trackers can potentially do more harm than good, she suggests.

When habits like calorie-counting and weight-tracking start young, she says, “it can sometimes institute this real competition, this real shame and anxiety around exercise, and it becomes a potential punishment, a potential source of shame,” which could lead to a child developing an eating disorder or turn them off exercise completely.

Of course, parents want to protect their kids’ wellbeing and help them build healthy habits. Mozilla’s Caltrider recommends a compromise: Hold off giving fitness trackers to kids until they’re about 12 or older; at that age they’ll be better prepared to participate in conversations with parents about how or when to share their personal data with a device.