Fitness trackers look simple enough. Most are designed to measure heart rate, steps taken and various kinds of movements, as well as compile key health data via mobile apps. This data, in turn, can help people achieve their exercise goals and make other lifestyle changes to improve their health.
Yet these handy devices can also perform unexpected feats, such as automatically turning on your lights, matchmaking and even recording potentially life-saving data. Here's a look at some of those surprising features.
David Trinidad, also known as Reddit user YoungPTone, at first thought his wife's fitness tracker was broken. He posted a question to Reddit in February 2016, asking why the device showed she had a consistently higher heartbeat than a few days earlier. Amid all of the technical support responses, one user suggested it might be stress — or pregnancy. A day later, the thread got confirmation from Trinidad: "I'm going to be a dad!" Indeed, an increased heart rate is a possible sign of pregnancy, according to Beth Israel Deaconess Medical Center experts.
In 2015, Jawbone got into the mobile payments game with its Up4 fitness tracker. The device allows eligible American Express members to connect their cards to the fitness tracker. From there, they can make a secure payment by tapping the tracker on a store's mobile-payment terminal. Jawbone's tracker relies on the same NFC technology as Apple Pay. Fitbit also purchased mobile-payments technology, so that it can integrate it into its future wearables.
When a 42-year-old man who had a seizure, followed by a fast, irregular heartbeat, arrived at an emergency room in Camden, New Jersey, doctors weren't sure whether using a defibrillator would help or hurt him. Then, they spotted his Fitbit Charge HR. The fitness tracker data showed he was at low risk for a dangerous clot — so they used a defibrillator, and his heartbeat returned to normal. This wasn't the first time a fitness tracker was used when diagnosing a medical condition: a high school student was diagnosed with rhabdomyolysis after his Apple Watch showed that his heart rate jumped from 70 to 145 beats per minute, according to LiveScience.
Garmin's vivoactive HR is a GPS-enabled tracker with some smartwatch-like features, such as the ability to load apps to the device. Garmin's Find My Car app can save your car's location on a vivoactive device, keep track of a running meter and guide you back to the parking spot with a helpful directional arrow.
Garmin product architect Joseph Rakolta released an app called SkyWatch that can be downloaded to a number of the company's GPS watches, such as the fenix 3. By tapping into the devices' GPS and compass sensors, SkyWatch reveals the exact location of the moon, planets and constellations (such as Orion and Cassiopeia) in the night sky.
Monitoring is a vital part of cancer care. In 2014, researchers from the University of Texas MD Anderson Cancer Center studied more than 130 patients who wore commercially available fitness trackers for two weeks. Most of the cancer patients found the trackers easy to use, and the devices helped the participants follow prescribed treatments. For example, patients with colon cancer could track physical activity, which has an impact on their long-term survival, according to LiveScience.
When self-motivation isn't enough, many fitness-tracker apps have a built-in community function, with which you can see how many steps your friends are taking, and send messages encouraging them to take more — or gloat that you're kicking their butts. Stridekick's Matchup app lets fitness-tracker users compete against friends, family members or complete strangers. Matchup works with devices from a range of tracker makers — including Fitbit, Jawbone, Withings, Garmin, and Misfit — and invites users to join a fitness competition or create a new one. The "Head to Head" challenge mode matches users with a different opponent every day to see who takes the most steps.