LONDON (AP) — GPS device-maker Garmin’s online fitness tracking service has gone down, leaving runners and cyclists struggling to upload data from their latest workouts.

Garmin Connect, an app and website that works with the company's popular line of fitness watches, remained out of service on Friday. The U.S. company had apologized for the disruption a day earlier, when it indicated the problem was more widespread and also affected its communications systems.

FlyGarmin, the company's navigational support service for pilots, was also hit by the outage, which down took the service's website and mobile app.

“We are currently experiencing an outage that affects Garmin.com and Garmin Connect,” the company said on its Twitter accounts and website. “This outage also affects our call centers, and we are currently unable to receive any calls, emails or online chats. We are working to resolve this issue as quickly as possible and apologize for this inconvenience."

Fitness enthusiasts took to social media to vent their frustrations about not being able to use the service. Runners said that while the outage doesn't stop them from training, not being able to use Garmin Connect means they can't track their workout data or share their routes on Strava, a social network for runners and cyclists.

Atlanta tech executive Caroline Dunn, who runs five days a week and finished the New York Marathon in 2018, said the outage means she and her running friends can’t send each other kudos - Strava’s version of Facebook’s likes - to encourage each other.

“We’re not doing this for our health, we’re doing this so that we can brag to our friends," Dunn said lightheartedly. “Now that we’re all social distancing, I don’t run in a group with my friends and they don’t watch me run. I have to brag online to my friends about all of my runs.”

The outage is also preventing athletes from proving that they’ve completed virtual runs that are replacing the many races cancelled because of the pandemic, Dunn said. Runners who use the Garmin system can’t be ranked because they can’t submit GPS data to organizers.

Tech-savvy users shared a workaround: plug the watch into a computer with a USB cable and manually transfer the files.

Some users also complained that Garmin's lack of communication was a bigger problem. Massimo Gaetani, an entrepreneur in Cambridge, England, said he was disappointed the company wasn't updating users after its initial tweets on Thursday.

Dunn and Gaetani said the lack of information fueled speculation the outage was caused by more than routine maintenance, with a cyberattack the possible culprit. Some tech websites have reported that the company has been hit by a ransomware attack but the company hasn't confirmed it.

"An outage usually is measured in minutes," said Gaetani, who is 55 and started using a Garmin device last year to track his heart after being diagnosed with an irregular heartbeat. “A 24-hour outage is not a normal computer reset procedure. Obviously something is very wrong.”

Connecticut runner Megan Flood saw the prolonged outage as both a curse and a blessing.

“It’s frustrating in part because my Garmin is connected to my Strava (fitness app), and I like the community aspect on Strava,” Flood, 27, said Friday. “But sometimes not being so connected to my device is nice. I’ve run some of my best races when I forgot my watch or covered my watch face, so I find there are pros and cons to be so connected to a watch.”

___

William J. Kole in Warwick, R.I. contributed to this report.

___

Follow Kelvin Chan at twitter.com/chanman