Nothing like going out for a morning run, coming home, and sitting down to a nutritious breakfast to find out that your fitness app has been hacked. That was probably the routine for more than a few people this morning as MyFitnessPal emailed users to announce it had suffered a data breach.

“The sheer scope of the attack — affecting a user base that’s bigger than the population of Japan — would make it one of the larger breaches on record,” reports Nick Turner from Bloomberg.

With the MyFitnessPal mobile app, people can track calorie intake, diet, and exercise routines. And, for those that do, about 150 million of them have had their accounts breached. Cyberattackers were able to get user names, email addresses, and passwords. In its email to users, MyFitnessPal advised, “Change your password for any other account on which you used the same or similar information used for your MyFitnessPal account.”

MyFitnessPal is not the only fitness app to run into cybersecurity concerns. In January, it was reported that Strava fitness app was sharing a little too much data in its effort to show how many people were getting fit.

Under Armour is based in Baltimore, which was also in the news this past week when the city’s 911 emergency system was under cyberattack. Under Armour bought MyFitnessPal in 2015, hoping to become the biggest tracker of fitness information, according to Bloomberg.

While the data breach occurred in late February, Under Armour only became aware of it this week. It has taken steps to notify users and is working with law enforcement to investigate the incident.

Get the full story at Bloomberg.