Somewhere along the way, someone told you to force quit apps on your iPhone and iPad to improve performance and save battery life.

Stop doing that.

We’ve all done this at one point or another because we learned it’s a good idea to close applications that are hogging system resources on slow-running computers. When too many apps are running at once, it can make a perfectly good system feel like it’s trudging through thick mud.

Apple‘s iOS, which powers iPhones and iPads, doesn’t work like a traditional computer operating system. Closing apps doesn’t help your performance or improve battery life.

In fact, according to the developer and Apple watcher John Gruber, it’s doing the opposite.

Gruber recently explained that apps running on an iPhone or iPad are frozen in state when they’re not being used, which means they aren’t taking up system resources as much as, say, an app on a computer might be if it were just minimized to your system tray. The apps stay frozen and don’t suck battery life.

The act of closing and reopening takes up more resources, he said:

[IOS] is so good at this that unfreezing a frozen app takes up way less CPU (and energy) than relaunching an app that had been force quit. Not only does force quitting your apps not help, it actually hurts. Your battery life will be worse and it will take much longer to switch apps if you force quit apps in the background.

Gruber points to an email to an Apple customer from Apple senior vice president of software engineering Craig Federighi, who said he doesn’t close apps and that doing so doesn’t save battery life.

There you go, myth busted.