How to keep an fitness app running in background

Hello everybody,

I know, that an app can request additionally time in background by calling beginBackgroundTask. But as documentation and many other posts says, it is only designed to finish a possible longer running task.

(I tried to extend background execution beyond that by calling beginBackgroundTask with a timer, but that does not seem to reliably work and seems not the way it should be used.)

As I am a developer of a fitness app, I am interested in keeping the app running in the background for a longer time (> 30min), if the user decides to turn off the device or to have another app in the front to watch a stream during the training.

There should be a way to make this work, since running apps work in the background for multiple hours without being terminated.

I even have a simple HitSet-timer-app, that works in the background, while a streaming app is in the foreground.

Can anyone help me with that or point me in the right direction?

Thank you in advance!