Keep app running after screen turns off

[drjim]

I'm a runner and cyclist, and I just installed and tested Endomondo, which appears to be the most popular app for measuring distance, speed, etc.

The problem I have is that when my screen goes off, Endomondo doesn't continue to record my route. It is still running, but when I open it again, it has stopped recording my run or bike data.

Suggestions?