Google fit - Putting app to sleep & optimizing battery usage: Do they interrupt tracking KM distance?

I'm using google fit to track my walking distance for pokemon go, and I'm not sure if I need to make it "never sleep" or not allow it to be optimized for it to work well in the background. Does sleeping apps save that much battery? Should I allow google fit to never sleep or optimized for battery for it to work well? Is it worth putting it to never sleep if it doesn't take up that much battery?