How to sync data between Polar V800 and the Polar Flow app?
After you've paired your V800 with your Flow app, you can sync your data just by pressing and holding the BACK button from the clock view on your training device. Or you can go to Settings > General settings > Pair and sync > Sync data if you want to press the buttons of your training device even more.
The sync works both ways, so the training data from your V800 will show in the app and if you've made any setting changes in the app, they will show in the settings of your training device too.
The Flow app also syncs the data to the web service so you can access your up-to-date training data wherever you want.