In previous NFL Madden Mobile games you could uprade every player in the game a certain number of OVR levels which would also increase their ratings. Now in Madden NFL Overdrive you can only increase the ratings of your Captains and they have their own currency for doing so called Captain Badges. For gold or better players, using Training Points will increase their power level and not their attributes.
Training your players will now add to your Team Power Rating which will be compared to your opponents power in a game of Overhdrive H2H and whomever has the most power will recieve an OVR boost to their entire team which will last for the duration of the match.