the sad thing is that next season, if you are as unlucky as me and end up on a server with teams from league 3-4-5 ....then this player - despite training like a madman - will be pretty average for a long while (because the players on the new season's transfer market will be sooo much better than the previous season).
If that happens, you will have spend all these tokens and rest packs on a player that is avg because of you ending up on the wrong server. Happened to me last season. That's why i stopped doing power training