is called "power train" ... spending tokens to buy only players 18~19 y.o fast trainers and green/red boosts to refill the condition of player after train , since you can get into few days a lot of skill points with the right price (time + tokens) then you get the perfect team !

i just powertrain a player to 7* but i cannot afford to grow him more so , power train is for the one who spend a lot of money !