umm... that last bit was blank..
I only train my real, young players. I also get them to play all the games they can, not gonna get any better sitting on the bench. Some players stats increase faster when playing in an actual game, some increase faster when in off-season training, but if you train them all every week in the off season you will see it's worth it when the new season starts and your keeper's defence has gone up by 3, or your wingers long passing has shot up.
Admittedly, does get very boring, but got to be done