Training happens on Friday.You can change training a million times during week, but only the type of training chosen on the moment of training update will count.
You can have only 1 type of training(passing, shooting, 1-on-1, etc) on any week, and it benefits only players, who have played during the week on the position(s) you choose to train. Players with more than 48 minutes on training position get full benefit.
Exeption is team training(freethrows, gameshape and stamina), in which all players on roster get max benefit.
Some more info how training works >
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