From the guide:
"Should I do team training?
Generally speaking, do not train game shape (unless you have a good reason to do so). It is recommended to train free throws and stamina in weeks with only 2 games because stamina and free throw training will give the whole team full training in a week where you can’t give all of your normal trainees training. Note that when training free throws and stamina, trainer level is not taken in to consideration. This means that stamina and free throws will train with a level 1 trainer the same way it would with a level 7 trainer."