Some ideas to make training less tedious:
1. Button to select all substitutes at once (as I do every morning, to get bonuses back up to 10%)
2. Quick-train button to train all players until they reach 87% or 81% (as I do every night)
I don't have much time in the morning on my way to work, sometimes not much phone signal, would be great to do this more quickly. Training all defence/attack/midfield (the current option) is rarely useful.