How much time should a pilot study during airline training?

Airline pilot hiring is improving and many pilots are getting their chance to go to the airlines. For many, this will be their first time to any formal airline pilot training. Airline pilot training is not easy to get through and requires a lot of time studying. For the first three weeks or more, a pilot will go through basic indoctrination and aircraft systems training. This usually consists of eight hours a day of training, which does not leave very many hours at the end of the day. Usually at the end of these days the pilot is very fatigued.