I think there is a little bit of a mix up there. To clarify.
Military Academies increase both the number of officers(5 per year per academy) and crew(1000 per year per academy at racial training level 1) available. You can also increase the number of crew by assigning an officer with high training bonus to a ship, leaving it for a while to allow the crew rating to increase and then scrapping the ship, adding a potentially larger number of crew than was used when initially building the ship dependant on the ships crew rating and racial training levels. This does not require any special actions by the ship, just time, and it does not consume fuel. However it is normally far better to spend the equivalent amount of resources building Military Academies instead.
Task force training rating, which does require sending a ship on special training exercises which consume fuel as they move around, is a separate value that effects how fast the crew will respond to orders. This has no effect on the number of crew that will be returned to the pool if the ship is scrapped.