Ships with the Training mission use supplies from the planet they orbit to gain experience.
Experience_added = EPTrainingScale * Points / (Sqrt(Hull_Crew) + 1) ...where Points = Supplies if Supplies ≤ 25 Points = 25 + Sqrt(8*(Supplies-25)) otherwise
(4.0i) Academy ships receive four times as much experience from training.
See Experience Training for a more detailed explanation of training.