What are the 3 stages of a workout, and the 3 principles of training for fitness?

This is for my health exam coming up. It asks what the 3 stages are for a workout, but somehow i turned out with 4.. which were aerobic finess, muscular fitness, flexibility, and endurance... Help?!What are the 3 stages of a workout, and the 3 principles of training for fitness?aerobic, muscular, flexibility