The single biggest mistake a lot of vertical jump athletes make is trying to over train. They want to learn How to Dunk so much that they are dedicated to do almost any amount of hard training regime to reach their goal.
How should you feel when you are properly training with quickness or plyometrics? You’re body should feel very good, your body should feel warm, and more energetic. And most importantly you should feel like you are jumping higher with each jump you take.