After an adrenaline rush, why do humans experience a sudden severe drop in energy? Would this not be disadvantageous for primitive survival?

Question

After an adrenaline rush, why do humans experience a sudden severe drop in energy? Would this not be disadvantageous for primitive survival?

In: Biology

Answer 1

For context: I was driving in the snow and almost lost control and narrowly avoided ending up in a ditch. Naturally, a huge adrenaline rush. A half hour into the drive later I was very drowsy, despite having drank a 5 hour energy just before leaving. This is not the first time this has happened either.