Rapidly returning body temperature to normal after exercise is associated with spikes in growth hormone release.

“and then the other interesting thing was that even after the exercise taking body temperature back down to normal levels relatively quickly seemed to be associated with these big spikes in growth hormone otherwise what would happen is you get these big spikes in growth hormone but if the exercise went too long or if body temperature remained too high for too long then you didn't get the second increase in growth hormone the following night”