The Sleep of Skydivers: A Study of Stress

In this paper we report the results of a study in which we were able to assess the effects of a demonstrably stressful event—a sport parachute jump—on EEG recorded sleep. The sleep of 9 novice (one previous jump) and of 9 experienced (41 or more previous jumps) sport parachutists was monitored throughout the night for 4 nights prior to and for 1 night following the day during which a parachute jump had been scheduled to occur. A control group of sport parachutists who agreed not to make a jump during the course of their participation in the study were similarly seen for 5 consecutive nights. The results indicate that the execution, and to a lesser extent the anticipation, of the jump was stressful, especially for the novice group. However, the stressor induced only negligible changes in the sleep variables assessed. It is possible that there are critical differences in the effects on sleep of voluntarily imposed stresses and those which are commonly experienced in everyday life.