Effects of emotional stress on neuroendocrine and autonomic functions in skydiving

By using a psycho-physiological approach we investigated the stress response during parachute jumping, a wellcharacterized stress model to study emotional and physical stress in humans. Besides the observation of hormone reactivity in response to such a short-term stressful event, this study focused on the correlations among competitive state anxiety components, hormonal and autonomic responses. Seven male sport-parachutists, aged 35.7 ± 17.5 years, took part in the study after giving their informed consent. Neuroendocrine and autonomic variables were measured 12 h before jumping (basal), within 60 s (jump) and 90 min after touching the ground (post-jump). Prior to boarding, participants were administered the Competitive State Anxiety Inventory-2 (CSAI-2) questionnaire. Salivary cortisol (Cort) and a-amylase (A-A) concentrations were measured by spectrophotometry using commercial kits. For heart rate (HR) and galvanic skin response (GSR) assessments data were acquired by holter recording, within an interval time of 5 min following saliva collection. Parachute jumping led to a strong response of Cort, A-A, as well as HR and GSR, as shown by the values noted as basal and at jump, meaning that the psychological arousal linked to this condition acts on different systems. In examining bioumoral correlates and psychological measures of stress and anxiety we found correlations between neuroendocrine parameters and anxiety components. However, no relationship between Cort and somatic or cognitive anxiety was noted, suggesting that this physiological measure is not a good index of stress during parachuting. As revealed by the differences in cognitive or somatic state anxiety, stress related to sport parachuting differentially affected salivary indices. Alpha-amylase seems to be a better physiological indicator than cortisol to examine the relationship between neuroendocrine parameters and state anxiety components. Finally, this is the first report that GSR significantly correlated with A-A and the somatic component of competitive state anxiety, confirming its potential to provide researchers with a tool for objectively measuring stress during operational conditions. On the whole, these findings have contributed to our understanding of hormone-behavior relationships.