Adrenocortical Responses to Repeated Parachute Jumping and Subsequent h-CRH Challenge in Inexperienced Healthy Subjects

Impaired Memory Retrieval after Psychosocial Stress in Healthy Young Men

“…This is in line with previous studies in animals (de Quervain et al, 1998;Woodson et al, 2003) as well as with pharmacological studies in humans (de Quervain et al, 2000(de Quervain et al, , 2003Wolf et al, 2001a;Buss et al, 2004). Because pharmacological studies in humans induced free salivary cortisol levels in the upper physiological range [e.g., between 40 and 100 nmol/L (Deinzer et al, 1997)], it is remarkable that the moderate cortisol increases observed in the current stress study were also associated with a retrieval deficit. It is possible that the stronger adrenergic activation after psychosocial stress is partially responsible for this effect, because GCs appear to interact with adrenergic mechanisms in the amygdala and hippocampus in causing retrieval impairment (Roozendaal et al, 2004b).…”

State anxiety and cortisol reactivity to skydiving in novice versus experienced skydivers

“…Despite previous research supporting modulation of cortisol levels by skydiving in both of these groups, intuitively, we expected that there may have been some habituation of responding in the experienced group, leading to relatively higher cortisol levels in the novice group at the immediately post-jump time point. This hypothesis was also predicated by a previous finding by Deinzer et al [16], which suggested that cortisol reactivity to skydiving decreases by the third jump in individuals who undertake three skydives on the same day. However, no significant differences in cortisol reactivity were observed between the novice and experienced groups in the present study.…”

“…Similarly, although experienced skydivers also demonstrate post-jump increases in cortisol [15], no studies to date have compared novice versus experienced skydivers in relation to reactivity of the HPA axis. Deinzer and colleagues [16] have reported that when novice skydivers undertake three skydives on the same day, cortisol reactivity to the third jump is significantly lower than the reactivity to the first two jumps, suggesting that cortisol responses to skydiving may habituate with experience. However, it is uncertain whether this decline in the cortisol response across the day could be accounted for by i) the naturally occurring diurnal cortisol decline, ii) repeated activation of the HPA axis and the release of adrenal hormones within a relatively short period, and/or iii) higher cortisol levels earlier in the day resulting from an elevated cortisol awakening response due to anticipatory stress (i.e.…”

Heart rate variability and critical flicker fusion frequency changes during and after parachute jumping in experienced skydivers

“…These more accurate measurements of the time domain of HRV lead us to consider the hormonal response to be responsible for these. The cortisol response is indeed significant at the time of jump but clearly peaks after the jump as pointed out by many authors (Taverniers et al 2011;Hare et al 2013;Deinzer et al 1997).…”

“…Time between the different jumps, time of jumps and number of jumps in the day were not imposed since parachute jump, as an acute highly stressful event, has no anticipatory effect on autonomic modulation of the heart (Hynynen et al 2009). The ANS shows no acclimatization to repeated jumps (Allison et al 2012): a stress, such as parachute jumping, that induces strong adrenocortical responses does not necessarily affect subsequent cortisol responses to the same stress (Deinzer et al 1997).…”