Increase In Salivary Cortisol Research Articles

Consistently increased dorsolateral prefrontal cortex activity during the exposure to acute stressors.

Stress has a major impact on our mental health. Nonetheless, it is still not fully understood how the human brain responds to ongoing stressful events. Here, we aimed to determine the cortical dynamics during the exposure to ecologically valid, standardized stressors. To this end, we conducted 3 experiments in which healthy participants underwent the Trier Social Stress Test (experiments 1 and 2) and the Socially Evaluated Cold Pressor Test (experiment 3) or a respective control manipulation, while we measured their cortical activity using functional near-infrared spectroscopy. Increases in salivary cortisol and subjective stress levels confirmed the successful stress induction in all experiments. Results of experiment 1 showed significantly increased cortical activity, in particular in the dorsolateral prefrontal cortex, during the exposure to the Trier Social Stress Test. Experiment 2 replicated this finding and showed further that this stress-related increase in dorsolateral prefrontal cortex activity was transient and limited to the period of the Trier Social Stress Test. Experiment 3 demonstrated the increased dorsolateral prefrontal cortex activity during the Socially Evaluated Cold Pressor Test, suggesting that this increase is generalizable and not specific to the Trier Social Stress Test. Together, these data show consistently that dorsolateral prefrontal cortex activity is not reduced, as commonly assumed, but increased under stress, which may promote coping with the ongoing stressor.

Ventilation causing an average CO2 concentration of 1,000 ppm negatively affects sleep: A field-lab study on healthy young people

Poor bedroom ventilation, leading to poor indoor air quality (IAQ), has been shown to reduce sleep quality. Ventilation causing a carbon dioxide (CO2) concentration of 1,000 ppm is assumed to permit optimal sleep quality. The effects of three ventilation levels causing average indoor CO2 concentrations of 750 ppm, 1,000 ppm and 1,300 ppm, on sleep quality, physiological response and next-day work performance were examined. After a first night for adaptation, thirty-six young and healthy participants slept alone in simulated bedrooms for two nights at each of the three ventilation levels in balanced order. Sleep quality was recorded by a wrist-worn sleep tracker. Physiological parameters were measured before sleep and after waking. The participants’ ratings of the bedroom environment, the intensity of the health symptoms they experienced, and cognitive performance were obtained using questionnaires and tests.Compared with ventilation causing an average CO2 concentration of 750 ppm, sleep quality was significantly reduced at the ventilation rates causing CO2 concentrations of 1,000 ppm and 1,300 ppm: Sleep efficiency was reduced by 1.3 % and 1.8 % and time awake increased by 5.0 min and 7.8 min, respectively. Deep sleep duration decreased at the ventilation rate causing CO2 concentration of 1,300 ppm as compared to 750 ppm along with a significant increase in salivary cortisol after waking, which suggests increased stress and sympathetic activity. Ventilation causing an average CO2 concentration of 1,000 ppm or above in bedrooms should therefore be avoided. Participants whose sleep quality was poorer performed worse on tests of cognitive performance the next day.

Acute Social Stress Influences Moral Decision-Making Under Different Social Distances in Young Healthy Men.

Acute social stress has been shown to influence social decision-making. This study aimed to examine how social distance modulates the influence of acute social stress on young male moral decision-making. Sixty healthy male college students were randomly divided to be exposed to the Trier Social Stress Test (TSST) or a placebo version of the TSST (P-TSST) before they performed moral decision-making tasks. The results showed that participants under acute social stress showed obvious increases in subjective stress perception, negative affect, salivary cortisol, and alpha-amylase and made more altruistic choices for others compared to the control group. However, social distance regulates the promotion of this acute social stress, with the promotion effect being stronger in socially distant others. Furthermore, the interpersonal order difference of different social distances in altruistic decisions is smaller in low-conflict dilemmas than in high-conflict dilemmas. In addition, an increase in salivary cortisol was positively correlated with altruistic choices toward both acquaintances and strangers, whereas an increase in salivary alpha-amylase was only positively correlated with altruistic choices toward friends. The results suggest that social distance modulates the promotion of acute social stress on moral decision-making, which might stem from the divergent effects of cortisol and alpha-amylase.

Rapid effects of acute stress on cognitive emotion regulation

Acute stress has been shown to either enhance or impair emotion regulation (ER) performances. Besides sex, strategy use and stimulus intensity, another moderating factor appears to be timing of the ER task relative to stress exposure. Whereas somewhat delayed increases in the stress hormone cortisol have been shown to improve ER performances, rapid sympathetic nervous system (SNS) actions might oppose such effects via cognitive regulatory impairments. Here, we thus investigated rapid effects of acute stress on two ER strategies: reappraisal and distraction. N = 80 healthy participants (40 men & 40 women) were exposed to the Socially Evaluated Cold-Pressor Test or a control condition immediately prior to an ER paradigm which required them to deliberately downregulate emotional responses towards high intensity negative pictures. Subjective ratings and pupil dilation served as ER outcomes measures. Increases in salivary cortisol and cardiovascular activity (index of SNS activation) verified successful induction of acute stress. Unexpectedly, stress reduced subjective emotional arousal when distracting from negative pictures in men indicating regulatory improvements. However, this beneficial effect was particularly pronounced in the second half of the ER paradigm and fully mediated by already rising cortisol levels. In contrast, cardiovascular responses to stress were linked to decreased subjective regulatory performances of reappraisal and distraction in women. However, no detrimental effects of stress on ER occurred at the group level. Yet, our findings provide initial evidence for rapid, opposing effects of the two stress systems on the cognitive control of negative emotions that are critically moderated by sex.

Interactive teaching enhances students' physiological arousal during online learning

The pure transfer of face-to-face teaching to a digital learning environment can be accompanied by a significant reduction in the physiological arousal of students, which in turn can be associated with passivity during the learning process, often linked to insufficient levels of concentration and engagement in the course work. Therefore, the aim of this study was to investigate whether students' psychobiological stress responses can be enhanced in the context of anatomical online learning and how increased physiological parameters correlate with characteristics of learning experiences in a digital learning environment. Healthy first-year medical students (n = 104) experienced a regular practical course in Microscopic Anatomy either in face-to-face learning, in passive online learning or in an interaction-enhanced version of online learning. Compared to passive online learning, students engaged in the interaction-enhanced version of online learning displayed a significantly reduced Heart Rate Variability (P 0.001, partial η2 = 0.381) along with a strong increase in salivary cortisol (P 0.001, partial η2 = 0.179) and salivary alpha-amylase activity (P 0.001, partial η2 = 0.195). These results demonstrated that the physiological arousal of students engaged in online learning can be enhanced via interactive teaching methods and pointed towards clear correlations between higher physiological responses and elementary criteria of learning experience such as engagement and attention.

Stress-induced HPA activation in virtual navigation and spatial attention performance

BackgroundPrevious research has shown that spatial performance (e.g. navigation, visuospatial memory, attention) can be influenced by acute stress; however, studies have produced mixed findings sometimes showing an improvement after stress, other times showing impairment or no overall effect. Some of these discrepancies may be related to: the type of stress system activated by the stressor (sympathetic adrenal medulla [SAM] or hypothalamic-pituitary-adrenocortical [HPA]); whether cortisol responders vs. nonresponders are analyzed subsequent to main effects; and sex differences in stress responses. In the present study, we examine the influence of HPA activation from an acute laboratory stressor (Socially Evaluated Cold Pressor test [SECPT]) on performance during two spatial tasks: Useful Field of View (UFOV; a measure of spatial attention) and virtual reality (VR) navigation. We assigned 31 males and 30 females to either the SECPT or a Non-Stress condition prior to the two spatial tasks. Cardiovascular measures including heart rate and blood pressure, and salivary cortisol biosamples were obtained at specific time points.ResultsParticipants in the Stress condition showed increases in heart rate, systolic and diastolic blood pressure indicating sympathetic adrenal medulla (SAM) axis activation. Stress also led to increases in salivary cortisol, suggesting hypothalamic-pituitary-adrenocortical (HPA) activation. Stress did not influence overall performance in the spatial attention UFOV or the VR navigation task. However, a sex difference in spatial attention was detected when participants were divided into Stress-cortisol responders and non-responders in the UFOV task. Male Stress-cortisol responders (n = 9) showed better UFOV accuracy than female Stress-cortisol responders (n = 6); no sex differences were found among the Non-Stress control group. Furthermore, for females in the stress condition (n = 14), higher cortisol responses were associated with lower spatial attention performance.ConclusionsSocially Evaluated Cold Pressor stress resulted in no change in speed or accuracy in a VR navigation task. For the spatial attention task, the SECPT led to a sex difference among Stress-cortisol responders with males showing improved accuracy over females. The relationship between HPA activation and prefrontal cortex activity may be necessary to understand sex differences in spatial attention performance.

Opioid-blunted cortisol response to stress is associated with increased negative mood and wanting of social reward

Animal research suggests a central role of the μ-opioid receptor (MOR) system in regulating affiliative behaviors and in mediating the stress-buffering function of social contact. However, the neurochemistry of stress-related social contact seeking in humans is still poorly understood. In a randomized, double-blind, between-subjects design, healthy female volunteers (N = 80) received either 10 mg of the µ-opioid agonist morphine sulfate, or a placebo. Following a standardized psychosocial stress induction, participants engaged in a social reward task, in which the motivation to obtain skin-to-skin social touch and the hedonic reactions elicited by such touch were assessed. Morphine prevented the increase of salivary cortisol typically observed following acute stress exposure. Notably, this altered HPA axis responsivity was associated with increased negative affect in response to psychosocial stress, and with enhanced subjective wanting of highly rewarding social contact. These findings provide novel evidence on the effect of exogenous opioids administration on the reactions to psychosocial stress and point to a state-dependent regulation of social motivation.

Lactobacillus rhamnosus CNCM I-3690 decreases subjective academic stress in healthy adults: a randomized placebo-controlled trial

ABSTRACT Psychological stress negatively affects the intestinal barrier function in animals and humans. We aimed to study the effect of Lactobacillus rhamnosus CNCM I-3690 on intestinal permeability and stress-markers during public speech. Healthy students were randomized to L. rhamnosus-containing (test) or acidified (placebo) milk consumed twice daily for 4 weeks, with 46 subjects per treatment group. Small intestinal permeability was quantified by a 2 h urinary lactulose–mannitol ratio (LMR, primary outcome), fractional excretion of lactulose (FEL) and mannitol (FEM). Salivary cortisol, State-Trait Anxiety Inventory (STAI) and Perceived Stress scores (PSS) were collected. No between-treatment differences were found for LMR (p = .71), FEL or FEM. Within-treatment analyses showed similar LMR and FEL but a stress-induced increase of FEM with the placebo (p < .05) but not test product. Despite a similar increase in salivary cortisol, the stress-induced increase in STAI was significantly lower with the test product vs. placebo (p = .01). Moreover, a stress-preventative effect of the probiotic was found for PSS and more pronounced in subjects with high stress-induced cortisol (p = .01). While increased FEM was mediated by salivary cortisol levels, the effect of the test product on subjective stress was not mediated by changes in FEM. No serious adverse events occurred. In conclusion, we demonstrated that L. rhamnosus CNCM I-3690 prevented stress-induced hyperpermeability to mannitol. Subjective but not objective stress-markers were reduced with L. rhamnosus vs. placebo, suggesting anxiolytic effects, which were independent of barrier stabilization and attractive for the reduction of stress in both health and disease. Clinicaltrials.gov, number NCT03408691.

Biomarkers of Stress and Male Fertility.

To study if stress, as measured by salivary alpha-amylase and cortisol, negatively impacts male fertility, as measured by semen parameters, pregnancy, and live birth rates. Prospective, cohort study of men enrolled in the Males, Antioxidants, and Infertility (MOXI) trial. One-hundred twelve infertile men provided first-morning salivary and semen samples at baseline. Salivary samples were analyzed for alpha-amylase and cortisol. Couples attempted to conceive naturally (months 1-3) and with clomiphene citrate/intrauterine insemination (months 4-6). The association between stress-related biomarkers and semen parameters including DNA fragmentation was assessed using linear regression models adjusting for male age. Salivary levels were dichotomized at the 80th percentile. Pregnancy/live birth rates in couples in the upper quintile were compared to remaining subjects using chi-square testing. Salivary levels of alpha-amylase were not associated with semen parameters or DNA fragmentation. Salivary cortisol levels were not correlated with DNA fragmentation or normal morphology. For every 1-unit increase in salivary cortisol, total sperm count increased by 13.9 million (95% CI: 2.5, 25.3) and total motile sperm count increased by 9.9 million (95% CI: 3.2-16.6). Couple pregnancy rates and live birth rates did not differ for males in the highest quintile of alpha-amylase (27% and 28%, p = 0.96; 23% and 21%, p = 0.87) or cortisol (40% and 26%, p = 0.22; 35% and 19%, p = 0.12), compared to males with lower values. Physiologic measures of high stress may not harm but actually improve semen parameters among men with male-factor infertility.

Sampling methods for determination of cortisol in pig saliva and their use in the assessment of pig welfare

This study focused on finding new information regarding the assessment of pig saliva cortisol samples in terms of practical effects of the sampling, sample storage conditions, and their laboratory analysis. The study was divided into two experiments. The first experiment was focused on finding the effect of sampling time on cortisol concentrations in pig saliva. The second experiment was focused on determining the effect of storage conditions on the value of salivary cortisol. Before the initiation of the study, we tested which one of the commercially available ELISA kits would be the most suitable for our experiments. Simultaneously, we carried out a pre-study to evaluate the effect of relocation and change in the housing type on the concentration of salivary cortisol in gestating sows. The samples were obtained by oral cavity swabbing, using a standard cotton swab. In the first study, piglets were examined at the age of 4 ± 1 days, and breeding management routine procedures were used as a stress factor. In the second study, the piglets were examined immediately after weaning (at 28 ± 2 days of age). The Cortisol EIA kit was found to be statistically more accurate and thus a more suitable ELISA kit for our experiment. Analysis of the relocation effect and the effect of change in the housing type showed that relocation does not seem to be a stress factor for gestating sows as no significant changes were observed in salivary cortisol concentration (P &gt; 0.5); however, the change in the housing type lead to a significant increase in salivary cortisol (P &lt; 0.001). In the first study, we determined using the ELISA method that the most significant difference occurred in 40 min (P &lt; 0.01), which suggests that the best time for a sampling in order to assess salivary cortisol concentration is 40 min after stress induction by routine procedures. The conclusion of the second study was that in the monitored period of 60 h (P &lt; 0.05), cortisol concentration decreased depending on the storage temperature. The decrease started between 48 and 60 h which showed that cortisol is stable in the saliva sample for at least 48 h. These findings will be further applied in our following studies focused on assessment of salivary cortisol concentration after stress induction.

Individual variation in diurnal cortisol in patients with knee osteoarthritis: Clinical correlates

BackgroundThe cortisol awakening response (CAR) is a core biomarker of hypothalamic-pituitary-adrenal (HPA) axis regulation. To date, however, studies of HPA-axis function among patients with chronic pain are scarce and show equivocal results. The objectives of this study were to investigate the association between CAR and pain-related outcomes and to investigate potential sex differences in patients with knee osteoarthritis (KOA). MethodsIn this cross-sectional study, KOA patients (N = 96) completed self-report questionnaires assessing pain and psychosocial factors and underwent Quantitative Sensory Testing (QST) to assess pressure pain threshold (PPT). Additionally, salivary cortisol samples (N = 60) were collected to assess HPA-axis function at 6 time points (awakening, 15- and 30-minute post-awakening, 4 PM, 9 PM and bedtime). The CAR was calculated by examining increases in salivary cortisol from awakening to 30 min post awakening and the total post-awakening cortisol concentration by calculating the lower areas under the curve of cortisol with respect to ground (AUCG). ResultsPatients with a relatively blunted CAR had significantly higher anxiety levels and lower PPT than patients with relatively normal CAR. Similarly, patients with a relatively reduced AUCG had significantly higher pain interference and anxiety levels compared to patients with relatively normal AUCG. PPT was positively correlated with CAR and AUCG and negatively correlated with pain severity and anxiety. Men with KOA had significantly lower anxiety, higher PPT and higher CAR and AUCG than women with KOA. Mediation analysis results revealed a significant indirect effect of PPT on the relationship between sex and AUCG. ConclusionsThe findings of this study suggest that neuroendocrine factors such as CAR and AUCG may contribute to individual differences in pain-related outcomes in patients with KOA. Additionally, our results show sex differences in the magnitude of morning HPA activation and pain-related outcomes. Finally, our findings are suggestive of a sex-dependent relationship between post-awakening cortisol concentrations and pain perception. Future research should examine these associations across various pain populations.

Stress-induced bias of multiple memory systems during retrieval depends on training intensity

Stressful events promote a shift from hippocampus-dependent ‘cognitive’ learning towards dorsal striatum-dependent ‘habit’ learning. Beyond modulating the recruitment of multiple memory systems during learning, recent evidence suggests that stress may also affect which of these memory systems is employed during retrieval, thereby affecting the nature of remembering. However, while some studies reported increased reliance on ‘habit’ memory retrieval after stress, other studies suggested even a bias towards ‘cognitive’ memory retrieval after stress. In the present experiment, we tested the hypothesis that the nature of the stress effect on the control of memory retrieval depends on the extent of initial training. To this end, participants completed a probabilistic classification learning (PCL) task that can be solved by both the ‘cognitive’ and the ‘habit’ memory systems, which is reflected in the engagement of specific behavioral strategies. Critically, participants received either moderate (100 trials) or intensive (200 trials) training in the PCL task. Participants then underwent a stress protocol or a non-stressful control procedure, before they completed a retrieval version of the PCL task. The effectiveness of the stress manipulation was verified by increases in salivary cortisol and autonomic arousal. Our results further revealed that participants who received moderate training showed, during retrieval, a stress-induced shift towards strategies indicative of the dorsal striatal ‘habit’ memory system. After prolonged training, however, stress did not affect which memory system guided retrieval. The present results indicate that the effect of stress on the engagement of multiple memory systems during retrieval is critically dependent on the extent of initial training and, by inference, on the strength of the multiple memory traces established during learning.

Postural Control and Stress Exposure in Young Men: Changes in Cortisol Awakening Response and Blood Lactate.

Background: It has recently been noticed that the quantity of stress affects postural stability in young women. The study was conducted with the goal of investigating whether increased stress may damagingly effect posture control in 90 young men (71 right-handed and 19 left-handed) while maintaining an upright bipedal posture, while keeping their eyes open or closed. Perceived Stress Scale (PSS) was administered and changes in free cortisol levels were monitored (Cortisol Awakening Response, CAR) in order to evaluate the amount of stress present during awakening, while the Profile of Mood States (POMS) was used to estimate distress on the whole. Posture control was evaluated with the use of a force platform, which, while computing a confidence ellipse area of 95%, was engaged by the Center of Pressure through five stability stations and was sustained for a minimum of 52 s, with and without visual input. Another goal of the experiment was to find out whether or not cortisol increases in CAR were linked with rises of blood lactate levels. Results: CAR, PSS and POMS were found to be extensively related. Furthermore, it has been observed that increases in salivary cortisol in CAR are associated with small but significant increases in blood lactate levels. As expected, stress levels did affect postural stability. Conclusions: The results of the present study confirm that the level of stress can influence postural stability, and that this influence is principally obvious when visual information is not used in postural control.

Aerodynamic and Acoustic Voice Measures Before and After an Acute Public Speaking Stressor.

Purpose The goal of this study was to determine if differences in stress system activation lead to changes in speaking fundamental frequency, average oral airflow, and estimated subglottal pressure before and after an acute, psychosocial stressor. Method Eighteen vocally healthy adult females experienced the Trier Social Stress Test (TSST) to activate the hypothalamic-pituitary-adrenal axis. The TSST includes public speaking and performing mental arithmetic in front of an audience. At seven time points, three before the stressor and four after the stressor, the participants produced /pa/ repetitions, read the Rainbow Passage, and provided a saliva sample. Measures included (a) salivary cortisol level, (b) oral airflow, (c) estimated subglottal pressure, and (d) speaking fundamental frequency from the second sentence of the Rainbow Passage. Results Ten of the 18 participants experienced a hypothalamic-pituitary-adrenal axis response to stress as indicated by a 2.5-nmol/L increase in salivary cortisol from before the TSST to after the TSST. Those who experienced a response to stress had a significantly higher speaking fundamental frequency before and immediately after the stressor than later after the stressor. No other variable varied significantly due to the stressor. Conclusions This study suggests that the idiosyncratic and inconsistent voice changes reported in the literature may be explained by differences in stress system activation. In addition, laryngeal aerodynamic measures appear resilient to changes due to acute stress. Further work is needed to examine the influence of other stress systems and if these findings hold for dysphonic individuals.

Acute stress amplifies experienced and anticipated regret in counterfactual decision-making

Previous research has shown that stress can affect emotion processing in a variety of settings. However, little attention has been paid to the effects of stress on emotional decision-making. The present study addressed this question by exposing healthy young participants either to a stressor (n = 30)–socially evaluated cold pressor task– or a non-stressful control task (n = 30). Subsequently, participants completed a computerized decision-making task in which they could compare the obtained factual outcome with a non-obtained counterfactual outcome. Saliva samples were taken at four time points over the course of the experiment and used to analyze cortisol levels. Results revealed that acute stress induced reliable salivary cortisol increase over the experimental task. At the outcome delivery stage, acute stress amplified negative emotions induced by the counterfactual comparison. At the choice stage, under stress, participants were more likely to make regret-averse decisions. The findings that acute stress amplifies both experienced and anticipated regret is consistent with dual process frameworks such that stress tilts decision-making toward more emotional and intuitive processing. Lay summary Stress is thought to affect emotional processing. The present study investigated the effects of acute stress on emotional decision making using a typical counterfactual decision making task. Acute stress amplified both experience and anticipation of regret, consistent with the dual process frame that stress tilts decision-making toward more emotional and intuitive processing.

Is it getting in the hair? – Cortisol concentrations in native, regrown and segmented hairs of cattle and pigs after repeated ACTH administrations

Adrenocorticotropic hormone (ACTH) is part of the hypothalamic-pituitary-adrenal axis response to stress and induces the release of cortisol, which is commonly used as an indicator in stress and animal welfare research. In recent years, hair cortisol concentration (HCC) gained increasing importance as a promising retrospective indicator for stress in animals. Thus, the aim of our study was to validate HCC as a potential indicator of increased endogenous cortisol release in cattle and pigs by repeated ACTH administrations followed by cortisol analysis in different hair types. For this purpose, 34 cattle and 38 gilts were treated either with repeated i.m. injections of ACTH or saline every second day over a period of 4 weeks. Saliva samples were taken before and after injections once a week from selected animals to verify the endogenous cortisol response. At the end of the treatment (week 4) and after 8 and 12 weeks, samples of natural and regrown hair were taken from the caudo-dorsal region of the back and analyzed for cortisol concentrations. In addition, natural hair was sampled after 12 weeks and cut into segments prior to analysis. Treatment with ACTH revealed a significant increase in salivary cortisol after application in both species, although this increase was attenuated in pigs compared to cattle. In week 4, HCCs were significantly elevated in natural and regrown hair of ACTH-treated animals. In cattle, HCCs significantly increased after ACTH treatment in natural, regrown and segmental hair compared with control animals, indicating that HCC may be a promising indicator of stress, as cortisol levels in all hair types reflected the preceding period with increased cortisol release. In pigs, there were no differences in HCCs between treatments. This may be caused by the lower systemic cortisol response in pigs, but seasonally reduced hair growth and external cross-contamination of hair by saliva and urine under commercial husbandry conditions may also interfere with the validity of HCC in this species.

Stress-Induced Increase in Cortisol Negatively Affects the Consolidation of Contextual Elements of Episodic Memories.

Stress can modulate episodic memory in various ways. The present study asks how post-encoding stress affects visual context memory. Participants encoded object images centrally positioned on background scenes. After encoding, they were either exposed to cold pressure stress (CPS) or a warm water control procedure. Forty-right hours later, participants were cued with object images, and for each image, they were asked to select the background scene with which it was paired during study among three highly similar options. Only male but not female participants reacted with a significant increase in salivary cortisol to CPS, and the stress and control group did not differ in recognition performance. Comparing recognition performance between stress responders and non-responders, however, revealed a significant impairment in context memory in responders. Additionally, proportional increase in cortisol was negatively correlated with the number of correctly recognized scenes in responders. Due to the small number of responders, these findings need to be interpreted with caution but provide preliminary evidence that stress-induced cortisol increase negatively affects the consolidation of contextual elements of episodic memories.

PHYSIOLOGICAL AND ANXIETY RESPONSES TO SOCIALLY PRESCRIBED PERFECTIONISM FOR GYMNASTIC COMPETITION: CASE STUDY

The purpose of this study was to analyze the psychophysiological responses (anxiety, cortisol, heart rate, skin conductance) to acute psychological stress during a visualization of competition, under the influence of pressure for perfection exerted by parents, and pressure for perfection exercised by the coach. Artistic gymnasts (3 men and 3 women) with an age range of 13 to 15 years participated, who were present in four sessions for data collection that included salivary cortisol, heart rate and skin conductance. The first session was the baseline, where we apply a booklet of questionnaires that inquire about competitive anxiety and pressure for perfection. The remaining three sessions included guided viewing; session two to create mental images and live the gymnastic competition; the third highlights the pressure for perfection created by the coach (PPE); and the fourth highlights the pressure for perfection created by parents (PPP). The results showed that the visualization of competitive situation causes stress and anxiety, although the increase in salivary cortisol was within the normal daytime level. The physiological changes were greater in those gymnasts who perceived high PPE and PPP. However, for some gymnasts the situation was considered threatening (decrease in skin conductance, and small increases in heart rate), and for others was challenging (increase in skin conductance and heart rate). In conclusion, the pressure for perfection integrates a link for the different physiological responses in competition.

Renin-angiotensin system in stress response and the effect of chronic exercise in healthy volunteers

Aim: Stress is a multidisciplinary field of research. Renin-angiotensin system (RAS) components have been shown to be involved in stress. Exercise also can be considered as a stress factor. The aim of this study was to investigate the RAS components and effect of chronic exercise on stress response in a prospective design. Material and Methods: Twenty healthy volunteers were recruited to the study. Trier psychosocial stress test was used to simulate psychosocial stress. Blood pressure, heart rate, plasma renin activity and angiotensin II, salivary cortisol were measured. Subjective stress perception is assessed. Results: Blood pressure, plasma renin activity (PRA), Angiotensin II (Ang II) increased with the stress test. There was no statistically significant increase in salivary cortisol and heart rate levels with Trier social stress test (TSST) both before and after exercise. Self-ratings of the exercise adherence ratio were high as 72%.Conclusion: Monitoring for a longer duration of time after stress can better explain stress response and RAS.

Investigation of the Relationship Between Salivary Cortisol, Training Load, and Subjective Markers of Recovery in Elite Rugby Union Players.

Insufficient recovery can lead to a decrease in performance and increase the risk of injury and illness. The aim of this study was to evaluate salivary cortisol as a marker of recovery in elite rugby union players. Over a 10-wk preseason training period, 19 male elite rugby union players provided saliva swabs biweekly (Monday and Friday mornings). Subjective markers of recovery were collected every morning of each training day. Session rating of perceived exertion (sRPE) was taken after every training session, and training load was calculated (sRPE × session duration). Multilevel analysis found no significant association between salivary cortisol and training load or subjective markers of recovery (all P > .05) over the training period. Compared with baseline (wk 1), Monday salivary cortisol significantly increased in wk 4 (14.94 [7.73]ng/mL; P = .04), wk 8 (16.39 [9.53]ng/mL; P = .01), and wk 9 (15.41 [9.82]ng/mL; P = .02), and Friday salivary cortisol significantly increased in wk 5 (14.81 [8.74]ng/mL; P = .04) and wk 10 (15.36 [11.30]ng/mL; P = .03). The significant increase in salivary cortisol on certain Mondays may indicate that players did not physically recover from the previous week of training or match at the weekend. The increased Friday cortisol levels and subjective marker of perceived fatigue indicated increased physiological stress from that week's training. Regular monitoring of salivary cortisol combined with appropriate planning of training load may allow sufficient recovery to optimize training performance.