Cortisol and affective responses to exercise

The acute effect of respiratory muscle training on cortisol, testosterone, and testosterone-to-cortisol ratio in well-trained triathletes - exploratory study

The study investigated acute changes in cortisol (C) and testosterone (T) associated with a popular RMT method, voluntary isocapnic hyperpnoea (VIH), in well-trained triathletes. 19 athletes (7 females, 12 males) performed a VIH training session with pre- and post- serum C and T measurements. Repeated measures ANOVA was employed to analyze hormone changes during VIH, with additional time-sex interaction. Pearson correlation coefficient has been computed to identify the relationship between hormonal changes and age, anthropometric indices, respiratory muscle strength, and training experience. There was a statistically significant effect for C changes (F = 13.101, p = 0.002, ηp2 = 0.421, ω2 = 0.08). The C concentration was significantly lower after VIH (Mean Difference = -32.49 ± 39.13 nmol*L-1). No significant effects for T, T/C ratio, and time-sex interactions were observed (p > 0.05). Amongst many, significant correlations between the percentage of body fat and changes in C (r=-0.464, p=0.045), body mass and changes in T (r=0.516, p=0.024), height and changes in T (r=0.509, p=0.026) were found. VIH significantly lowered C concentration. No significant effects for T, T/C ratio, and no between-sex differences were observed. Noteworthy individual variability was observed in all the monitored indices. Significant correlations were found between acute hormone changes associated with VIH and selected anthropometric indices. The study provides initial insight into VIH's role in athletes' hormonal balance to possibly guide exercise prescription, autoregulation, arousal state management, and recovery practices in athletes.

A Relaxed Horse-A Relaxed Client? An Experimental Investigation of the Effects of Therapy Horses' Stress on Clients' Stress, Mood, and Anxiety

Equine-assisted therapies are becoming increasingly popular for addressing physical and psychological disabilities in clients. The role of the horse's welfare in equine-assisted service receives increasing attention in research. Several studies have shown that horses are able to perceive human emotions and respond to human stress responses. However, no research has yet looked at the other side of the coin-whether and how humans perceive and react to equine stress levels during equine-assisted services. To fill this gap in the research, we employed a within-subjects design, in which horse-naïve participants had a standardized interaction with both an experimentally stressed horse and an experimentally relaxed horse. We assessed physiological indicators of stress (heart rate, heart rate variability, and salivary cortisol) in participants and horses, as well as psychological indicators of stress (state anxiety and positive and negative affect) in participants. Although our stress and relaxation manipulations were successful (indicated by horses' physiological indicators of stress), we did not find any difference in the participants' physiological or psychological indicators of stress between the interaction with a stressed and the interaction with a relaxed horse. Together with results from previous studies, this suggests that humans cannot intuitively recognize the (physiological) stress level of horses, which has important implications for effective communication and bonding between humans and horses and for the safety of equine activities.

Differential effects of acute exercise on emotional memory in men and women

Exercise may change emotional memory, which is associated with the induction of mental disorders such as depression and anxiety. This effect of exercise may be influenced by exercise-induced cortisol release. Depending on sex, cortisol exerts differential effects on emotional memory consolidation. However, whether acute exercise and exercise-induced cortisol release have sex-dependent effects on emotional memory has not been established. Therefore, first, we aimed to determine the effects of acute exercise on emotional memory, separately for men and women, in a within-subjects design. Second, we aimed to examine whether the effects of acute exercise on emotional memory are related to the effects of exercise-induced cortisol release, separately for men and women. Sixteen healthy men and 15 healthy women were presented with positive and negative emotional images, followed by either rest or a vigorous-intensity cycling exercise condition using a within-subjects design on separate days. Salivary cortisol was measured before presenting the emotional images presentation and 20 min after each intervention. Emotional memory was assessed two days later. Vigorous-intensity exercise decreased emotional memory in women, whereas there was no change in men after rest or exercise. Cortisol levels increased after exercise intervention in both men and women, although there was no association between cortisol levels and emotional memory. These findings demonstrate that the effect of a single bout of vigorous-intensity exercise on emotional memory differs between men and women and is associated with decreased emotional memory in women.

PE augmented mindfulness: A neurocognitive framework for research and future healthcare

Various well-controlled studies have suggested that practitioners in mindfulness can be prone to patient drop-out (e.g., due to chronic stress, pathology, cognitive reactivity), despite researchers having identified the underlying mechanisms that link mindfulness to mental health. In this article, a framework for physical exercise (PE) augmented mindfulness is proposed, which posits that consistently practiced PE before meditation can support (early-stage) mindfulness. Neurocognitive research shows PE (aerobic exercises or yoga) and mindfulness to impact similar pathways of stress regulation that involve cognitive control and stress regulation, thereby supporting the proposed synergistic potential of PE augmented mindfulness. Research focused on the psychophysiological impact of PE, showed its practice to promote short-term neurocognitive changes that can promote both cognitive control and the attainment of mindful awareness (MA). In order to chart dose responses required for protocol development, further research will be presented. Together these findings are discussed in light of future research on this multidisciplinary topic, protocol development, mindful walking, and further application in healthcare and beyond.

Effect of Exercise on Fatigue in Patients with Lung Cancer: A Systematic Review and Meta-Analysis of Randomized Trials

Background: Fatigue is a frequent debilitating symptom among patients with lung cancer. The effect of exercise on fatigue remains to be quantified. Objective: This review aimed to examine the effect of exercise on fatigue by synthesizing findings from randomized controlled trials (RCTs). Methods: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was conducted in five electronic databases from inception to March 2020. Only RCT was included. The primary outcome was fatigue and the secondary outcomes included depression, anxiety, quality of life, and functional capacity. Pooled weighted or standardized mean difference (WMD or SMD) with 95% confidence interval (CI) was calculated. Results: Eight RCTs were included. The exercise intervention was delivered in the supervised environment (n = 6) or free-living settings (n = 2). Exercise reduced the level of fatigue (SMD = -0.33; 95% CI = -0.54 to -0.13). Exercise also decreased depressive symptom (WMD = -1.57; 95% CI = -2.69 to -0.44) and anxiety (WMD = -1.39; 95% CI = -2.60 to -0.18). Exercise showed a moderate effect on the quality of life, with an SMD of 0.33 (95% CI = 0.08 to 0.58). Exercise intervention increased functional capacity as measured by the six-minute walk test by 20 meters (95% CI = 14.2 to 55.0), but the effect was not significant (p = 0.247). Conclusion: Exercise demonstrated a moderate effect on fatigue in patients with lung cancer. Exercise also improved depressive symptoms, anxiety, and quality of life; however, its impact on functional capacity was not significant. More clinical trials are warranted to explore the mechanisms underlying the impact of exercise on fatigue. Strategies improving adherence to exercise prescription should be developed to help these patients overcome potential challenges.

Effects of exercise before and/or after a mixed lunch on postprandial metabolic responses in healthy male individuals

PURPOSE

Exercise plays an important role in preventing and treating postprandial dysmetabolism. We investigated the postprandial metabolic responses to a standard lunch when a session of aerobic exercise is performed in the early postprandial phase or divided between the pre- and postprandial period.

METHODS

Nine healthy volunteers consumed a standardised mixed lunch and rested for the following 3 h (Con) or performed 40 min of cycling at 65% V̇O₂max after lunch (CPPEx), or two 20-min sessions, one before (SplitEx1) and the other after lunch (SplitEx2), at the same intensity.

RESULTS

At 1-h post-lunch, a significant reduction (P < 0.001) in glycaemia was observed for CPPEx (- 25 ± 10%) and SplitEx (- 34 ± 7%) compared to Con. Yet, a post-exercise rebound lessened the exercise effect on the glycaemic area under the curve (AUC) at 2 and 3 h. At 1 h, a significant reduction (P < 0.009) in plasma insulin (SplitEx - 53 ± 31%; CCPEx - 48 ± 20%) and C-peptide (SplitEx - 57 ± 20%; CCPEx - 47 ± 24%) was observed compared to Con. Glucose-dependent insulinotropic polypeptide (GIP) increased after the meal, without differences between conditions. Compared with SplitEx1, cortisol response was attenuated during SplitEx2 and CPPEx. At 3 hours, triglyceride AUC was significantly higher (P = 0.039) in SplitEx compared to Con (+ 19 ± 8%).

CONCLUSION

Forty minutes of postprandial exercise or 20 min of pre- and postprandial exercise are both effective at attenuating the glycaemic and insulinaemic response to a mixed lunch, while a higher lipaemia was found in the pre- and postprandrial exercise condition.

Long-Term Effect of an Exercise Training Program on Physical Functioning and Quality of Life in Pulmonary Hypertension: A Randomized Controlled Trial

The aim of this study was to evaluate the effects of a 6-month combined aerobic and strength exercise training program on functional and psychological aspects and health-related quality of life in patients with PH and to evaluate its longer-term impact. In total, 22 stable patients (mean age 53.9 ± 13.8, 13 female) with pulmonary hypertension of World Health Organization (WHO) class I-III participated in a nine-month study. They were randomly assigned into two groups: Group A participated in a 6-month combined aerobic and strength exercise training program, whereas Group B remained untrained. All patients underwent physical and psychological assessment at baseline and at month 6 (after completing the exercise program) and physical assessment after 9 months (3 months posttraining). After the 6-month exercise training program, patients of Group A significantly improved their physical (6MWD, STS 10 rep, STS 20 rep, TUG, lower limb strength, cardiopulmonary exercise time, METs, peak VO₂, VCO₂, and VE/VCO₂ slope) and psychological aspects (SF-36, STAI, and BDI). Between the two groups, differences were observed at the 6MWD (95% CI: 36.2-64.6, η² = 0.72), STS 10 rep (95% CI: 6.6-2.2, η² = 0.4), STS 20 rep (95% CI: 10.8-2.4, η² = 0.34), lower limb strength (95% CI: 7.2-3.6, η² = 0.38), cardiopulmonary exercise time (95% CI: 0.1-3.3, η² = 0.2), and VCO₂ (95% CI: 0.1-0.5, η² = 0.2). Additionally, psychological changes were noted at SF-36, PCS (95% CI: 3.6-14.8, η² = 0.35), MCS (95% CI: 1.3-16.1, η² = 0.22), TCS (95% CI: 1.3-16.1, η² = 0.22), and STAI (95% CI: 1.8-28.2, η² = 0.18). The favorable results of exercise were maintained at the 3-month posttraining follow-up assessment. No exercise-induced complications were observed throughout the study. In conclusion, a long-term exercise training program is a safe and effective intervention to improve functional status, psychological aspects, and health-related quality of life in patients with PH.

Assessment of feasibility and outcomes of a salivary cortisol collection protocol in five American Indian communities

We evaluated the feasibility and outcomes of administering a naturalistic saliva collection procedure and assessment in American Indian (Indigenous) communities. We focus on Indigenous adults living with type 2 diabetes given the "epidemic" of the disease disproportionately impacting many tribal groups. Data are from community-based participatory research (CBPR) involving 5 tribal communities. Participants were randomly selected from tribal clinic records. The sample includes 188 adults living with type 2 diabetes (56% female; age range = 18-77 years; M age = 46.3 years). Participants provided a total of 748 saliva samples, representing 4 samples/participant on a single day with instructions for collection at 4 time points: upon waking, 1 h after waking, 2 h after waking, and at 8 PM. Saliva sample times were recorded by participants on paper and electronically via placement in a Medication Event Monitoring System (MEMS®) bottle. Overall, 67% of samples were completed within 10 min of protocol instructions and 91% of participants provided at least one useable sample (79% provided four useable samples). Noncompliance, behavioral and environmental factors were not robustly associated with deviations in observed cortisol indices. Results suggest that home-based, community interviewer-involved protocols yields valid data with high compliance. The success of this study was facilitated by exemplary efforts of tribal community-based interviewers and our overall CBPR approach.Lay summaryAuthentic efforts for tribal community partnerships in research are critical to successfully implementing biological assessments with American Indians given legacies of research misconduct and mistrustOur Community-Based Participatory Research with 5 tribes yielded high participant compliance to a home-based salivary cortisol collection protocolLack of compliance to salivary cortisol protocol and medication usage were not consistently associated with observed cortisol indices.

The effect of 30-m repeated sprint exercise on muscle damage indicators, serum insulin-like growth factor-Iand cortisol

Study aim: The purpose of this study was to examine the effects of arepeated sprint exercise protocol on muscle damage indicators, serum IGF-Iand cortisol levels.

Material and methods: Nine trained male subjects (age 23.3 ± 3.6 years) completed arepeated sprint protocol consisting of two sets of 10 × 30-m maximal sprints with 30 s of active recovery between sprints and 5 min of passive recovery between sets. The isometric strength and flexibility were measured before, immediately after and 24 hours after exercise. 30-m maximal sprint time was measured before and 24 hours after exercise. Blood samples were taken before, immediately after and 24 hours after exercise.

Results: Isometric strength and flexibility were significantly decreased after exercise and 24 hours after exercise (p < 0.05). 30-m sprint time was significantly increased 24 hours after exercise (p < 0.05). Asignificant increase in serum lactate dehydrogenase, IGF-Iand cortisol were found after exercise (p < 0.05). Serum creatine kinase increased significantly immediately after and 24 hours after exercise compared to pre-exercise values (p < 0.05).

Conclusion: Our data show that due to increased serum IGF-Ilevel, repeated sprint exercise may have anabolic effects as well as traumatic effects on the muscles.

Psychosocial Stress Reactivity as Predictor of Operative Outcome in Lumbar Disc Surgery

BACKGROUND

A large proportion of the population suffers from chronic back pain. For optimal treatment, the question arises which patients would benefit from conservative therapy and for whom lumbar disc surgery is most appropriate. It seems reasonable to analyze the impact of paraclinical parameters on the operation outcome to identify patients who would benefit less from surgery or need special pre-/postoperative medical care.

MATERIALS AND METHODS

From March 2012 to July 2014, 32 patients were treated via microscopically supported interlaminar fenestration and discectomy at the Department of Neurosurgery, University Hospital Carl Gustav Carus Dresden. One day before the operation, a cortisol survey was made during the stress response of the Trier Social Stress Test. At the same time, a survey of relevant questionnaires was conducted by which the postoperative symptom experience was made operational and comparable with the evaluation of the same information thirty days afterwards.

RESULTS

It could be shown that there is a connection between cortisol reactivity and the pain burden following operations. Patients with a greater cortisol reaction under stress exposition partially experienced more intense postoperative pain than the patients with a lower cortisol reaction. However, this relationship could only be explained by single significant results, whereas further calculations could not produce any significance.

CONCLUSIONS

Cortisol reactivity seems to be associated with pain development. The inconsistent findings in empiricism as well as in this investigation are indicative of a complex association of postoperative pain and cortisol reactivity, which needs to be examined further.

Exercise Reduces Salivary Morning Cortisol Levels in Patients with Depression

Purpose of the Study

Cortisol hypersecretion plays a role in depression pathophysiology. Internet-based cognitive behavioural therapy (ICBT) and physical exercise (PE) are new treatment alternatives for depression, and their long-lasting effect on cortisol is unknown. We investigated cortisol level changes after 12 weeks of ICBT, PE or treatment as usual (TAU).

Procedures

The present pre-post repeated measure study analysed data derived from a randomised controlled trial evaluating the effects of 12 weeks' interventions of ICBT, PE and TAU in depressed primary care patients (Sweden 2011-2013) and aimed at prospectively evaluating the within-group effects of ICBT, PE and TAU on diurnal salivary cortisol levels in a small representative subsample (n = 56, 38 and 27, respectively).

Results

We found a marked flattening of the diurnal cortisol slope (p = 0.004) and a reduced cortisol level at awakening (p = 0.017) after 12 weeks of PE treatment. No apparent effects of ICBT or TAU interventions were seen on diurnal cortisol levels.

Conclusions and Message

PE reduced the rate of cortisol level decline across the day in depressed adults. ICBT and TAU treatments had no detectable effects on diurnal cortisol levels. Larger samples are required for the detection and comparison of smaller effects of PE, ICBT and TAU on diurnal cortisol levels.

Influence of Resistance Exercise on Appetite and Affect Following Pre-Sleep Feeding

To determine changes in appetite, affect and cortisol in response to an acute bout of resistance exercise (RE) the morning after consuming whey (WP) and casein (CP) protein and a non-caloric placebo (PLA) consumed pre-sleep, 14 active men (n = 5) and women (n = 9) consumed a single dose of 24 g WP, 48 g WP, 24 g CP, 48 g CP, or PLA 30 min pre-sleep. Prior to and immediately after RE, appetite, affect and cortisol were assessed. Significant time effects were observed for Energetic Arousal and Tense Arousal (p = 0.017) and Feeling Scale and Felt Arousal Scale (p < 0.001). Appetite did not change over time or condition. Cortisol levels increased after RE (p = 0.007). Pre-RE, Tense Arousal was correlated with hunger (r = 0.25, p = 0.047) and desire to eat (r = 0.35, p = 0.005). Post-RE, cortisol was found to be significantly related to Feeling Scale (r = 0.32, p = 0.018), Felt Arousal Scale (r = 0.33, p = 0.015) and Energetic Arousal (r = 0.32, p = 0.018). Varying doses of WP and CP pre-sleep did not have an effect on morning appetite and cortisol, but cortisol was found to be related to affect and appetite.

Poorer positive affect in response to self-paced exercise among the obese

We aimed to investigate the association between body mass index (BMI) and affective response, ratings of perceived exertion (RPE), and physiological responses during self-paced exercise. Sixty-six women were divided into three groups accordingly with the BMI: obese (n = 22: 33.5 ± 8.5 yr; 34.9 ± 4.1 kg∙m^-2), overweight (n = 22: 34.8 ± 8.6 yr; 26.4 ± 1.3 kg∙m^-2), and normal-weight (n = 22: 30.8 ± 9.3 yr; 22.0 ± 1.6 kg∙m^-2). They underwent a graded exercise test and a 20-min self-paced walking session on a treadmill. Affective responses, RPE, heart rate (HR), and oxygen uptake (VO₂) were recorded every 5 min. The women with obesity experienced the lowest affective rates (p < .001), despite similar RPE, HR, and VO₂ to the other normal weight and overweight groups. In addition, a multiple regression model indicated that BMI was a significant predictor of affective responses (p < .001). In conclusion, the results of the present study suggest that obesity is associated with poorer affective responses to exercise even at self-paced intensity, with the same physiological responses and perceived exertion. Therefore, techniques that aim directly to increase pleasure and/or reduce attentional focus and perception of effort in this population are required, such as affect-regulated prescription, shorter bouts of self-paced exercise throughout the day, distraction away from internal cues (e.g. music, group exercise), etc.

Affect and cortisol mechanisms through which acute exercise attenuates cigarette cravings during a temporary quit attempt

INTRODUCTION

A number of mechanisms have been proposed to explain how exercise attenuates cravings among temporarily abstinent smokers; however, research has presented mixed findings. The aim of this study was to further investigate the mechanistic role of positive and negative affect and cortisol in the exercise-craving reduction relationship.

METHODS

Adult smokers (N=110, male=56, M age=33.1, M cigarettes/day=15.4) provided baseline affective and cortisol data (T1). After an 18-h period of abstinence, participants were randomized to a passive sitting (PSG) or moderate exercise group (MEG; 40-68% of heart rate reserve) for 10min. Affect and cortisol data were also collected immediately before (T2) and after (T3) the condition.

RESULTS

The smoking abstinence manipulation increased cravings (p<0.001, eta=0.40) and negative affect (p<0.001, eta=0.17), as well as decreased positive affect (p<0.001, eta=0.08) and cortisol (trending, p=0.07, η2=0.04). As expected, a significant reduction in cravings from T2 to T3 was found for MEG but not PSG (p<0.001, eta=0.25). Mediation was tested using Sobel and bootstrapping tests with residual change scores of mediators and cravings. Findings showed that both positive and negative affect, but not cortisol, mediated the relationship between exercise and cravings.

CONCLUSIONS

Understanding the mechanisms by which exercise induces craving reductions will better allow researchers and healthcare professionals to infer causality and implement interventions guided by the processes that yield such desirable outcomes.

Impact of physical fitness on salivary stress markers in sedentary to low-active young to middle-aged men

INTRODUCTION

Salivary cortisol (sCort) and alpha-amylase (sAA) are popular measurement tools for investigating hypothalamic-pituitary-adrenal and autonomic functioning, respectively. Despite their widespread use, only little is known about whether lifestyle factors such as regular exercise and physical fitness impact these two salivary stress markers. The lack of an objectively assessed fitness status is a major drawback of nearly all previous studies in this area. Our main objective was therefore to examine the impact of fitness status on sCort and sAA responses to a validated stressor.

METHOD

Sedentary to low-active men (N=115, 45.7±10.1 years, 26.7±3.4kg/m(2)) were exposed to the Trier Social Stress Test for Groups and provided saliva samples before and repeatedly after the stressor. An ergometer lactate exercise test provided information on physical fitness, that is, power achieved at the individual anaerobic threshold relative to body weight. From age-specific percentiles, a 2- (n=65 low fitness, n=50 high fitness) and a 3-group (n=37 low fitness, n=49 moderate fitness, n=29 high fitness) solution were calculated to elucidate the impact of different fitness levels.

RESULTS

Prior to stress testing, sCort and sAA levels were similar in all groups. While both markers increased significantly due to stress exposure, fitness effects appeared rather small. When applying the 3-group solution, we observed attenuated sCort slopes in high- and moderate-fit men. Although sAA response slopes were pronounced in high-fit men, they failed to reach statistical significance. Mean stress reactivity (area under the curve with respect to ground, baseline, and response maximum) did not differ between groups and no association with fitness level was found.

DISCUSSION

Our findings suggest only a weak effect of objectively assessed physical fitness on biological stress responses with attenuated hypothalamic-pituitary-adrenal but (non-significantly) higher autonomic responses in fitter men. Physical fitness is a factor that should not be neglected in future studies employing salivary stress markers, especially in studies interested in acute stress responses.

Effects of leisure activities at home on perceived care burden and the endocrine system of caregivers of dementia patients: a randomized controlled study

BACKGROUND

Psychological stress associated with caregiving is thought to underlie the high incidence of hypertension, ischemic heart disease, and mortality, as well as reduced immune function, among caregivers of dementia patients. Here, we examined the effects of periodic leisure activities performed by caregivers of dementia patients with care recipients at home on perceived care burden and levels of stress hormones.

METHODS

Participants were 42 caregivers aged ≥ 65 years of patients diagnosed with Alzheimer's dementia. They were randomly assigned to intervention and non-intervention groups. The intervention group underwent a leisure activity program (30 min/3 times/week for 24 weeks) with the care recipient, and the control group underwent normal care activities.

RESULTS

The Zarit Burden Interview (ZBI) score, a subjective indicator of care burden, significantly decreased after intervention in the intervention group (p < 0.05), whereas no difference was observed in the control group. No significant changes were observed in adrenaline, noradrenaline, dopamine, and cortisol levels in both groups.

CONCLUSIONS

The lack of changes in stress hormone levels despite a decrease in subjective care burden in the intervention group might be explained by the effects of the chosen leisure activity on the neuroendocrine system. Our findings suggest that periodic leisure activities can reduce perceived care burden among caregivers of dementia patients. However, in order to evaluate accurately the effects of leisure activities of the present study, long-term follow-up of both caregivers and care recipients is necessary. The Nagoya University Department of Medicine Ethics Committee Clinical Trials Registry Number is 1290.

Motivational State and Personality in Relation to Emotion, Stress, and HRV Responses to Aerobic Exercise

Abstract. This study examined emotion, stress, and performance during aerobic exercise performed in the telic and paratelic states, in relation to telic and paratelic dominance. The study tested the misfit effect and is the first to examine heart rate variability (HRV) responses to exercise in relation to both personality and motivational state. Based on their Paratelic Dominance Scale scores, participants identified as telic dominant (TD) and paratelic dominant (PD) completed ramp tests following telic and paratelic state manipulations (repeated measures). In each condition, participants watched “serious” (telic) or “playful” (paratelic) videos for 10 min, then performed a ramp test on a cycle ergometer while continuing to watch the videos throughout the entire protocol. Motivational state (telic/paratelic), HRV, emotion, and stress levels were measured at baseline, pre, post, and 15 min post-ramp test. Time to exhaustion was measured as an index of performance. Limited support was obtained for the misfit effect as interactions between state and dominance were not revealed for any of the variables with the exception of low frequent (LF) and the low frequent/high frequent ratio (LF/HF % normalized), which can be interpreted as indicating that both groups were more relaxed in their preferred state condition. Regardless, findings offer useful insight into methodological considerations for similar studies, such as consideration of the moderating effects of exercise characteristics. Our findings also confirm a number of reversal theory ( Apter, 1982 ) proposals including the concept of dominance as an individual difference factor, with varying characteristics of different dominances, based on physiological response variables. We recommend continued research into the misfit effect with larger samples, and designs that accommodate the methodological considerations raised by the present results.

Changes in salivary hormones, immunoglobulin A, and C-reactive protein in response to ultra-endurance exercises

The aim of the study was to determine the influence of the exercise duration on the changes in salivary stress markers in response to ultra-endurance exercises. The study was developed in 2 ultra-endurance exercise tests: the Ultra-trail Serra de Tramuntana (UTST), a 104 km ultra-marathon competition (n = 64) and the 25 km Cabrera Open Water Race (COWR) (n = 43). Participants in the COWR completed the 25 km at a constant pace of 3 km/h (3K group) or 2.5 km /h (2.5K group). Saliva samples were taken before and after the exercises. Salivary flow rate as well as cortisol, testosterone, C-reactive protein (CRP), and immunoglobulin A (IgA) levels were measured. Salivary flow rate decreased after the UTST but increased after the COWR. The UTST induced significant increases in cortisol and CRP levels and decreases in testosterone and IgA levels. Furthermore, a negative correlation was found between the time the athletes took to complete the exercise and the changes in salivary cortisol. After the COWR, higher increases in salivary cortisol levels were observed in the 3K group than in the 2.5K group. A significant effect of exercise decreasing testosterone and IgA levels was observed in both groups. No changes in the CRP levels were observed during the COWR. In conclusion, shorter times to complete the ultra-endurance exercise were associated with higher increases in cortisol. However, no relationships were found between the time to complete the exercises and the changes in testosterone, CRP, and IgA levels.

Salivary and plasma cortisol and testosterone responses to interval and tempo runs and a bodyweight-only circuit session in endurance-trained men

The aim of this study was to examine the acute response to plasma and salivary cortisol and testosterone to three training protocols. Ten trained endurance athletes participated in three experimental trials, such as interval training (INT), tempo run (TEMP) and bodyweight-only circuit training (CIR), on separate days. Blood and saliva samples were collected pre- and 0, 15, 30 and 60 min post-exercise. Peak post-exercise salivary cortisol was higher than pre-exercise in all trials (P < 0.01). After INT, salivary cortisol remained elevated above pre-exercise than 60 min post-exercise. Salivary testosterone also increased post-exercise in all trials (P < 0.05). Plasma and salivary cortisol were correlated between individuals (r = 0.81, 0.73-0.88) and within individuals (r = 0.81, 0.73-0.87) (P < 0.01). Plasma and salivary testosterone was also correlated between (r = 0.57, 0.43-0.69) and within individuals (r = 0.60, 0.45-0.72), (P < 0.01). Peak cortisol and testosterone levels occurred simultaneously in plasma and saliva, but timing of post-exercise hormone peaks differed between trials and individuals. Further investigation is required to identify the mechanisms eliciting an increase in hormones in response to CIR. Furthermore, saliva is a valid alternative sampling technique for measurement of cortisol, although the complex, individual and situation dependent nature of the hormone response to acute exercise should be considered.

Effects of current physical activity on affective response to exercise: physical and social-cognitive mechanisms

Affective responses during exercise are often important determinants of exercise initiation and maintenance. Current physical activity may be one individual difference that is associated with the degree to which individuals have positive (or negative) affective experiences during exercise. The objective of this study was to explore physical and cognitive explanations of the relationship between current activity status (more versus less active) and affective response during a 30-minute bout of moderate-intensity exercise. Participants reported their current level of physical activity, exercise self-efficacy and affect during a 30-minute bout of moderate-intensity exercise. More active individuals experienced higher levels of positive affect and tranquillity and lower levels of negative affect and fatigue during exercise. Multivariate models for each affective state indicated separate processes through which physical activity may be associated with changes in affect during exercise. These models indicate that affect experienced during physical activity is related to the current activity level and these relationships can be partially explained by the physical and cognitive factors explored in this study. Recommendations for future research to elucidate whether positive affective response to physical activity improves as a function of becoming more active over time are discussed.

Efeitos agudos do treinamento concorrente sobre os níveis séricos de leptina e cortisol em adultos jovens sobrepesados

OBJETIVO: Este estudo teve como objetivo analisar os efeitos imediatos do treinamento concorrente sobre a leptina e os níveis de cortisol em adultos jovens com sobrepeso. MÉTODOS: Este estudo utilizou uma metodologia quase-experimental. Foram 20 indivíduos voluntários de ambos os sexos, divididos em um grupo sobrepesado treinamento (GST n = 10) e um grupo sobrepesado controle (n = 10). A coleta de sangue foi realizada com os indivíduos em repouso após jejum de 12 horas. Os níveis de leptina e cortisol foram analisados por radioimunoensaio e ensaio por quimioluminescência chimiluminescence antes e imediatamente após o treinamento. ANOVA two way foi utilizada para análise estatística com nível de significância de p < 0,05. RESULTADOS: Na análise da leptina sérica, observou-se diferença significativa intergrupos (GST x GSC) nos momentos pré-intervenção (p = 0,02) e pós-intervenção (p = 0,01). Na análise intragrupos, não foram observadas alterações significativas. E na análise do cortisol sérico intergrupos (GST x GSC), foi observada uma diferença significativa nos momentos pré-intervenção (p = 0,01) e pós-intervenção (p = 0,01), porém, na análise intragrupos, não houve alterações significativas. CONCLUSÃO: Uma única sessão de treinamento concorrente não é suficiente para promover alterações agudas nos níveis de leptina e cortisol dos jovens adultos sobrepesados voluntários deste estudo.

Complex interplay between determinants of pacing and performance during 20-km cycle time trials

PURPOSE

This study examined the determinants of pacing strategy and performance during self-paced maximal exercise.

METHODS

Eight well-trained cyclists completed two 20-km time trials. Power output, rating of perceived exertion (RPE), positive and negative affect, and iEMG activity of the active musculature were recorded every 0.5 km, confidence in achieving preexercise goals was assessed every 5 km, and blood lactate and pH were measured postexercise. Differences in all parameters were assessed between fastest (FAST) and slowest (SLOW) trials performed.

RESULTS

Mean power output was significantly higher during the initial 90% of FAST, but not the final 10%, and blood lactate concentration was significantly higher and pH significantly lower following FAST. Mean iEMG activity was significantly higher throughout SLOW. Rating of perceived exertion was similar throughout both trials, but participants had significantly more positive affect and less negative affect throughout FAST. Participants grew less confident in their ability to achieve their goals throughout SLOW.

CONCLUSIONS

The results suggest that affect may be the primary psychological regulator of pacing strategy and that higher levels of positivity and lower levels of negativity may have been associated with a more aggressive strategy during FAST. Although the exact mechanisms through which affect acts to influence performance are unclear, it may determine the degree of physiological disruption that can be tolerated, or be reflective of peripheral physiological status in relation to the still to be completed exercise task.

Concentrations of salivary testosterone, cortisol, and immunoglobulin A after supra-maximal exercise in female adolescents

The aim of this study was to examine the effect of supra-maximal exercise on circulating concentrations of salivary testosterone, salivary cortisol, and salivary immunoglobulin A in female adolescents. Nineteen apparently healthy females aged 15-16 years participated in this study. All participants completed 668 s sprints, interspersed with 30 s recovery intervals on a cycle ergometer. Salivary testosterone, cortisol, and immunoglobulin A samples were taken before and 5 min after exercise. Experimental procedures continued over two mornings, at least 3 h after a light breakfast. Participants refrained from performing any strenuous physical activity for at least 24 h prior to the exercise test. None of the participants were engaged in a structured training programme. The group mean (± s) for peak power output was 562 ± 113.0 W. Female adolescents recruited for this study showed no changes in salivary testosterone, cortisol or immunoglobulin A following repeated bouts of supra-maximal cycling (P > 0.05). To date, there has been a paucity of information concerning adolescents' hormonal and mucosal immune function responses to supra-maximal exercise. Our data provide further guidance with regard to physical activities and sports prescription for female adolescents. Further research, on a larger sample of females, is required to elucidate the physiological significance of these findings.

Neurobiological alterations induced by exercise and their impact on depressive disorders [corrected]

BACKGROUND

The impact of physical activity on brain metabolic functions has been investigated in different studies and there is growing evidence that exercise can be used as a preventive and rehabilitative intervention in the treatment of depressive disorders. However, the exact neuronal mechanisms underlying the latter phenomenon have not been clearly elucidated. The present article summarises key results derived from studies that focussed on the neurobiological impact of exercise on brain metabolic functions associated with depressive disorders. Since major depressive disorder (MDD) is a life threatening disease it is of great significance to find reliable strategies to prevent or to cure this illness. Therefore, the aim of this paper is to review (1) the physiological relationship between physical activity and depressive disorders and (2) the potential neurobiological alterations induced by exercise that might lead to the relief of mental disorders like depression.

METHODS

We searched electronic databases for literature concerning the relationship between exercise and depression from 1963 until 2009.

RESULTS

The data suggests an association between physical inactivity and higher levels of depressive symptoms. Properly designed studies could show that exercise training can be as effective as antidepressive medications.

CONCLUSION

The exact mechanisms how exercise affects the brain are not fully understood and the literature lacks of well designed studies concerning the effects of exercise training on depressive disorders. But the observed antidepressant actions of exercise are strong enough that it already can be used as an alternative to current medications in the treatment of depressive disorders.

Effect of acute exercise on the levels of salivary cortisol, tumor necrosis factor-alpha and nitric oxide

The aim of the present study was to assess the levels of salivary cortisol, tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) before, during and after acute exercise. Acute exercise was induced using a standard treadmill test with Bruce protocol in ten physically active male participants. Unstimulated saliva was collected before, during and after exercise. The levels of salivary cortisol and TNF-alpha were assessed by enzyme immunoassays. Salivary NO was determined by the Griess reagent. The results showed that both salivary cortisol and TNF-alpha increased and peaked at 14 min during exercise and then decreased. The levels of NO were increased up to 1 h after exercise and subsequently lowered after 24 h. The results of the present study suggest that acute exercise may induce high levels of salivary cortisol, TNF-alpha and NO.

Mental and physical fatigue-related biochemical alterations

OBJECTIVE

To confirm fatigue-related biochemical alterations, we measured various parameters just before and after relaxation and fatigue-inducing mental or physical sessions.

METHODS

Fifty-four healthy volunteers were randomized to perform relaxation and fatigue-inducing mental and physical sessions for 4 h in a double-blind, three-crossover design. Before and after each session, subjects were asked to rate their subjective sensations of fatigue, and blood, saliva, and urine samples were taken.

RESULTS

After the fatigue-inducing mental and physical sessions, subjective scores of fatigue were increased. After the fatigue-inducing mental session, the vanillylmandelic acid level in urine was higher and plasma valine level was lower than after the relaxation session. In contrast, after the fatigue-inducing physical session, serum citric acid, triacylglycerol, free fatty acid, ketone bodies, total carnitine, acylcarnitine, uric acid, creatine kinase, aspartate aminotransferase, lactate dehydrogenase, cortisol, dehydroepiandrosterone, dehydroepiandrosterone sulfate, plasma branched-chain amino acids, transforming growth factor-beta1 and -beta2, white blood cell and neutrophil counts, saliva cortisol and amylase, and urine vanillylmandelic acid levels were higher and serum free carnitine and plasma total amino acids and alanine levels were lower than those after the relaxation session.

CONCLUSION

Some mental or physical fatigue-related biochemical changes were determined. Various biochemical alterations reflecting homeostatic perturbation and its responses might be shown. We believe that our results contribute to clarifying the mechanism of fatigue, developing evaluation methods, and establishing a basis for treatment.

Exercise and circulating cortisol levels: the intensity threshold effect

This study examined the influence of exercise intensity upon the cortisol response of the hypothalamic-pituitary-adrenal (HPA) axis. Specifically, we examined exercise at intensities of 40, 60, and 80% maximal oxygen uptake (VO2max) in an attempt to determine the intensity necessary to provoke an increase in circulating cortisol. Twelve active moderately trained men performed 30 min of exercise at intensities of 40, 60, and 80% of their VO2max, as well as a 30-min resting-control session involving no exercise on separate days. Confounding factors such as time of day--circadian rhythms, prior diet--activity patterns, psychological stress, and levels of exercise training were controlled. Cortisol and ACTH were assessed in blood collected immediately before (pre-) and after (post-) each experimental session. Statistical analysis involved repeated measures analysis of variance and Tukey post-hoc testing. The percent change in cortisol from pre- to post-sampling at each session was: resting-control, 40, 60, and 80% sessions (mean+/-SD) =-6.6+/-3.5%, +5.7+/-11.0%, +39.9+/-11.8%, and +83.1+/-18.5%, respectively. The 60% and 80% intensity magnitude of change was significantly greater than in the other sessions, as well as from one to another. The ACTH responses mirrored those of cortisol, but only the 80% exercise provoked a significant (p<0.05) increase pre- to post-exercise. The calculated changes in plasma volume for the resting-control, 40%, 60%, and 80% sessions were: +2.2+/-3.0%, -9.9+/-5.0%, -15.6+/-3.5%, and -17.2+/-3.3%, respectively. Collectively, the cortisol findings support the view that moderate to high intensity exercise provokes increases in circulating cortisol levels. These increases seem due to a combination of hemoconcentration and HPA axis stimulus (ACTH). In contrast, low intensity exercise (40%) does not result in significant increases in cortisol levels, but, once corrections for plasma volume reduction occurred and circadian factors were examined, low intensity exercise actually resulted in a reduction in circulating cortisol levels.

Motivation, stress, anxiety, and cortisol responses in elite paragliders

In this study metamotivational dominance (measured with the Telic Dominance Scale), precompetition anxiety (evaluated with the CSAI-2), perceived stress (measured with the Perceived Stress Scale), and cortisol responses by 10 paragliding competitors prior to and following a paragliding competition were examined. Saliva was collected for each subject for cortisol analysis on eight occasions: during a resting day (baseline values) and prior to and after competition. Analysis indicated subjects were all paratelic-dominant (characterized by a desire for high arousal, a focus on the present). Scores were high on the Perceived Stress Scale and cognitive nxiety (a telic emotion). Cortisol values showed a significant increase early on the day of the competition and remained elevated all the day, with highest concentrations at the start. Participants' cognitive anxiety and cortisol responses were significantly correlated .79 just before the jump and the direction of the cognitive anxiety was rated as facilitative of performance. These results may suggest that the more frequently the subject is playful in life, the more cortisol they produce when aroused in a less frequent telic state.

Mastery motivational climate: influence on physical play and heart rate in African American toddlers

The purpose of this study was to determine the effectiveness of a planned mastery motivational physical play session on physical activity (i.e., heart rate [HR] and physical play intensity [PAHR > 50]) in toddlers (N = 21), as compared to a nonplanned free play session. Participants wore a monitor to measure HR over two, 30 min play conditions. A multivariate analysis of variance was conducted to evaluate the effect of the play conditions. A significant difference between conditions and physiological measures revealed that the mastery motivational physical play session resulted in higher HR and PAHR > 50 when compared to free play. These findings suggest the mastery motivational session resulted in more vigorous physical play in toddlers than free play.

Effect of zinc supplementation on thyroid hormone function. A case study of two college females

BACKGROUND/AIMS

Zinc is crucial for proper thyroid hormone metabolism; zinc deficiency may result in decreased thyroid hormone levels and resting metabolic rate (RMR). The purpose of this investigation was to assess the effects of zinc supplementation on plasma zinc, serum ferritin, plasma total triiodothyronine (T(3)) and thyroxine (T(4)), serum free T(3) and T(4), and thyroid-stimulating hormone concentrations, and RMR in zinc-deficient, physically active women.

METHODS

Two zinc-deficient female college students (ZD1 and ZD2) were supplemented with 26.4 mg/day of zinc (as zinc gluconate), and the above parameters were analyzed at 0, 2 and 4 months.

RESULTS

Zinc deficiency was clinically corrected in both subjects, while serum ferritin concentration declined to classify both subjects as borderline iron deficient (ZD1 = 15.3 and ZD2 = 15.3 ng/ml at 4 months). At 4 months, total T(3) concentrations increased in ZD1, while all thyroid hormone concentrations increased in ZD2. RMR increased in both subjects by 4 months.

CONCLUSION

Zinc supplementation appeared to be directly responsible for the increase in plasma zinc and decline in serum ferritin concentrations in both subjects. Zinc supplementation appeared to have a favorable effect on thyroid hormone levels, particularly total T(3), and RMR.

Effect of carbohydrate and prolonged exercise on affect and perceived exertion

INTRODUCTION

It has been reported that perceptions of exertion are attenuated during prolonged cycle exercise, following CHO ingestion. However, no studies to date have examined the influence of such feedings on psychological affect during prolonged exercise, even though affect and perceived exertion are different constructs.

PURPOSE

To examine the influence of regular CHO beverage ingestion on affect (pleasure-displeasure) and perceived exertion during prolonged cycle exercise.

METHODS

In a randomized, double-blind, counterbalanced design, nine endurance trained males cycled for 2 h at 70% VO2max on two occasions, separated by 1 wk. On each occasion, they consumed either a water placebo (PLA) or a 6.4% carbohydrate-electrolyte solution (CHO) immediately before they cycled (5 mL x kg(-1) body mass) and every 15 min thereafter (2 mL x kg(-1) body mass). Pleasure-displeasure was assessed before, during, and after the prolonged bout of cycling.

RESULTS

During exercise, reported pleasure initially improved and was subsequently maintained in the CHO trial, in contrast to a decline reported in the PLA trial. Ratings of pleasure-displeasure were more positive during recovery in the CHO trial compared with the PLA trial (P < 0.05) and the only significant increase (P < 0.05) in pleasure occurred 15 min postexercise in the CHO trial only. RPE increased (P < 0.05) over the course of the bout of cycling and was lower (P < 0.05) 75 min into exercise in the CHO trial. Immediately postexercise, plasma glucose concentration was higher in the CHO compared with the PLA trial (P < 0.05). A main effect of trial was found for plasma cortisol concentration, with higher values reported in PLA trial.

CONCLUSION

Results suggest that CHO ingestion enhanced feelings of pleasure during and following prolonged cycling and highlighted the importance of assessing not only "what," but also "how" a person feels.

Effects of physical exercise on depression, neuroendocrine stress hormones and physiological fitness in adolescent females with depressive symptoms

BACKGROUND

Regular physical exercise may improve a variety of physiological and psychological factors in depressive persons. However, there is little experimental evidence to support this assumption for adolescent populations. We conducted a randomized controlled trial to investigate the effect of physical exercise on depressive state, the excretions of stress hormones and physiological fitness variables in adolescent females with depressive symptoms.

METHODS

Forty-nine female volunteers (aged 18-20 years; mean 18.8 +/- 0.7 years) with mild-to-moderate depressive symptoms, as measured by the Centre for Epidemiologic Studies Depression (CES-D) scale, were randomly assigned to either an exercise regimen or usual daily activities for 8 weeks. The subjects were then crossed over to the alternate regimen for an additional 8-week period. The exercise program consisted of five 50-min sessions per week of a group jogging training at a mild intensity. The variables measured were CES-D rating scale, urinary cortisol and epinephrine levels, and cardiorespiratory factors at rest and during exercise endurance test.

RESULTS

After the sessions of exercise the CES-D total depressive score showed a significant decrease, whereas no effect was observed after the period of usual daily activities (ANOVA). Twenty-four hour excretions of cortisol and epinephrine in urine were reduced due to the exercise regimen. The training group had a significantly reduced resting heart rate and increased peak oxygen uptake and lung capacity.

CONCLUSIONS

The findings of this study suggest that a group jogging exercise may be effective in improving depressive state, hormonal response to stress and physiological fitness of adolescent females with depressive symptoms.

Maximal strength and cortisol responses to psyching-up during the squat exercise

We studied the effect of psyching-up on one-repetition maximum (1-RM) performance and salivary cortisol responses during the squat exercise. Ten men (age 21.6+/-1.4 years; mean+/-s) and ten women (age 22.4+/-2.8 years) with weight training experience of 4.5+/-2.0 years participated in this study. One-repetition maximum squats were performed on a Smith machine during each of two different intervention conditions that were counterbalanced and consisted of a free choice psych-up and a cognitive distraction. Saliva samples were obtained at the beginning of each test session and immediately after the final 1-RM attempt. No significant difference in 1-RM was identified between psyching-up (104+/-50 kg) and cognitive distraction (106+/-52 kg). Performing a 1-RM in the squat exercise significantly increased salivary cortisol concentrations during both conditions (P<0.05). There was no significant difference in salivary cortisol responses between conditions. These results suggest that psyching-up does not increase 1-RM performance during the squat exercise in strength-trained individuals.

Motivation, stress, and cortisol responses in skydiving

This study examined metamotivational dominance, metamotivational states, and cortisol responses in skydiving participants. Data were obtained from 23 experienced skydivers 15 min. prior to and following a skydive. Respondents were mainly paratelic-conformist dominant and most occupied the conformist and arousal-seeking states prior to skydiving, assessed respectively, with Apter, et al.'s Motivational Style Profile and Cook, et al.'s measure of metamotivational states. Paratelic-conformist dominance indicates a predisposition towards conformity and a desire to be spontaneous, and the conformist and arousal seeking states reported prior to completing the skydive represent a desire to conform to expected norms but also to seek arousal. There was no significant change in scores for metamotivational state or stress following skydiving. Contrary to expectations, cortisol level prior to skydiving was negatively associated with external stress. These results support the paratelic, but not the negativistic, dominance found in previous samples of risk sport participants (no skydivers). The conformist dominance and pre-dive conformist metamotivational state scores of this sample may be fundamental for adhering to safety regulations imposed on skydivers. To obtain better understanding of this phenomenon, researchers should attempt to measure these variables during, rather than prior to and after, participation in risk sports.

Circadian effects on the acute responses of salivary cortisol and IgA in well trained swimmers

OBJECTIVE

To examine whether time of day significantly affects salivary cortisol and IgA levels before and after submaximal swimming.

METHODS

Fourteen male competitive swimmers (mean (SD) age 18 (3.2) years) volunteered to participate in the study. In a fully randomised, cross over design, each subject performed 5 x 400 m front crawl at 85 (1.2)% of their seasonal best time (277 (16) seconds), with one minute rest between each 400 m, at 0600 and 1800 hours on two separate days. Timed, unstimulated saliva samples were collected before and after exercise. Saliva samples were analysed for cortisol and IgA by radioimmunoassay and single radial immunodiffusion respectively.

RESULTS

Significant time of day effects (am and pm respectively) were observed in IgA concentration (0.396 (0.179) v 0.322 (0.105) mg/ml, p<0.05), IgA secretory rate (0.109 (0.081) v 0.144 (0.083) mg/min, p<0.01), and saliva flow rate (0.31 (0.23) v 0.46 (0.22) ml/min, p<0.001) before exercise (all values mean (SD)). Differences in cortisol levels before exercise (1.09 (0.56) v 0.67 (0.94) microg/dl) approached significance (p = 0.059). The exercise protocol did not significantly affect IgA concentration and secretory rate (p>0.05) but, in comparison with values before exercise, caused significant alterations in cortisol (p<0.01) and saliva flow rate (p<0.01). There was no significant interaction effect of time of day by exercise on any salivary variables measured (p>0.05). However, most of the values of the salivary variables before exercise were significantly inversely related to their exercise induced response (p<0.05).

CONCLUSION

These results suggest a significant circadian variation in the variables measured before exercise, without showing a significant effect on their acute responses to exercise.

Influence of fitness on the integrated neuroendocrine response to aerobic exercise until exhaustion

A group of trained and sedentary men performed an incremental graded exercise-test to exhaustion in order to assess the organic response of the two main stress-activated systems: the sympathetic nervous system with its endocrine component (the adrenal medulla), and the hypothalamic-pituitary-adrenal (HPA) axis. Maximal plasma concentrations of ACTH, cortisol and endogenous opioids (beta-endorphins) were obtained at the end of the exercise-test in the trained group. Thus ACTH increased from basal value of 21.25 +/- 2.5 pg/ml to 88.78 +/- 11.8 pg/ml at the end of the exercise (p<0.01); cortisol, from 16.56 microg/dl +/- 4.94 microg/dl to 23.80 +/- 4.57 microg/dl in min 15 of the recovery period (p<0.001); and beta-endorphin from 21.80 +/- 8.33 pmol/ml to 64.36 +/- 9.8 pmol/ml in min 3 of the recovery period (p<0.05). Catecholamine levels were increased from initial values at the end of the effort test in both control and trained groups. Control subjects exhibited a higher responsiveness compared to trained and showed superior intrinsic stimulation of the sympathetic nervous system. These results reveal a different response according to fitness in a physical stress situation.

Reactivity and recovery from different types of work measured by catecholamines and cortisol: a systematic literature overview

OBJECTIVES

To review occupational health, laboratory, and sports literature on neuroendocrine reactivity and recovery from mental, combined mental and physical, or physical tasks.

METHODS

A systematic literature search was performed in eight databases. Studies with catecholamines or cortisol as effect variables measured in blood, urine, or saliva were included.

RESULTS

After application of inclusion and exclusion criteria, 77 studies from the initial 559 identified were taken into account. In occupational settings it was found that relatively few studies were conclusive about recovery, which formed a contrast with sports research. For reactivity and recovery up to 1 hour after performing the task, half of the studies considered physical tasks and more than two thirds showed incomplete recovery compared with baseline excretion of catecholamines and cortisol. Recovery extending to 3 days after the task was performed was often incomplete for cortisol after combined mentally and physically demanding tasks, and less often after solely mental or physical tasks. This type of recovery was more often incomplete for adrenaline (epinephrine) than for noradrenaline (norepinephrine), which was the case after mental as well as combined mental and physical tasks.

CONCLUSIONS

The results from laboratory and sports research may be transferable to some occupations, but more research is needed on the course of recovery relative to health effects in occupational settings.