Hypothalamic dysfunction in overtrained athletes

Assessing the risk of low energy availability, bone mineral density and psychological strain in endurance athletes

BACKGROUND

Adequate energy intake is crucial for athletic performance and recovery. However, many endurance athletes experience Low Energy Availability (LEA), which, if prolonged, can detrimentally impact both health and performance.

METHODS

A total of 55 endurance athletes (23 females; 45  ±  13 years, 1.64  ±  0.06 m, 64.4  ±  11.4 kg and 32 males; 44  ±  13 years, 1.76  ±  0.18 m, 78.8  ±  9.2 kg) underwent physical assessments and completed questionnaires on dietary habits, training loads, and psychological stress. Dual-Energy X-ray Absorptiometry (DEXA) scans measured bone mineral density (BMD) in the lumbar L1-L4 spine, and body composition. Risk of LEA burnout, and psychological strain were assessed using sport-specific questionnaires.

RESULTS

Seventy-seven percent of female athletes were identified as at risk of LEA by the LEAF-Q. These females had higher body weight and fat percentage than those at low risk of LEA. Male athletes had a higher prevalence of low lumbar BMD (31%) compared to females, associated with older age, and longer training histories. Although only 9% of female athletes had low-BMD, those affected had a history of amenorrhea and were identified as at risk of LEA by the LEAF-Q.

CONCLUSION

A high proportion of endurance athletes had low-BMD and were at risk of LEA. This underscores the need for targeted nutritional strategies to mitigate the risks associated with LEA and promote overall athlete well-being.

Interactive effect of sleep duration, lifestyle factors and comorbidity on depressive symptoms: Insights from the China health and retirement longitudinal study

BACKGROUND

As population aging intensifies, depression emerges as a major global public health issue, especially affecting middle-aged and elderly individuals. While studies have investigated factors like sleep duration, physical activity, smoking, drinking habits, and comorbidity, the complex interplay and cumulative effect of these factors on the risk of depressive symptoms remain not fully understood.

METHODS

This research utilizes data from the China Health and Retirement Longitudinal Study (CHARLS), encompassing observations from 2015 to 2020. The subjects included 8234 middle-aged and elderly individuals, accounting for a total of 22,570 observations. Lifestyle factors were represented by physical activity, smoking, and drinking habits, with the volume of moderate-to-vigorous physical activity (MVPA) quantified by quoting metabolic equivalents (MET). Multivariate logistic regression models were conducted for baseline analysis, and mixed-effects logistic regression models with random participant intercepts were constructed for the longitudinal analysis of the cohort. Moreover, interaction terms between these factors were included to assess their combined impact on the risk of depressive symptoms.

RESULTS

Longitudinal analysis revealed a notable correlation between short sleep duration (<7 h) and an elevated risk of depressive symptoms, evidenced by an adjusted odds ratio (OR) of 3.13 (95 % CI: 2.73-3.74). Conversely, long sleep duration (>9 h) was not associated with a marked change in risk of depressive symptoms (OR = 1.11, 95 % CI: 0.78-1.59, p = 0.59). High levels of physical activity (192-336 MET-h/week) were significantly linked to an elevated risk of depressive symptoms (OR = 1.70, 95 % CI: 1.19-2.42). Discontinuing smoking was significantly correlated with a lower risk of depressive symptoms (OR = 0.68, 95 % CI: 0.52-0.90). Subjects with two or more concurrent conditions exhibited a substantially higher risk of depressive symptoms (OR = 3.19, 95 % CI: 3.13-3.25). Investigating the combined influence of sleep duration, lifestyle elements, and concurrent conditions revealed that enhanced physical activity levels significantly decreased risk of depressive symptoms in participants with short sleep duration, adjusting the OR from 3.16 to 0.83 (95 % CI, 0.53-1.30). Among participants with short sleep duration, smoking and alcohol consumption patterns were linked to a decreased risk of depressive symptoms, although these associations lacked statistical significance. Relative to subjects without concurrent conditions, those harboring two or more such conditions faced a significantly heightened risk of depressive symptoms in the context of short sleep duration (OR = 3.00, 95 % CI: 2.24-4.03), a risk not observed in subjects with extended sleep duration. Moderate napping (0.5-1 h) among participants with short sleep duration was found to significantly mitigate risk of depressive symptoms (OR = 0.64, 95 % CI: 0.44-0.95), whereas in subjects with prolonged sleep duration, extended napping did not significantly alter risk of depressive symptoms.

LIMITATIONS

The results, derived from a middle-aged and elderly Chinese population, may not be generalizable to other demographic groups or cultural contexts.

CONCLUSION

This study shows that short sleep duration, unhealthy lifestyle factors, and comorbidities significantly increase the risk of depressive symptoms in middle-aged and elderly individuals. Moderate physical activity, smoking cessation, moderate drinking, and appropriate napping can mitigate this risk, especially for those with short sleep duration. These findings highlight the need to address sleep quality, promote healthy habits, and manage comorbidities in mental health interventions for this population.

Physiology and Pathophysiology of Marathon Running: A narrative Review

BACKGROUND

Marathon training and running have many beneficial effects on human health and physical fitness; however, they also pose risks. To date, no comprehensive review regarding both the benefits and risks of marathon running on different organ systems has been published.

MAIN BODY

The aim of this review was to provide a comprehensive review of the benefits and risks of marathon training and racing on different organ systems. A predefined search strategy including keywords (e.g., marathon, cardiovascular system, etc.) and free text search was used. Articles covering running regardless of sex, age, performance level, and event type (e.g., road races, mountain marathons) were considered, whereas articles examining only cycling, triathlon, stress-tests or other sports were excluded. In total, we found 1021 articles in PubMed, Scopus, and Google Scholar, of which 329 studies were included in this review. Overall, marathon training offers several benefits for different organ systems and reduces all-cause mortality. As such, it improves cardiovascular risk factors, leads to favorable cardiac adaptations, enhances lung function, and improves quality of life in chronic kidney disease patients. It also enhances gastrointestinal mobility and reduces the risk of specific tumors such as colorectal cancer and hepatocellular carcinoma. Marathon training enhances bone health and skeletal muscle metabolism. It further positively affects hematopoiesis and cytotoxic abilities of natural killer cells, and may act neuroprotective on a long-term basis. After a marathon, changes in biomarkers suggesting pathological events in certain organ systems such as cardiovascular, renal, gastrointestinal, liver, hematological, immune, musculoskeletal, central nervous, and endocrine systems can often be observed. Mostly, these changes are limited to 1-3 days post-race and usually normalize within a week. Moreover, marathon running poses the risk of serious adverse events such as sudden cardiac death or acute liver failure. Concerning lung function, a decrease after a marathon race was observed. Acute kidney injury, as well as electrolyte imbalances, are relatively common amongst marathon finishers. Many runners complain of gastrointestinal symptoms during or after long-distance running. Many runners suffer from running-related musculoskeletal injuries often impairing performance. A marathon is often accompanied by an acute inflammatory response with transient immunosuppression, making runners susceptible to infections. Also, hormonal alterations such as increased cortisol levels or decreased testosterone levels immediately after a race are observed. Disturbances in sleep patterns are commonly found in marathon runners leading up to or directly after the race.

CONCLUSION

All in all, marathon training is generally safe for human health and individual organ systems. Considering the high popularity of marathon running, these findings supply athletes, coaches, sports scientists, and sports medicine practitioners with practical applications. Further large-scale studies examining long-term effects on the cardiovascular, renal, and other system are needed.

Changes in the hormonal and inflammatory profile of young sprint- and endurance-trained athletes following a sports camp: a nonrandomized pretest-posttest study

BACKGROUND

The study aimed to compare catecholamine, cortisol, and immune response in sprint- and endurance-trained athletes under the same training, aiming to observe if their sport specialization affects these markers during a 9-day training camp.

METHODS

The study involved twenty-four young male (age 15.7 ± 1.6 years) and female (age 15.1 ± 1,3 years) athletes specializing in sprint and endurance athletics discipline. Blood samples for all measured parameters were taken at rested baseline, on the 4th day, and on the 9th day of training.

RESULTS

In both investigated groups a nonsignificant decrease in catecholamine levels was observed after 4 days of training, which remained stable throughout the camp. The cortisol level increased significantly in both athlete groups (sprint: T-0 vs. T-1 p = 0.0491; T-0 vs. T-3 p = 0.0001; endurance: T-0 vs. T-1 p = 0.0159; T-0 vs. T-3 p = 0.0005). The level of hs-CRP (sprint: T-0 vs. T-1 p = 0.0005; T-0 vs. T-3 p = 0.0001; endurance: T-0 vs. T-3 p = 0.0005), and myoglobin (sprint: T-0 vs. T-1 p = 0.0014; T-0 vs. T-3 p = 0.0001; endurance: T-0 vs. T-3 p = 0.0005) have increased and of hs-CRP and myoglobin level was significantly higher in sprint compared to endurance athletes (p < 0.05). The leukocyte level significantly decreased until the end of camp in both groups (sprint: T-0 vs. T-1 p = 0.0178; T-0 vs. T-3 p = 0.0175; endurance: T-0 vs. T-1 p = 0.0362; T-0 vs. T-3 p = 0.0362).

CONCLUSIONS

The applied training loads had a strong physiological impact leading to changes in stress hormones and immune responses depending on athletes` sport specialization. Training loads caused stronger responses in sprint athletes. However, both groups showed signs of severe fatigue development.

TRIAL REGISTRY

ClinicalTrials.gov ID: NCT06150105, retrospectively registered on 29.11.2023.

Influence of energy availability on metabolic hormonal profiles in east African female and male distance runners

BACKGROUND

Energy availability (EA) and relative energy deficiency in sport (RED-S) are understudied in East African endurance athletes, both females (F) and males (M). This study assessed the metabolic hormonal profiles of such athletes relative to their EA status.

METHODS

Forty athletes (F=16, M=24) had their EA status, training, maximal oxygen uptake, and resting blood samples assessed using standard research practices. Subjects were stratified into two groups, high EA (HiEA) and low EA (LoEA) based on combined median value.

RESULTS

Cortisol (P=0.034) and insulin (P=0.044) were significantly elevated in the LoEA group, while growth hormone (P=0.045) was significantly suppressed; and, prolactin (P=0.078) trended towards suppression, respectively compared to the HiEA group. All other hormonal comparison were non-significant.

CONCLUSIONS

Metabolic hormonal profiles of female and male African distance runners are affected by their EA status. Aspects of these alterations agree in part with published findings based upon White populations, although some differences exist and need further investigation.

The Potential Role of Nutrition in Overtraining Syndrome: A Narrative Review

Competition between athletes and an increase in sporting knowledge have greatly influenced training methods while increasing the number of them more and more. As a result, the number of athletes who have increased the number and intensity of their workouts while decreasing recovery times is rising. Positive overtraining could be considered a natural and fundamental process when the result is adaptation and improved performance; however, in the absence of adequate recovery, negative overtraining could occur, causing fatigue, maladaptation, and inertia. One of the earliest forms of fatigue is overreaching. It is considered to be an accumulation of training that leads to reduced sports performance, requiring days or weeks to recover. Overreaching, if followed by adequate recovery, can lead to an increase in athletic performance. Nonetheless, if overreaching becomes extreme, combined with additional stressors, it could lead to overtraining syndrome (OTS). OTS, caused by systemic inflammation, leads to central nervous system (CNS) effects, including depressed mood, further inflammation, central fatigue, and ultimately neurohormonal changes. There are therefore not only physiological, biochemical, and immunological but also psychological symptoms or markers that must be considered, independently or together, being intrinsically linked with overtraining, to fully understand OTS. However, to date, there are very few published studies that have analyzed how nutrition in its specific food aspects, if compromised during OTS, can be both etiology and consequence of the syndrome. To date, OTS has not yet been fully studied, and the topic needs further research. The purpose of this narrative review is therefore to study how a correct diet and nutrition can influence OTS in all its aspects, from prevention to treatment.

Beneficial Performance Effects of Training Load Intensification Can Be Abolished by Functional Overreaching: Lessons From a Water Polo Study in Female Athletes

ABSTRACT

Brisola, GMP, Dutra, YM, Murias, JM, and Zagatto, AM. Beneficial performance effects of training load intensification can be abolished by functional overreaching: Lessons from a water polo study in female athletes. J Strength Cond Res XX(X): 000-000, 2022-The purpose of this study was to compare the outcomes from 2 weeks of training load intensification strategy in female water polo players diagnosed with functional overreaching (F-OR) with no F-OR players (acute fatigue) on the performance outcomes and hormonal, immunological, and cardiac autonomic nervous system responses. Twenty-two female water polo players were allocated into control and intensification group during 7 weeks. The swimming performance, biochemical parameters, heart rate variability, profile of mood states, and upper respiratory tract infection symptoms were assessed twice before and twice after 2 weeks of intensification period. F-OR showed a worsening in total time of the repeated sprint ability (RSA) test compared with the control group and the acute fatigue group after intensification (p ≤ 0.035). Furthermore, after the tapering period, the F-OR group maintained worse total time of the RSA test than the acute fatigue group (p = 0.029). In addition, the acute fatigue group showed improvement in total time of the RSA test after intensification compared with the control group (p < 0.001). No significant interactions were found for the other parameters. Therefore, periods of intensification without the F-OR development can promote higher gains in the total time of the RSA test after intensification and tapering period.

Diagnosing Overtraining Syndrome: A Scoping Review

CONTEXT

Overtraining syndrome (OTS) is a condition characterized by a long-term performance decrement, which occurs after a persisting imbalance between training-related and nontraining-related load and recovery. Because of the lack of a gold standard diagnostic test, OTS remains a diagnosis of exclusion.

OBJECTIVE

To systematically review and map biomarkers and tools reported in the literature as potentially diagnostic for OTS.

DATA SOURCES

PubMed, Web of Science, and SPORTDiscus were searched from database inception to February 4, 2021, and results screened for eligibility. Backward and forward citation tracking on eligible records were used to complement results of database searching.

STUDY SELECTION

Studies including athletes with a likely OTS diagnosis, as defined by the European College of Sport Science and the American College of Sports Medicine, and reporting at least 1 biomarker or tool potentially diagnostic for OTS were deemed eligible.

STUDY DESIGN

Scoping review following the guidelines of the Joanna Briggs Institute and PRISMA Extension for Scoping Reviews (PRISMA-ScR).

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Athletes' population, criteria used to diagnose OTS, potentially diagnostic biomarkers and tools, as well as miscellaneous study characteristics were extracted.

RESULTS

The search yielded 5561 results, of which 39 met the eligibility criteria. Three diagnostic scores, namely the EROS-CLINICAL, EROS-SIMPLIFIED, and EROS-COMPLETE scores (EROS = Endocrine and Metabolic Responses on Overtraining Syndrome study), were identified. Additionally, basal hormone, neurotransmitter and other metabolite levels, hormonal responses to stimuli, psychological questionnaires, exercise tests, heart rate variability, electroencephalography, immunological and redox parameters, muscle structure, and body composition were reported as potentially diagnostic for OTS.

CONCLUSION

Specific hormones, neurotransmitters, and metabolites, as well as psychological, electrocardiographic, electroencephalographic, and immunological patterns were identified as potentially diagnostic for OTS, reflecting its multisystemic nature. As exemplified by the EROS scores, combinations of these variables may be required to diagnose OTS. These scores must now be validated in larger samples and within female athletes.

Overtraining Syndrome as a Complex Systems Phenomenon

The phenomenon of reduced athletic performance following sustained, intense training (Overtraining Syndrome, and OTS) was first recognized more than 90 years ago. Although hundreds of scientific publications have focused on OTS, a definitive diagnosis, reliable biomarkers, and effective treatments remain unknown. The present review considers existing models of OTS, acknowledges the individualized and sport-specific nature of signs/symptoms, describes potential interacting predisposing factors, and proposes that OTS will be most effectively characterized and evaluated via the underlying complex biological systems. Complex systems in nature are not aptly characterized or successfully analyzed using the classic scientific method (i.e., simplifying complex problems into single variables in a search for cause-and-effect) because they result from myriad (often non-linear) concomitant interactions of multiple determinants. Thus, this review 1) proposes that OTS be viewed from the perspectives of complex systems and network physiology, 2) advocates for and recommends that techniques such as trans-omic analyses and machine learning be widely employed, and 3) proposes evidence-based areas for future OTS investigations, including concomitant multi-domain analyses incorporating brain neural networks, dysfunction of hypothalamic-pituitary-adrenal responses to training stress, the intestinal microbiota, immune factors, and low energy availability. Such an inclusive and modern approach will measurably help in prevention and management of OTS.

A portable droplet microfluidic device for cortisol measurements using a competitive heterogeneous assay

Point-of-care monitoring of chemical biomarkers in real-time holds great potential in rapid disease diagnostics and precision medicine. However, monitoring is still rare in practice, as the measurement of biomarkers often requires time consuming and labour intensive assay procedures such as enzyme linked immunosorbent assay (ELISA), which pose a challenge to an autonomous point-of-care device. This paper describes a prototype device capable of performing ELISA autonomously and repeatedly in a high frequency using droplet microfluidics. Driven by a specially designed peristaltic pump, the device can collect liquid samples from a reservoir, produce trains of droplets, complete magnetic bead based ELISA protocols and provide readouts with colourimetric measurement. Here, cortisol was chosen as a target analyte as its concentration in the human body varies on a circadian rhythm which may be perturbed by disease. The prototype device draws in and analyses 350 nL of the sample containing free bioactive cortisol every 10 seconds, with a sample-to-signal time of 10 minutes, and measures favourably in the analytical range of 3.175-100 ng ml-1, with reliably lower variability compared with the well plate based assay. As most ELISA type assays share similar procedures, we envisage that this approach could form a platform technology for measurement or even continuous monitoring of biomarkers in biological fluids at the point-of-care.

Evaluating Stress in Riding Horses: Part One-Behavior Assessment and Serum Cortisol

Stress can impact the health and well-being of animals negatively. Behavioral and physiological changes, particularly serum cortisol, offer objective and easy-to-use methods of evaluating stress in horses. However, limited studies support a positive relationship between changes in stress-related serum cortisol concentrations and stress-related behaviors in horses. This study assessed differences in stress-related behaviors and serum cortisol concentrations in horses used in a therapeutic riding program (TRH) or university riding program (UNI). Riders were grouped by disability type (TRH) or by experience level (UNI) to determine equine stress impacts. Two trained observers evaluated equine behavior during multiple riding lessons. Behaviors were scored live and via video to assess the accuracy of live scoring. Blood samples for serum cortisol concentrations were collected before, immediately after, and 30 minutes after riding lessons. Serum cortisol concentrations decreased from before to after a riding lesson (TRH, P ≤ .01; UNI, P = .0004) and increased over the course of the study (TRH ≤ 0.0002; UNI, P ≤ .0001). All serum cortisol concentrations remained within or below normal ranges. Overall behavior scores were relatively low in horses participating in both riding programs. Similar behavior scores were observed in horses ridden by novice and experienced riders (P ≥ .1662); however, behavior scores differed in TRH horses ridden by one group of disabled riders during a riding lesson (P ≤ .0431). A relationship between stress-related behavior and cortisol concentration changes was not shown clearly, but data suggest that horses were in a low-stress environment.

Evidence of profound ovarian suppression on combined hormonal contraception resulting in dramatically different ovarian reserve testing and oocyte retrieval outcomes: case report and review of the literature

Objective

To describe a case report and demonstrate that degree of ovarian suppression with continuous combined hormonal contraception (CHC) may be more profound than previously described and may present similarly as decreased ovarian reserve.

Design

Case report and review of the literature.

Setting

Private practice in vitro fertilization center.

Patient(s)

A 36-year-old single gravida 0 presenting for oocyte cryopreservation on CHC.

Intervention(s)

Discontinuation of vaginal ring combined hormonal contraceptive for 6 months.

Main Outcome Measure(s)

Antral follicle count, antimüllerian hormone, day 3 follicle-stimulating hormone, total oocytes, and mature oocytes retrieved before and after discontinuation of CHC.

Result(s)

After a 6-month break from CHC, our patient’s antimüllerian hormone level increased from undetectable levels to 3.45 ng/mL, day 3 follicle-stimulating hormone level decreased from 14.9 IU/mL–6.17 IU/mL, and antral follicle count improved from 0–28. In addition, the number of oocytes retrieved after a 4-month CHC break and 6-month break increased from 8 to 29, respectively.

Conclusion(s)

In patients on long-term combined continuous hormonal contraception, profound ovarian suppression can result in a clinical picture of diminished ovarian reserve and extremely poor response to high-dose stimulation, which may be reversed by more time off from suppression.

Improving the Diagnosis of Nonfunctional Overreaching and Overtraining Syndrome

INTRODUCTION

This study aimed to simplify and optimize the distinction between nonfunctional overreaching (NFO) and overtraining syndrome (OTS) by developing a multivariate approach (discriminant analysis [DA]) including hormonal and psychological changes measured during the Training Optimization (TOP) test.

METHODS

Sensitivity of previously defined cutoff values for hypothalamic-pituitary-adrenal axis hormonal changes were recalculated on a larger database (n = 100). Discriminant analysis including hormonal and psychological variables measured during the TOP test was used to discriminate between NFO and OTS and predict the diagnosis of new cases.

RESULTS

Adrenocorticotrophic hormone (ACTH) and prolactin (PRL) responses to the second exercise test were most sensitive to NFO and OTS. Cutoff values for ACTH and PRL response to the second test (NFO > cutoff value (200%) > OTS), showed a sensitivity of 67% for ACTH and 93% for PRL in case of OTS and 74% for both ACTH and PRL in case of NFO. A DA including hormonal and psychological changes measured during the TOP test, resulted in the accurate diagnosis of NFO and OTS with 98% sensitivity. The ACTH and PRL responses to the first and second exercise tests and feeling of fatigue were the most discriminating variables.

CONCLUSIONS

The ACTH and PRL responses during the TOP test are the most sensitive markers to discriminate between NFO and OTS. Discriminant analysis including hormonal and psychological responses during the TOP test, can be used to optimize the diagnosis of NFO and OTS.

Changes in serum cortisol and some innate immunity parameters after exhaustive exercise in male dogs

The aim of the present study was to investigate the influence of exhaustive exercise on some innate immunity parameters and cortisol levels. Twelve male, mongrel dogs were divided into an experimental group, submitted to prolonged, strenuous exercise with exhaustion as the end-point, and a control group without any exposure to exercise. Serum cortisol levels were measured before exercise (BE), right after (0 h) and on 2nd hour and 4th hour after exercise. The neutrophil function (phagocytosis, phagocytic index, hydrogen peroxide production-H2O2) and classical pathway of complement activation (CPCA) were measured as followеd: BE, right after exercise and on 2, 4, 24, 48, 72 h, and 7, 14 day after exercise. In experimental animals cortisol decreased on hour 4 after exercise (P<0.05), compared to BE level, and on hour 2, compared to controls (P<0.05). Percentage of H2O2 producing neutrophils in experimental animals dropped significantly on hour 4 and day 7 after exercise (P<0.05), compared to BE level and on hour 4 (P<0.01) vs control group. Percentage of phago-cytising neutrophils decreased slightly on hour 48 (P<0.05), compared to BE level. Phagocytic index and CPCA had an insignificant increase after exercise. Inappropriate changes in cortisol levels could indicate inadequate adaptive response to exercise. Overtraining could make animals more susceptible to infection.

The effects of intensified training on resting metabolic rate (RMR), body composition and performance in trained cyclists

Background

Recent research has demonstrated decreases in resting metabolic rate (RMR), body composition and performance following a period of intensified training in elite athletes, however the underlying mechanisms of change remain unclear. Therefore, the aim of the present study was to investigate how an intensified training period, designed to elicit overreaching, affects RMR, body composition, and performance in trained endurance athletes, and to elucidate underlying mechanisms.

Method

Thirteen (n = 13) trained male cyclists completed a six-week training program consisting of a “Baseline” week (100% of regular training load), a “Build” week (~120% of Baseline load), two “Loading” weeks (~140, 150% of Baseline load, respectively) and two “Recovery” weeks (~80% of Baseline load). Training comprised of a combination of laboratory based interval sessions and on-road cycling. RMR, body composition, energy intake, appetite, heart rate variability (HRV), cycling performance, biochemical markers and mood responses were assessed at multiple time points throughout the six-week period. Data were analysed using a linear mixed modeling approach.

Results

The intensified training period elicited significant decreases in RMR (F_(5,123.36) = 12.0947, p = <0.001), body mass (F_(2,19.242) = 4.3362, p = 0.03), fat mass (F_(2,20.35) = 56.2494, p = <0.001) and HRV (F_(2,22.608) = 6.5212, p = 0.005); all of which improved following a period of recovery. A state of overreaching was induced, as identified by a reduction in anaerobic performance (F_(5,121.87) = 8.2622, p = <0.001), aerobic performance (F_(5,118.26) = 2.766, p = 0.02) and increase in total mood disturbance (F_{(5, 110.61)} = 8.1159, p = <0.001).

Conclusion

Intensified training periods elicit greater energy demands in trained cyclists, which, if not sufficiently compensated with increased dietary intake, appears to provoke a cascade of metabolic, hormonal and neural responses in an attempt to restore homeostasis and conserve energy. The proactive monitoring of energy intake, power output, mood state, body mass and HRV during intensified training periods may alleviate fatigue and attenuate the observed decrease in RMR, providing more optimal conditions for a positive training adaptation.

Body composition, metabolism, sleep, psychological and eating patterns of overtraining syndrome: Results of the EROS study (EROS-PROFILE)

Overtraining syndrome (OTS) is caused by an imbalance between training, nutrition and resting, and leads to decreased performance and fatigue; however, the precise underlying triggers of OTS remain unclear. This study investigated the body composition, metabolism, eating, sleeping patterns and mood states among participants with OTS. Selected participants were divided into OTS-affected athletes (OTS, n = 14), healthy athletes (ATL, n = 25), and healthy non-physically active controls (NCS, n = 12). Compared to ATL, OTS showed decreased sleep quality (p = 0.004); increased duration of work or study (p < 0.001); decreased libido (p = 0.024); decreased calorie (p < 0.001), carbohydrate (p < 0.001) and protein (p < 0.001) intakes; decreased mood states (p < 0.001); decreased basal metabolic rate (p = 0.013) and fat burning (p < 0.001); increased body fat (p = 0.006); decreased muscle mass (p = 0.008); and decreased hydration (p < 0.001). Levels were similar between OTS and NCS, except for worsened fatigue (p < 0.001) and vigour (p = 0.001) in OTS. Reduced calorie intake, worsened sleep, and increased cognitive activity are likely OTS triggers. OTS appears to induce dehydration, increase body fat, decrease libido, and worsen mood.

Hypothalamic-Pituitary-Adrenal (HPA) Axis Functioning in Overtraining Syndrome: Findings from Endocrine and Metabolic Responses on Overtraining Syndrome (EROS)-EROS-HPA Axis

BACKGROUND

Overtraining syndrome (OTS) results from excessive training load without adequate recovery and leads to decreased performance and fatigue. The pathophysiology of OTS in athletes is not fully understood, which makes accurate diagnosis difficult. Previous studies indicate that alterations in the hypothalamus-pituitary-adrenal (HPA) axis may be responsible for OTS; however, the data is not conclusive. This study aimed to compare, through gold standard and exercise-independent tests, the response of the HPA axis in OTS-affected athletes (OTS group) to healthy physically active subjects (ATL group) and healthy non-active subjects (NCS group).

METHODS

Selected subjects were evaluated for cortisol response to a 250-μg cosyntropin stimulation test (CST), cortisol and adrenocorticotropic hormone (ACTH) responses during an insulin tolerance test (ITT), and salivary cortisol rhythm (SCR).

RESULTS

A total of 51 subjects were included (OTS, n = 14; ATL, n = 25; and NCS, n = 12). Cortisol response in the CST was similar among the three groups. Conversely, mean cortisol response during an ITT was significantly higher in ATL (21.7 μg/dL; increase = 9.2 μg/dL) compared to OTS (17.9 μg/dL; 6.3 μg/dL) and NCS (16.9 μg/dL; 6.0 μg/dL) (p ≤ 0.001; p = 0.01). Likewise, median ACTH response during an ITT was significantly higher in ATL (91.4 pg/mL; increase = 45.1 pg/mL) compared to OTS (30.3 pg/mL; 9.7 pg/mL) and NCS (51.4 pg/mL; 38.0 pg/mL) (p = 0.006; p = 0.004). For SCR, mean cortisol 30 min after awakening was significantly higher in ATL (500 ng/dL) compared to OTS (323 ng/dL) and NCS (393 ng/dL) (p = 0.004). We identified the following cutoffs that could help exclude or confirm OTS: cortisol level at 30 min after awakening (exclusion = > 530 ng/dL); cortisol response to ITT (exclusion = > 20.5 μg/dL; confirmation = < 17 μg/dL or increase < 9.5 μg/dL); and ACTH response (exclusion = > 106 pg/mL or increase > 70 pg/mL; confirmation = < 35 pg/mL and increase < 14.5 pg/mL).

CONCLUSION

The findings of the present study showed that healthy athletes disclose adaptions to exercises that helped improve sport-specific performance, whereas this sort of hormonal conditioning was at least partially lost in OTS, which may explain the decrease in performance in OTS.

Hormonal aspects of overtraining syndrome: a systematic review

BACKGROUND

Overtraining syndrome (OTS), functional (FOR) and non-functional overreaching (NFOR) are conditions diagnosed in athletes with decreased performance and fatigue, triggered by metabolic, immune, hormonal and other dysfunctions and resulted from an imbalance between training stress and proper recovery. Despite previous descriptions, there is a lack of a review that discloses all hormonal findings in OTS/FOR/NFOR. The aim of this systematic review is to evaluate whether and which roles hormones play in OTS/FOR/NFOR.

METHODS

A systematic search up to June 15^th, 2017 was performed in the PUBMED, MEDLINE and Cochrane databases following PRISMA protocol, with the expressions: (1)overtraining, (2)overreaching, (3)overtrained, (4)overreached, or (5)underperformance, and (plus) (a)hormone, (b)hormonal, (c)endocrine, (d)adrenal, (e)cortisol, (f)GH, (g)ACTH, (h)testosterone, (i)IGF-1, (j)TSH, (k)T4, (l)T3, (m)LH, (n)FSH, (o)prolactin, (p) IGFBP-3 and related articles.

RESULTS

A total of 38 studies were selected. Basal levels of hormones were mostly normal in athletes with OTS/FOR/NFOR compared with healthy athletes. Distinctly, stimulation tests, mainly performed in maximal exercise conditions, showed blunted GH and ACTH responses in OTS/FOR/NFOR athletes, whereas cortisol and plasma catecholamines showed conflicting findings and the other hormones responded normally.

CONCLUSION

Basal hormone levels are not good predictor but blunted ACTH and GH responses to stimulation tests may be good predictors of OTS/FOR/NFOR.

Changes in cytokines, leptin, and IGF-1 levels in overtrained athletes during a prolonged recovery phase: A case-control study

We investigated how cytokines are implicated with overtraining syndrome (OTS) in athletes during a prolonged period of recovery. Plasma IL-6, IL-10, TNF-α, IL-1β, adipokine leptin, and insulin like growth factor-1 (IGF-1) concentrations were measured in overtrained (OA: 5 men, 2 women) and healthy control athletes (CA: 5 men, 5 women) before and after exercise to volitional exhaustion. Measurements were conducted at baseline and after 6 and 12 months. Inflammatory cytokines did not differ between groups at rest. However, resting leptin concentration was lower in OA than CA at every measurement (P < 0.050) but was not affected by acute exercise. Although IL-6 and TNF-α concentrations increased with exercise in both groups (P < 0.050), pro-inflammatory IL-1β concentration increased only in OA (P < 0.050) and anti-inflammatory IL-10 was greater in CA (P < 0.001). In OA, exercise-related IL-6 and TNF-α induction was enhanced during the follow-up (P < 0.050). IGF-1 decreased with exercise in OA (P < 0.050); however, no differences in resting IGF-1 were observed. In conclusion, low leptin level at rest and a pro-inflammatory cytokine response to acute exercise may reflect a chronic maladaptation state in overtrained athletes. In contrast, the accentuation of IL-6 and TNF-α responses to acute exercise seemed to associate with the progression of recovery from overtraining.

The importance of the training-induced decrease in basal cortisol concentration in the improvement in muscular performance in humans

Acute exercise-induced changes in cortisol concentration (C) and training related adaptation within hypothalamic-pituitary-adrenal (HPA) axis has been widely examined, but their influence on muscle strength performance is at best uncertain. Twenty four young healthy men were randomly assigned to an endurance training group (ET, n=12) or to a non-exercising controls (CON, n=12). ET performed supervised endurance training on cycle ergometer for 20 weeks. Endurance training program improved exercise capacity (14 % increase in power output generated at peak oxygen uptake - VO(2peak)), muscle strength performance (increase in MVC - maximal voluntary contraction - by 9 % and in TTF 50 % MVC - time to fatigue at 50 % MVC - by 21 %) and led to a decrease in basal serum C concentration (P=0.006) and an increase in basal testosterone to cortisol (T/C) and free testosterone to cortisol (fT/C) ratios (P=0.01 and P=0.02, respectively). It was found that the decrease in C concentration (deltaC) was positively correlated to the increase in local muscular endurance (deltaTTF 50 % MVC). No significant hormonal changes were seen in CON group. It is concluded that greater decrease in cortisol concentration after the endurance training is accompanied by poorer improvement in skeletal muscle performance in previously untrained subjects.

Exercise and the Regulation of Endocrine Hormones

The endocrine system has profound regulatory effects within the human body and thus the ability to control and maintain appropriate function within many physiological systems (i.e., homeostasis). The hormones associated with the endocrine system utilize autocrine, paracrine, or endocrine actions on the cells of their target tissues within these physiologic systems to adjust homeostasis. The introduction of exercise as a stressor to disrupt homeostasis can greatly amplify and impact the actions of these hormones. To that end, the endocrine response to an acute exercise session occurs in a progression of phases with the magnitude of the response being relative to the exercise work intensity or volume. Various physiologic mechanisms are considered responsible for these responses, although not all are completely understood or elucidated. Chronic exercise training does not eliminate the acute exercise response but may attenuate the overall effect of the responsiveness as the body adapts in a positive fashion to the training stimulus. Regrettably, an excessive intensity and/or volume of training may lead to maladaptation and is associated with inappropriate endocrine hormonal responses. The mechanisms leading to a deleterious maladaptive state are not well understood and require additional research for elucidation.

Heart rate variability reflects training load and psychophysiological status in young elite gymnasts

In gymnastics, monitoring of the training load and assessment of the psychophysiological status of elite athletes is important for training planning and to avoid overtraining, consequently reducing the risk of injures. The aim of this study was to examine whether heart rate variability (HRV) is a valuable tool to determine training load and psychophysiological status in young elite gymnasts. Six young male elite gymnasts took part in a 10-week observational study. During this period, beat-to-beat heart rate intervals were measured every training day in weeks 1, 3, 5, 7, and 9. Balance, agility, upper limb maximal strength, lower limb explosive, and elastic power were monitored during weeks 2, 4, 6, 8, and 10. Training load of each training session of all 10 weeks was assessed by session rating of perceived exertion (RPE) and psychophysiological status by Foster's index. Morning supine HRV (HF% and LF%/HF%) correlated with the training load of the previous day (r = 0.232, r = -0.279, p < 0.05 ). Morning supine to sitting HRV difference (mean R wave to R wave interval (RR), mean heart rate, HF%, SD1) correlated with session RPE of the previous day (r = -0.320, r = 0.301, p < 0.01; r = 0.265, r = -0.270, p < 0.05) but not with Foster's index. Training day/reference day HRV difference (mean RR, SD1) showed the best correlations with session RPE of the previous day (r = -0.384, r = -0.332, p < 0.01) and Foster's index (r = -0.227, r = -0.260, p < 0.05). In conclusion, HRV, and in particular training day/reference day mean RR difference or SD1 difference, could be useful in monitoring training load and psychophysiological status in young male elite gymnasts.

Salivary cortisol and testosterone responses to high-intensity cycling before and after an 11-day intensified training period

This study examined salivary cortisol and testosterone responses to two, different high-intensity, ∼30-min cycles separated by 2 h rest before and after an 11-day intensified training period. Twelve recreationally active, healthy males completed the study. Saliva samples were collected before, immediately after and 30 min after both bouts with salivary cortisol and testosterone concentrations assessed. Compared with pre-training blunted exercise-induced salivary cortisol, testosterone and cortisol/testosterone responses to both bouts post-training were observed (P < 0.05 for all). Comparing pre- with post-training the absolute exercise-induced salivary cortisol, testosterone and cortisol/testosterone decreased from 11.1 to 3.1 and 7.0 to 4.4 nmol · L⁻¹ (cortisol), from 407 to 258 and from 473 to 274 pmol · L⁻¹ (testosterone) and from 12 to 4 and 7 to 5 (cortisol/testosterone) for the first and second bouts, respectively (P < 0.05). No differences in the pre- and post-training rating of perceived exertion (RPE) and heart rate (HR) responses during the cycles or times to fatigue were found (P > 0.05). Fatigue and Burnout scores were higher post- compared with pre-training (P < 0.05). These high-intensity exercise bouts can detect altered hormonal responses following intensified training. This test could assess an athlete's current hormonal status, reductions in salivary cortisol and testosterone responses suggestive of increased fatigue.

Prevention, diagnosis, and treatment of the overtraining syndrome: joint consensus statement of the European College of Sport Science and the American College of Sports Medicine

Successful training not only must involve overload but also must avoid the combination of excessive overload plus inadequate recovery. Athletes can experience short-term performance decrement without severe psychological or lasting other negative symptoms. This functional overreaching will eventually lead to an improvement in performance after recovery. When athletes do not sufficiently respect the balance between training and recovery, nonfunctional overreaching (NFOR) can occur. The distinction between NFOR and overtraining syndrome (OTS) is very difficult and will depend on the clinical outcome and exclusion diagnosis. The athlete will often show the same clinical, hormonal, and other signs and symptoms. A keyword in the recognition of OTS might be "prolonged maladaptation" not only of the athlete but also of several biological, neurochemical, and hormonal regulation mechanisms. It is generally thought that symptoms of OTS, such as fatigue, performance decline, and mood disturbances, are more severe than those of NFOR. However, there is no scientific evidence to either confirm or refute this suggestion. One approach to understanding the etiology of OTS involves the exclusion of organic diseases or infections and factors such as dietary caloric restriction (negative energy balance) and insufficient carbohydrate and/or protein intake, iron deficiency, magnesium deficiency, allergies, and others together with identification of initiating events or triggers. In this article, we provide the recent status of possible markers for the detection of OTS. Currently, several markers (hormones, performance tests, psychological tests, and biochemical and immune markers) are used, but none of them meet all the criteria to make their use generally accepted.

Night and postexercise cardiac autonomic control in functional overreaching

The purpose of this study was to evaluate the effect of a 2-week overload period immediately followed by a 1-week taper period on the autonomic control of heart rate during the night or after exercise cessation. Eleven male endurance athletes increased their usual training volume by 100% for 2 weeks (overload) and decreased it by 50% for 1 week (taper). A maximal graded exercise test and a constant-speed test at 85% of peak treadmill speed, both followed by a 10-min passive recovery period, were performed at baseline and after each period. Heart rate variability was also measured during a 4-h period in the night or during estimated slow-wave sleep. All participants were considered to be overreached based on performance and physiological and psychological criteria. We found a decrease in cardiac parasympathetic control during slow-wave sleep (HFnu = 61.3% ± 11.7% vs 50.0% ± 10.1%, p < 0.05) but not during the 4-h period, as well as a faster heart rate recovery following the maximal graded exercise test (τ = 61.8 ± 14.5 s vs 54.7 ± 9.0 s, p < 0.05) but not after the constant-speed test, after the overload period. There was a return to baseline for both measures after the taper period. Other indices of cardiac autonomic control were not altered by the overload period. Care should be taken in selecting the most sensitive heart rate measures in the follow-up of athletes, because cardiac autonomic control is not affected uniformly by overload training.

Effects of intensified training and subsequent reduced training on glucose metabolism rate and peripheral insulin sensitivity in Standardbreds

OBJECTIVE

To determine the influence of intensified training and subsequent reduced training on glucose metabolism rate and peripheral insulin sensitivity in horses and identify potential markers indicative of early overtraining.

ANIMALS

12 Standardbred geldings.

PROCEDURES

Horses underwent 4 phases of treadmill-based training. In phase 1, horses were habituated to the treadmill. In phase 2, endurance training was alternated with high-intensity exercise training. In phase 3, horses were divided into control and intensified training groups. In the intensified training group, training intensity, duration, and frequency were further increased via a protocol to induce overtraining; in the control group, these factors remained unaltered. In phase 4, training intensity was reduced. Standardized exercise tests were performed after each phase and hyperinsulinemic euglycemic clamp (HEC) tests were performed after phases 2, 3, and 4.

RESULTS

10 of 12 horses completed the study. Dissociation between mean glucose metabolism rate and mean glucose metabolism rate-to-plasma insulin concentration ratio (M:I) was evident in the intensified training group during steady state of HEC testing after phases 3 and 4. After phase 4, mean glucose metabolism rate was significantly decreased (from 31.1 ± 6.8 μmol/kg/min to 18.1 ± 3.4 μmol/kg/min), as was M:I (from 1.05 ± 0.31 to 0.62 ± 0.17) during steady state in the intensified training group, compared with phase 3 values for the same horses.

CONCLUSIONS AND CLINICAL RELEVANCE

Dissociation between the glucose metabolism rate and M:I in horses that underwent intensified training may reflect non-insulin-dependent increases in glucose metabolism.

Are There Useful Physiological or Psychological Markers for Monitoring Overload Training in Elite Rowers?

There is a need for markers that would help determine when an athlete’s training load is either insufficient or excessive. In this study we examined the relationship between changes in performance and changes in physiological and psychological markers during and following a period of overload training in 10 female and 10 male elite rowers. Change in performance during a 4-wk overload was determined with a weekly 30-min time-trial on a rowing ergometer, whereas an incremental test provided change in lactate-threshold power between the beginning of the study and following a 1-wk taper after the overload. Various psychometric, steroid-hormone, muscle-damage, and inflammatory markers were assayed throughout the overload. Plots of change in performance versus the 4-wk change in each marker were examined for evidence of an inverted-U relationship that would characterize undertraining and excessive training. Linear modeling was also used to estimate the effect of changes in the marker on changes in performance. There was a suggestion of an inverted U only for performance in the incremental test versus some inflammatory markers, due to the relative underperformance of one rower. There were some clear linear relationships between changes in markers and changes in performance, but relationships were inconsistent within classes of markers. For some markers, changes considered to predict excessive training (eg, creatine kinase, several proinflammatory cytokines) had small to large positive linear relationships with performance. In conclusion, some of the markers investigated in this study may be useful for adjusting the training load in individual elite rowers.

Altered oxidative stress in overtrained athletes

The purpose of the present study was to examine the relationship between oxidative stress and overtraining syndrome. Indicators of oxidative stress (plasma protein carbonyls, nitrotyrosine, and malondialdehyde) and antioxidant status (oxygen radical absorbance capacity) were measured in severely overtrained (two women, five men) and control athletes (five women, five men). Samples were collected from both groups at baseline (i.e. in the overtraining state of overtrained athletes) and after 6 months of recovery, both at rest and immediately after an exercise test to volitional exhaustion. At baseline, overtrained athletes had higher plasma protein carbonyls at rest than controls (mean difference 0.03 nmol . mg(-1), 95% CI = 0.01-0.05 nmol . mg(-1), P = 0.003, effect size = 0.40). Both at baseline and after recovery, exercise to exhaustion led to an increase in oxygen radical absorbance capacity and malondialdehyde (P = 0.001-0.006) in the controls but not in the overtrained athletes. Furthermore, at baseline, only overtrained athletes showed negative correlations between oxygen radical absorbance capacity at rest and protein carbonyls after exhaustive exercise (r = -0.98, P = 0.0001). These results suggest that increased oxidative stress has a role in the pathophysiology of overtraining syndrome. The attenuated responses of oxidative stress and antioxidant capacity to exercise in the overtrained state could be related to an inability to perform exercise effectively and impaired adaptation to exercise.

Psychological correlates of performance in female athletes during a 12-week off-season strength and conditioning program

Examination of the relationship between performance testing and psychological measures before and after a 12-week strength and conditioning program was the study's purpose. Female NCAA Division-III soccer (n = 28), field hockey (n = 28), and softball (n = 19) athletes completed pre- and post-testing held 12 weeks apart. On day 1, athletes completed informed consent, 3 psychological measures (Profile of Mood States [POMS], Physical Self Perception Profile [PSPP], and Athlete's Self Perception of Physical Abilities [ASPPA]), and 2 strength tests (1 repetition maximum [1RM] bench, 1RM back squat). Day 2 consisted of the 30-yd sprint, pro agility run (PRO), vertical jump (VJ), and standing long jump (SLJ). All sports improved (p < 0.01) in 1RM bench and squat and reported increases in perceived Physical Strength on the PSPP (p < 0.01). Soccer athletes improved (p < 0.01) in VJ, SLJ, and PRO (p < 0.05). No differences were found in POMS scores. The POMS scores indicated that the athletes were not overtrained or experiencing staleness. A series of correlations showed relationships between physical and psychological measures. Specifically, Physical Strength was correlated with 1RM upper-body (r = 0.49, p < 0.01) and lower-body (r = 0.42, p < 0.01) strength. The PSPP Physical Strength was correlated with ASPPA ratings of upper-body (r = 0.68, p < 0.01) and lower-body (r = 0.57, p < 0.01) strength. The PSPP Sport Competence correlated with ASPPA ratings of power (r = 0.45, p < 0.01) and PRO (r = 0.38, p < 0.05). The study's results highlight the benefits of strength and conditioning. Furthermore, these results demonstrate how physical changes are related to athletes' physical self-perceptions and self-assessment of ability within their teams.

Hypogonadism in men with erectile dysfunction may be related to a host of chronic illnesses

The prevalence of hypogonadism has been found to be increased in certain chronic illnesses, especially diabetes, hypertension and obesity. Recently, the prevalence of hypogonadism in primary care practices mirrored that in our population of men with erectile dysfunction (ED). In this study, the prevalence of hypogonadism in nearly 1000 men with ED was tabulated, using a retrospective chart review, and analyzed for association with the various contributing medical and psychological factors. The prevalence of hypogonadism was determined in men with a variety of chronic illnesses, and was further characterized by decade. We observed an association between hypertension (P=0.025), tobacco abuse (P=0.0059), sleep apnea (P=0.0001), work stress (P=0.041) and hypogonadism. These data were further analyzed for the odds ratio and confidence interval (Forest plot), which showed strong association for sleep apnea and work stress. We did not observe any significant association between diabetes, atherosclerosis, alcohol abuse, multiple medications, asthma, seizure disorder, anxiety/depression and hypogonadism (P values for Cochran-Mantel-Haenszel general association were 0.48, 0.97, 0.25, 0.69, 0.22, 0.76 and 0.98, respectively). We suggest that a host of chronic illnesses have a high prevalence of secondary hypogonadism. Men who have chronic medical or psychological illnesses should have their testosterone level checked, especially when sexual dysfunction symptoms or signs are present.

Overtrained horses alter their resting pulsatile growth hormone secretion

The influence of intensified and reduced training on nocturnal growth hormone (GH) secretion and elimination dynamics was studied in young (1.5 yr) Standardbred geldings to detect potential markers indicative for early overtraining. Ten horses trained on a treadmill for 32 wk in age-, breed-, and gender-matched fixed pairs. Training was divided into four phases (4, 18, 6, and 4 wk, respectively): 1) habituation to high-speed treadmill trotting, 2) normal training, in which speed and duration of training sessions were gradually increased, 3) in this phase, the horses were divided into 2 groups: control (C) and intensified trained (IT) group. In IT, training intensity, duration, and frequency were further increased, whereas in control these remained unaltered, and 4) reduced training (RT). At the end of phases 2, 3, and 4, blood was sampled overnight every 5 min for 8 h for assessment of GH secretory dynamics using pulse detection, deconvolution analysis, and approximate entropy (ApEn). Intensified training induced overtraining (performance decreased by 19% compared with C), which was associated with an increase in concentration peaks number (3.6 vs. 2.0, respectively), a smaller peak secretion pattern with a prolonged half-life (15.2 vs. 7.3 min, respectively), and an increased ApEn (0.89 vs. 0.49, respectively). RT did not lead to full recovery for the overtrained horses. The increased irregularity of nocturnal GH pulsatility pattern is indicative of a loss of coordinated control of GH regulation. Longer phases of somatostatin withdrawal are hypothesized to be the underlying mechanism for the observed changes in GH pulsatility pattern.

Recovery training in cyclists: ergometric, hormonal and psychometric findings

This randomized cross-over study aimed at comparing the recovery effect of 4 days of low-intensity, discipline-specific training of 1 vs 3 h daily. Eleven athletes completed two periods of 13 days intensive cycling training (IT), followed by a recovery period consisting of 4 days of low-intensity cycling for either 1 or 3 h each day. Before IT, after IT and after the recovery period, subjects were tested in the laboratory: venous blood sampling, "profile of mood states" (POMS), graded cycling test and a 30-min time trial (TT). Maximal heart rates and lactate concentrations decreased significantly after IT. Peak power output, maximal heart rates and maximal lactate concentrations changed significantly different during the recovery periods. Whereas these parameters were similar to pre-training values after 1-h daily active recovery, 3-h recovery training (REC) led to further decreases. Power output during TT was neither affected by IT nor by both recovery periods. TT-induced increases in cortisol, adrenocorticotropic hormone and prolactin were reduced only after 3-h REC. Total POMS and subscores fatigue and vigor changed significantly different during the recovery periods, a return to pre-training levels after 1 h active recovery and a further deterioration after 3 h REC. It is concluded that low-intensity training of a 1-h duration each day is more appropriate for recovery after an IT period than 3 h.

Psychoendocrine and physical performance responses in male Tunisian rugby players during an international competitive season

The aim was to investigate a follow-up study based on hormonal, physical, and psychological parameters among rugby players who trained during a whole season interspersed with competitions on an international level. Fitness or reciprocally tiredness as well as competitive anxiety were evaluated, respectively, using the French Society for Sports Medicine (SFMS) and the sport competition anxiety test (SCAT) questionnaires. In this study, SFMS and SCAT scores increased respectively over the competitive season. The SFMS score revealed a state of relative tiredness at the end of the season, highlighted by a slight decrement in physical performances. The SCAT score changes are related to the competition context and therefore increased accordingly to the importance of the competition stake. We analyzed the corticotrope and the gonadotrope axis before (T(1)), and at the end of the national and international rugby season (T(2)). Training did not affect the resting salivary cortisol (Csal) levels, but induced a decrease in resting testosterone (Tsal) values, resulting in a dropped T/C ratio. Competition, in both periods (T(1)-T(2)), provoked a significant increase in Csal levels, but the Tsal responses depended on the match stake. Their concentrations increased when the competition generated an important stress and decreased when the psychological conditions remained relatively stable. SFMS is preferentially correlated with resting Csal levels and T/C values measured at 08:00 hr but not with Tsal. SCAT is highly correlated with competitive Csal and Tsal concentrations measured before and after the matches.

Cortisol and GH: odd and controversial ideas

Activation of the hypothalamo-pituitary-adrenal (HPA) axis and of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis represents a physiological response to the energetic, metabolic, vascular, and sometimes neurophysiologic or psychological needs of exercise. Long-lasting increased and (or) decreased secretion of cortisol (the end-product of the HPA axis) or of GH is detrimental to health. This suggests that the activity of these hormonal axes is finely tuned toward homeostasia, tolerating limited prolonged homeostatic disruption. However, the relationships between exercise training and cortisol and GH secretion are full of odd and controversial ideas. In this review, the relationships between HPA axis adaptation to exercise training or disadaptation with overtraining will be discussed, with an emphasis on the limitation on the current measures used to profile hormonal activity. Knowledge of these relationships between cortisol and GH responses to exercise is an important tool to fight against doping with glucocorticoids and GH, and their health-damaging consequences.

Hormonal and psychological adaptation in elite male rowers during prolonged training

In this study, we examined possible hormonal and psychological changes in elite male rowers during a 24-week preparatory period. Eleven elite male rowers were tested on seven occasions over the 6-month training season. Fasting testosterone, growth hormone, cortisol, and creatine kinase activity, together with perceived recovery-stress state were evaluated after a day of rest. Maximal oxygen consumption (VO2max) was determined before and after the training period. Training was mainly organized as low-intensity prolonged training sessions. Significant increases in VO2max (from 6.2 +/- 0.5 to 6.4 +/- 0.6 l x min(-1)) were observed as a result of training. The overall perceived recovery-stress index did not change during the preparatory period. Standardized recovery and stress scores changed during the course of training in comparison with pre-training values. When basal hormone concentrations were compared with the first measurement, significant changes in testosterone and cortisol were observed together with changes in mean weekly training volume. Basal testosterone (r = 0.416; P = 0.010) and cortisol (r = 0.527; P = 0.001) were related to mean weekly training volume. Basal growth hormone did not change during the training. Changes in creatine kinase activity demonstrated similar pattern with changes in mean weekly training volume. The overall perceived recovery-stress index was related to testosterone, cortisol, growth hormone, and creatine kinase activity (r > 0.299; P < 0.015). Our findings indicate that testosterone and cortisol are more sensitive to changes in training volume than either growth hormone or perceived recovery-stress state in elite rowing training. Increases in these stress hormone concentrations represent a positive adaptation to current training load. Significant relationships between hormonal and perceived recovery-stress state suggest that metabolic and psychological changes should be carefully monitored to avoid a negative effect on the training status of elite rowers.

Monitoring and Titrating Symptoms

A key challenge to optimising marathon running performance is to train with adequate frequency, duration and intensity as well as get enough recovery to optimise biological adaptations underlying performance. Some marathon runners train inadequately and underperform, while others perform poorly because they become injured or develop staleness in response to overtraining. Staleness, a depression-like syndrome, could plausibly be caused by overtraining-induced molecular and cellular changes in brain circuits involved in depression or other related mood states such as anger, fatigue, vigor and confusion. The central thesis of this paper is that easily assessed resting and/or exercise symptoms, valid markers of either difficult-to-access, expensive-to-assess or unmeasurable brain circuits, can be used to optimise marathon running performance by helping to avoid either inadequate training or excessive training resulting in staleness. Available models of human performance and relevant data, admittedly incomplete at the present time, suggest that marathon runners may benefit from systematically using symptom responses to training in order to aid in adjusting training loads for the purpose of optimising training. As this approach is better linked with neuroscience and neuroimaging findings, it could be refined and prove to be useful for elite as well as non-elite marathon runners.

β2-Adrenergic receptor downregulation and performance decrements during high-intensity resistance exercise overtraining

Previous research on overtraining due to excessive use of maximal resistance exercise loads [100% 1 repetition maximum (1 RM)] indicates that peripheral muscle maladaptation contributes to overtraining-induced performance decrements. This study examined the cellular and molecular responses of skeletal muscle to performance decrements due to high-relative-intensity (%1 RM) resistance exercise overtraining. Weight-trained men were divided into overtrained (OT, n = 8) and control (Con, n = 8) groups. The OT group performed 10 x 1 at 100% 1 RM daily for 2 wk, whereas the Con group performed normal training 2 days/wk. Muscle biopsies from the vastus lateralis muscle, voluntary static and dynamic muscle performances, and nocturnal urinary epinephrine were assessed before (pre) and after (post) overtraining. Overtraining occurred as indicated by a decrease in 1-RM strength for the OT group (mean +/- SE; OT pre = 159.3 +/- 10.1 kg, OT post = 151.4 +/- 9.9 kg, Con pre = 146.0 +/- 12.9 kg, Con post = 144.9 +/- 13.3 kg), as well as a 36.3% decrease in mean power at 100% 1-RM loads. Normal training could be resumed only after 2-8 wk of training cessation. Muscle beta(2)-adrenergic receptor (beta(2)-AR; fmol/mg protein) density significantly decreased by 37.0% for the OT group and was unchanged for the Con group (-1.8%). Nocturnal urinary epinephrine for the OT group increased by 49%, although this was not significant (effect size = 0.42). The ratio of nocturnal urinary epinephrine to beta(2)-AR density suggested a decreased beta(2)-AR sensitivity for the OT group (2.4-fold increase). Overtraining occurred based on decreased muscular force and power. Desensitization of the beta(2)-AR system suggests that this may be an important contributor to performance decrements due to excessive use of maximal resistance exercise loads.

Value of basal serum cortisol to detect corticosteroid-induced adrenal insufficiency in elite cyclists

The frequent use of glucocorticoids by athletes necessitates testing for adrenal insufficiency because of the risk of death in cases of associated severe stress (trauma, infection). During the 2001 and 2002 sporting seasons, we assessed the value of measuring baseline serum cortisol concentrations and the frequency of corticosteroid use during compulsory medical tests carried out by the French Cycling Federation on 659 elite cyclists (585 men and 74 women); the risk of adrenal insufficiency is negatively correlated with the basal serum cortisol level. Adrenal insufficiency was suspected in 34 cyclists (5.2%; 22 in 2001 and 12 in 2002) on the basis of below normal cortisol concentrations and in three cyclists (in 2001) because they had received corticosteroid treatment. In 2001, 10 of the 25 cyclists convoked underwent baseline follow-up serum cortisol determinations and 15 underwent dynamic exploration of adrenal function with the short ACTH test. Adrenal function was found to be deficient in four of these cyclists, at the limits of the normal range in four and normal in seven. Based on these results, the FFC sent a questionnaire in 2002 to all the cyclists to assess the use of corticosteroid in this population. This survey revealed that 85 of 538 cyclists (15.8%) had received corticosteroid treatment in the previous 3 months. Moreover, 11 of the 12 cyclists (92%) with low basal serum cortisol concentrations had received corticosteroid therapy. These results show that basal serum cortisol is relevant to detect adrenal insufficiency in sportsmen, in particular in cases of values below the normal range. The high frequency of corticosteroid use among elite cyclists, and in particular road cyclists who are at risk of trauma and infection, justifies screening tests to detect adrenal insufficiency.

Stress and the neuroendocrine system: the role of exercise as a stressor and modifier of stress

In this article, the physiological impact of one form of stress - physical exercise - on the neuroendocrine system will be discussed. The specific intent of the review is to present an overview of stress endocrinology, the conceptual models associated with this area of study, and a discourse on the dual role of exercise as both a stressor and a modifier of stress within the neuroendocrine system. These points are addressed with respect to the current research literature dealing with exercise endocrinology in an adult population.

Testosterone and endurance exercise: development of the "exercise-hypogonadal male condition"

During the last 30 years a large number of research studies have been conducted examining reproductive endocrine dysfunction in exercising women. The number of similar studies examining men is still relatively small. Nevertheless, an increasing amount of research studies in men indicate endurance exercise training has significant effects upon the major male reproductive hormone, testosterone, and the hypothalamic-pituitary-testicular axis that regulates reproductive hormones. This review article addresses one reproductive endocrine dysfunction found in exercising men, what has been deemed the "exercise-hypogonadal male condition". Specifically, men with this condition exhibit basal (resting-state) free and total testosterone levels that are significantly and persistently reduced. The exact physiological mechanism inducing the reduction of testosterone is currently unclear, but is postulated to be a dysfunction (or perhaps a readjustment) within the hypothalamic-pituitary-testicular regulatory axis. The time course for the development of the "exercise-hypogonadal condition" or the threshold of exercise training necessary to induce the condition remains unresolved. The potential exists for these reduced testosterone levels within the exercise-hypogonadal male to disrupt and be detrimental to some anabolic or androgenic testosterone-dependent physiological processes. Unfortunately, extremely few research studies have addressed whether such processes are affected, and thus findings are inconclusive. Conversely, the alterations in testosterone levels brought about by endurance exercise training have the potential for cardiovascular protective effects and thus could be beneficial to the health of these men. Current evidence suggests this condition is limited to men who have been persistently involved in chronic endurance exercise training for extended periods of time (i.e., years). Many questions, however, regarding the male reproductive endocrine adaptive process to exercise and exercise training remain unanswered, necessitating the need for further research on this topic.