The unknown mechanism of the overtraining syndrome: clues from depression and psychoneuroimmunology

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.

Monitoring training, performance, biomarkers, and psychological state throughout a competitive season: a case study of a triathlete

INTRODUCTION

Ironman triathletes undergo high workloads during competition preparation which can result in nonfunctional overreaching or overtraining syndrome if not matched with adequate recovery.

PURPOSE

The purpose of this case study was to observe changes in physiological and psychological status over the course of a competitive season in a free-living triathlete.

METHODS

The subject was a 41-year-old triathlete competing in three 113.1-km events. Over the course of a 40-week period, the participant arrived at the laboratory every 4 weeks and underwent body composition testing via air displacement plethysmography, a blood draw for analysis of various biomarkers, and a treadmill-based lactate threshold test. Workload during training and competitions was monitored via a wearable heart rate-monitoring device.

RESULTS

Throughout the season, training volume remained high (12.5 ± 3.4 h/week) and body mass and fat-free mass (FFM) continuously decreased, while biomarkers including cortisol, testosterone, and markers of immunological status exhibited minor changes. Laboratory performance remained relatively consistent, while competition performance continually improved. Following the completion of the competitive period, training volume decreased, FFM remained below baseline levels, free cortisol increased, and both free and total testosterone decreased.

CONCLUSIONS

Workload and recovery seem to have been properly managed throughout the season, evidenced by minimal fluctuations in endocrine and immunological markers. The reason for changes observed in testosterone, cortisol, and body composition following the last competition is unclear, though it may be attributed to changes in stressors and recovery practices outside of training. It is recommended that athletes follow a structured plan during the transition period into the offseason to ensure recovery of physiological state and to set up a productive offseason.

Evaluating the Impact of Probiotic Therapy on the Endocannabinoid System, Pain, Sleep and Fatigue: A Randomized, Double-Blind, Placebo-Controlled Trial in Dancers

Emerging research links the endocannabinoid system to gut microbiota, influencing nociception, mood, and immunity, yet the molecular interactions remain unclear. This study focused on the effects of probiotics on ECS markers-cannabinoid receptor type 2 (CB2) and fatty acid amide hydrolase (FAAH)-in dancers, a group selected due to their high exposure to physical and psychological stress. In a double-blind, placebo-controlled trial (ClinicalTrials.gov NCT05567653), 15 dancers were assigned to receive either a 12-week regimen of Lactobacillus helveticus Rosell-52 and Bifidobacterium longum Rosell-17 or a placebo (PLA: n = 10, PRO: n = 5). There were no significant changes in CB2 (probiotic: 0.55 to 0.29 ng/mL; placebo: 0.86 to 0.72 ng/mL) or FAAH levels (probiotic: 5.93 to 6.02 ng/mL; placebo: 6.46 to 6.94 ng/mL; p > 0.05). A trend toward improved sleep quality was observed in the probiotic group, while the placebo group showed a decline (PRO: from 1.4 to 1.0; PLA: from 0.8 to 1.2; p = 0.07841). No other differences were noted in assessed outcomes (pain and fatigue). Probiotic supplementation showed no significant impact on CB2 or FAAH levels, pain, or fatigue but suggested potential benefits for sleep quality, suggesting an area for further research.

A Narrative Review on Adipose Tissue and Overtraining: Shedding Light on the Interplay among Adipokines, Exercise and Overtraining

Lifestyle factors, particularly physical inactivity, are closely linked to the onset of numerous metabolic diseases. Adipose tissue (AT) has been extensively studied for various metabolic diseases such as obesity, type 2 diabetes, and immune system dysregulation due to its role in energy metabolism and regulation of inflammation. Physical activity is increasingly recognized as a powerful non-pharmacological tool for the treatment of various disorders, as it helps to improve metabolic, immune, and inflammatory functions. However, chronic excessive training has been associated with increased inflammatory markers and oxidative stress, so much so that excessive training overload, combined with inadequate recovery, can lead to the development of overtraining syndrome (OTS). OTS negatively impacts an athlete's performance capabilities and significantly affects both physical health and mental well-being. However, diagnosing OTS remains challenging as the contributing factors, signs/symptoms, and underlying maladaptive mechanisms are individualized, sport-specific, and unclear. Therefore, identifying potential biomarkers that could assist in preventing and/or diagnosing OTS is an important objective. In this review, we focus on the possibility that the endocrine functions of AT may have significant implications in the etiopathogenesis of OTS. During physical exercise, AT responds dynamically, undergoing remodeling of endocrine functions that influence the production of adipokines involved in regulating major energy and inflammatory processes. In this scenario, we will discuss exercise about its effects on AT activity and metabolism and its relevance to the prevention and/or development of OTS. Furthermore, we will highlight adipokines as potential markers for diagnosing OTS.

The reproducibility of dendritic cell and T cell counts to a 30-min high-intensity cycling protocol as a tool to highlight overtraining

Heavy training has been reported to be immunosuppressive in athletes and lead to blunted cortisol responses to exercise. Cortisol elevates the number of dendritic cells (DCs), key antigen-presenting cells that interact with T cells to initiate an immune response. Reproducible cortisol responses to a 30-min cycle test have been identified but were based on percentage of work rate maximum. To ensure physiological consistency, submaximal anchors, that is, ventilatory threshold (VT1 ) should prescribe intensity. This study aims to assess the reproducibility of the DC and T cell responses to an adapted stress test to assess its usefulness in assessing DC dysfunction with intensified training. Twelve males cycled for 1 min at 20% below VT1 and 4 min at 50% between VT1 andV ̇ O 2 max ${\dot{V}}_{{{\mathrm{O}}}_{\mathrm{2}}\max }$ , for 30 min (20/50), with blood samples pre-, post- and 30 min post-exercise. This was repeated twice, 2-7 days apart. Flow cytometry assessed total DCs, plasmacytoid DCs, myeloid DCs, total T cells, T helper cells and T cytotoxic cells. No significant trial or interaction effects were found for any variable. A significant main effect of time for all variables was found; immune cells increased from pre- to post-exercise and decreased to baseline 30 min post-exercise, apart from plasmacytoid DCs, which remained elevated 30 min post-exercise. Intraclass correlation coefficients showed overall good-to-excellent reliability for all immune cells, with smallest real difference and Bland-Altman analysis verifying high reproducibility between trials. These results suggest that the 20/50 exercise test induces reproducible DC and T cell count changes, which, implemented before and after a period of intensified training, may highlight the negative states of overtraining.

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.

Clinical Commentary: Depression and Anxiety in Adolescent and Young Adult Athletes

Mental health (MH) symptoms and disorders are common in adolescents and young adults, and athletes may be at risk due to sport-specific triggers such as injury or illness as well as stressors related to performance, transition, or retirement from sport. Anxiety and depression are reported frequently in this age group, and early recognition and treatment can improve outcomes. The medical team (eg, athletic trainers or therapists, team physicians) should be familiar with the symptoms of depression and anxiety, recognize "red flags" for these symptoms and disorders, and seek to provide screening assessments and develop MH plans and MH emergency action plans. As a part of their scope of practice, team physicians should have the initial assessment and management of patients with these MH conditions and appreciate the importance of referrals to other MH providers with expertise caring for athletes. Athletic trainers are often the first point of contact for athletes who may be experiencing MH symptoms and therefore play a key role in early recognition and referrals to team physicians for early diagnosis and treatment. Additional resources that provide more in-depth information regarding the treatment and management of anxiety and depression are provided herein.

Theory to treatment to theory: Evolving a community-based obesity intervention

Within weight-loss treatments, a better understanding of psychosocial correlates of exercise and controlled eating is required to improve lagging outcomes. Within this two-phase study, women with obesity participating in community-based treatments with educational (Phase 1 n = 57, Phase 2 n = 44) and behavioral (Phase 1 n = 80, Phase 2 n = 53) formats were contrasted on psychosocial variables over 3 and 6 months and their interrelations based on the mood-behavior-model and coaction theory. Phase 1 findings informed curricular extensions in Phase 2. In Phase 1, there were significant overall improvements in total mood disturbance, self-regulation of exercise, self-regulation of eating, and weight, which were more pronounced in the behavioral vs. educational format group (-3.5 % vs. -1.4 % weight loss, respectively). Mediation analyses indicated that change in self-regulation of exercise mediated the prediction of change in self-regulation of eating by mood change. Phase 2 findings were similar; however, effect sizes were greater (-6.2 % vs. -2.9 % weight loss, respectively). Within both phases, increased self-regulation of eating significantly predicted weight reduction. Paths from changes in mood→self-regulation of exercise→self-regulation of eating suggested future program attention focus on treatment-associated mood change reinforcing self-regulation, and self-regulation generalizing from an exercise to eating context. Methods of progressing treatment curricula via theory-testing were suggested.

Pickleball and mental health in adults: A systematic review

Introduction

Physical activity has been extensively studied and numerous mental health benefits have been found. Pickleball is an emerging racquet sport, which is characterized by its accessibility to all audiences and has become especially popular in the United States among the elderly. It is a novel team game and its inclusive nature is innovative for health improvement. The purpose of this systematic review was to review and evaluate existing studies that have examined the effects of pickleball on the mental and psychological health of individuals.

Methods

A systematic review was conducted on articles found in Scopus, PubMed, Elsevier, Web of Science (WoS), PsyINFO, Dialnet, and Elton B. Stephens Company (EBESCO) from 1975 to the present. The keywords used was a five combination between "Pickleball" joint with different terms by the connector AND, the second part of the combo could be "mental disorder" OR "anxiety" OR "depression" OR "psychological health" OR "mental health." Eligibility criteria included: papers focused on pickleball, in English or Spanish, on mental health variables, without establishing an age range. We excluded duplicate works, without access or that did not address the objective of this study.

Results

The search resulted in 63 papers, of which 13 were selected. A total of 90.74% of the population were people over 50 years of age. The results show significant improvements in the different psychological variables measured in pickleball practitioners: personal wellbeing, life satisfaction, depression, stress, happiness, etc., pickleball shows potential as a new tool to work and improve people's mental health.

Conclusions

The pickleball is displayed as an inclusive sport that does not need adaptations, resulting of great interest to be worked in different populations with mental problems.

Too much is too little: Estimating the optimal physical activity level for a healthy mental state

Introduction

Although physical activity and exercise are generally thought to have favorable effects on mental health, excessive physical activity may have unfavorable effects. In this study, the associations between physical activity and the states of mental health with U-shaped dose-response curves were hypothesized, and the ranges of physical activity resulting in optimal effects on mental health were investigated.

Methods

A cross-sectional survey was conducted on 1,237 adult volunteers in 2017 and 2018. Of these volunteers, 526 participants validly answered the self-administered questionnaires asking about physical activity, depression, anxiety, resilience, insomnia vulnerability, and life events. A comparison of mental health measures by physical activity levels and quadratic equation model regressions were performed.

Results

No significant linear associations between physical activity levels and mental health measurements were observed; however, the U-shaped, quadratic equation models indicated a significance. The following levels of physical activity per week optimized the mental health measurements values of the participants: 6,953 MET-minutes and 25.70 h for depression, 5,277 MET-minutes and 21.60 h for state anxiety, 5,678 MET-minutes and 22.58 h for trait anxiety, 25.41 h for resilience, and 9,152 MET-minutes and 31.17 h for insomnia vulnerability.

Conclusion

Physical activities in the optimal range were associated with more favorable mental health measurements. Physical activities that were too much or too long and outside of the optimal range were associated with less favorable mental health measurements.

A Simple Model for Diagnosis of Maladaptations to Exercise Training

Background

The concept of overreaching and super compensation is widely in use by athletes and coaches seeking to maximize performance and adaptations to exercise training. The physiological aspects of acute fatigue, overreaching and non-functional overreaching are, however, not well understood, and well-defined negative physiological outcomes are missing. Instead, the concept relies heavily on performance outcomes for differentiating between the states. Recent advancements in the field of integrated exercise physiology have associated maladaptations in muscular oxidative function to high loads of exercise training.

Method

Eleven female and male subjects that exercised regularly but did not engage in high-intensity interval training (HIIT) were recruited to a 4-week long training intervention where the responses to different training loads were studied. Highly monitored HIIT sessions were performed on a cycle ergometer in a progressive fashion with the intent to accomplish a training overload. Throughout the intervention, physiological and psychological responses to HIIT were assessed, and the results were used to construct a diagnostic model that could indicate maladaptations during excessive training loads.

Results

We here use mitochondrial function as an early marker of excessive training loads and show the dynamic responses of several physiological and psychological measurements during different training loads. During HIIT, a loss of mitochondrial function was associated with reduced glycolytic, glucoregulatory and heart rate responses and increased ratings of perceived exertion in relation to several physiological measurements. The profile of mood states was highly affected after excessive training loads, whereas performance staled rather than decreased. By implementing five of the most affected and relevant measured parameters in a diagnostic model, we could successfully, and in all the subjects, identify the training loads that lead to maladaptations.

Conclusions

As mitochondrial parameters cannot be assessed without donating a muscle biopsy, this test can be used by coaches and exercise physiologists to monitor adaptation to exercise training for improving performance and optimizing the health benefits of exercise.

Clinical trial registry numberNCT04753021. Retrospectively registered 2021-02-12.

Lymphocyte and dendritic cell response to a period of intensified training in young healthy humans and rodents: A systematic review and meta-analysis

Background: Intensified training coupled with sufficient recovery is required to improve athletic performance. A stress-recovery imbalance can lead to negative states of overtraining. Hormonal alterations associated with intensified training, such as blunted cortisol, may impair the immune response. Cortisol promotes the maturation and migration of dendritic cells which subsequently stimulate the T cell response. However, there are currently no clear reliable biomarkers to highlight the overtraining syndrome. This systematic review and meta-analysis examined the effect of intensified training on immune cells. Outcomes from this could provide insight into whether these markers may be used as an indicator of negative states of overtraining. Methods: SPORTDiscus, PUBMED, Academic Search Complete, Scopus and Web of Science were searched until June 2022. Included articles reported on immune biomarkers relating to lymphocytes, dendritic cells, and cytokines before and after a period of intensified training, in humans and rodents, at rest and in response to exercise. Results: 164 full texts were screened for eligibility. Across 57 eligible studies, 16 immune biomarkers were assessed. 7 were assessed at rest and in response to a bout of exercise, and 9 assessed at rest only. Included lymphocyte markers were CD3⁺, CD4⁺ and CD8⁺ T cell count, NK cell count, NK Cytolytic activity, lymphocyte proliferation and CD4/CD8 ratio. Dendritic cell markers examined were CD80, CD86, and MHC II expression. Cytokines included IL-1β, IL-2, IL-10, TNF-α and IFN-γ. A period of intensified training significantly decreased resting total lymphocyte (d= -0.57, 95% CI -0.30) and CD8⁺ T cell counts (d= -0.37, 95% CI -0.04), and unstimulated plasma IL-1β levels (d= -0.63, 95% CI -0.17). Resting dendritic cell CD86 expression significantly increased (d = 2.18, 95% CI 4.07). All other biomarkers remained unchanged. Conclusion: Although some biomarkers alter after a period of intensified training, definitive immune biomarkers are limited. Specifically, due to low study numbers, further investigation into the dendritic cell response in human models is required.

Monitoring Internal Training Intensity Correlated with Neuromuscular and Well-Being Status in Croatian Professional Soccer Players during Five Weeks of the Pre-Season Training Phase

This study aimed to investigate the changes in internal training intensity, well-being, and countermovement jump (CMJ) performance and to determine their relationship across five weeks of the pre-season training phase in professional soccer players. A total of 22 professional male soccer players (age = 21.7 ± 4 years, body height = 185.9 ± 6.3 cm, body weight = 79 ± 6.3 kg, BMI = 22.8 ± 1.4 kg·m−2; VO2max = 52.9 ± 3.2) from the Croatian Second League voluntary participated in this study. The players spent 2230 ± 117 min in 32 technical/tactical and strength/conditioning training sessions, mostly at the low intensity zone (61%), and played 8 friendly matches at a high intensity (>90%). A one-way repeated measure of analysis ANOVA revealed a significant difference between weeks in CMJ performance (F(1,22) = 11.8, p < 0.001), with CMJ height in weeks 4 and 5 being likely to very likely higher than that noted in week 1. Moreover, significant differences between weeks were found in all internal training intensity measures (average [F(1,22) = 74.8, p < 0.001] and accumulated weekly internal training intensity [F(1,22) = 55.4, p < 0.001], training monotony [F(1,22) = 23.9, p < 0.001], and training strain [F(1,22) = 34.5, p < 0.001]). Likewise, differences were observed for wellness status categories (fatigue [F(1,22) = 4.3, p = 0.003], sleep [F(1,22) = 7.1, p < 0.001], DOMS [F(1,22) = 5.7, p < 0.001], stress [F(1,22) = 15.6, p < 0.001]), mood [F(1,22) = 12.7, p < 0.001], and overall well-being status score (F(1,22) = 13.2, p < 0.001). Correlation analysis showed large negative correlations between average weekly internal training intensity and fatigue (r = −0.63, p = 0.002), DOMS (r = −0.61, p = 0.003), and WBI (r = −0.53, p = 0.011). Additionally, fatigue was significantly associated (large negative correlation) with accumulated weekly internal training intensity (r = −0.51, p = 0.014) and training strain (r = −0.61, p = 0.003). Small, but non-significant, correlations were found between CMJ performance and wellness status measures. These findings highlight the utility and simplicity of monitoring tools to improve athletes’ performance.

The Role of Psychologists in Sport Medicine Practice

Young athletes face a unique set of stressors from nonathletes that require careful screening and management. Internalizing disorders, substance use, overtraining, eating disorders, the female athlete triad, and sport-related injury are some psychological issues related to sports participation. Young athletes experiencing these conditions may experience functional impairment and distress on and off the field and management of these concerns includes routine screening and intervention. Embedding a psychologist within a pediatric sports medicine clinic improves patients' access to psychological screenings, early identification, and early intervention for these concerns athletes face.

Associations between Training Load and Well-Being in Elite Beach Soccer Players: A Case Report

The current case study aimed to quantify within-subjects correlations between training load and well-being in elite male beach soccer players. Data were obtained over three consecutive days during the preparation camp for the FIFA Beach Soccer World Cup Russia 2021. The session rating of perceived exertion (s-RPE) and external training load metrics using global positioning system (GPS) were recorded. Eleven players reported perceived well-being (sleep quality, fatigue, muscle soreness and stress) using a Likert scale (Hooper Index) before breakfast. Within-subjects correlation coefficients between workload and well-being were calculated. Workload metrics and perceived well-being indices were significantly lower on day three than on days one and two. The Hooper Index presented a very large positive correlation with s-RPE (r = 0.86 [0.67, 0.94], 95% confidence interval, CI), exposure time (r = 0.88 [0.71, 0.95]), total distance (r = 0.83 [0.60, 0.93]), high-speed distance (r = 0.77 [0.50, 0.91]), and number of sprints (r = 0.75 [0.47, 0.90]). Sleep quality presented a moderate to large positive correlation with s-RPE (r = 0.51 [0.11, 0.77]), exposure time (r = 0.50 [0.10, 0.76]), high-speed distance (r = 0.53 [0.15, 0.78]), number of sprints (r = 0.62 [0.28, 0.83]) and total distance (r = 0.41 [0.18, 0.78]). Fatigue presented a large to very large positive correlation with s-RPE (r = 0.85 [0.66, 0.94]), exposure time (r = 0.90 [0.78, 0.96]), total distance (r = 0.86 [0.68, 0.94]), high-speed distance (r = 0.65 [0.31, 0.84]) and number of sprints (r = 0.56 [0.18, 0.79]). Muscle soreness presented a large to very large positive correlation with s-RPE (r = 0.79 [0.56, 0.91]), exposure time (r = 0.83 [0.62, 0.93]), total distance (r = 0.81 [0.59, 0.92]), high-speed distance (r = 0.75 [0.47, 0.89]) and number of sprints (r = 0.59 [0.22, 0.81]). Overall, workload presented a meaningful correlation with perceived well-being indices in elite male beach soccer players during a training camp. These findings suggest that workload metrics and perceived well-being indices can be implemented into the daily routine of an elite beach soccer team, which may assist coaches, sports scientists, and practitioners in better preparing players for beach soccer competitions.

Extreme duration exercise affects old and younger men differently

Aim & Methods

Extreme endurance exercise provides a valuable research model for understanding the adaptive metabolic response of older and younger individuals to intense physical activity. Here, we compare a wide range of metabolic and physiologic parameters in two cohorts of seven trained men, age 30 ± 5 years or age 65 ± 6 years, before and after the participants travelled ≈3000 km by bicycle over 15 days.

Results

Over the 15‐day exercise intervention, participants lost 2–3 kg fat mass with no significant change in body weight. V̇O₂max did not change in younger cyclists, but decreased (p = 0.06) in the older cohort. The resting plasma FFA concentration decreased markedly in both groups, and plasma glucose increased in the younger group. In the older cohort, plasma LDL‐cholesterol and plasma triglyceride decreased. In skeletal muscle, fat transporters CD36 and FABPm remained unchanged. The glucose handling proteins GLUT4 and SNAP23 increased in both groups. Mitochondrial ROS production decreased in both groups, and ADP sensitivity increased in skeletal muscle in the older but not in the younger cohort.

Conclusion

In summary, these data suggest that older but not younger individuals experience a negative adaptive response affecting cardiovascular function in response to extreme endurance exercise, while a positive response to the same exercise intervention is observed in peripheral tissues in younger and older men. The results also suggest that the adaptive thresholds differ in younger and old men, and this difference primarily affects central cardiovascular functions in older men after extreme endurance exercise.

5-A-SIDE SOCCER: PREVALENCE OF SPORTS INJURIES IN BRAZILIAN TEAM PLAYERS

ABSTRACT Introduction: 5-a-side soccer is a sports modality exclusively for athletes with vision impairment (VI) classified as blind - B1 (Blind 1) by the visual classification process. Type of impairment and high-performance training are factors that contribute to the development of sports injuries. Objective: The purpose of this study was to characterize the prevalence of sports-related injuries in visually disabled athletes of the Brazilian 5-a-side soccer team. Methods: The method was defined as a descriptive, longitudinal, epidemiological study. The sample was composed of ten male athletes, members of the Brazilian 5-a-side soccer team, including two athletes without VI and eight athletes with the B1 visual classification, who participated in competitions in 2014. The questionnaire for the data collection was based on the Sport Injuries Protocol for Paralympic Sports (PLEEP), expressing quantitative data analyzed by descriptive statistics. Results: The results showed that, in 2014, five athletes with VI had seven sports injuries, with a prevalence of 62.5%, clinical incidence of 0.87 injuries per athlete per year, and 1.4 injuries per injured athlete. The main sports injuries were muscle strain (28.6%), groin pull (athletic pubalgia) (28.6%), and shin splints (periostitis) (28.6%). All sports injuries occurred in the lower limbs, affecting legs (71.4%) and hips (28.6%). Overload was the most frequent mechanism (57%), reported after the technical kick movement and linked to the muscle imbalance between dominant and supporting lower limbs, in addition to the postural misalignment typical of people with visual impairments. Conclusions: In summary, the Brazilian 5-a-side soccer athletes presented a pattern of overload injuries resulting from the repetition of the technical kick movement, occurring predominantly in sports competitions. Epidemiological data can contribute to the development of strategies to prevent injuries in this sport. Level of evidence II, Progressive prognostic study.

Sport Psychiatry and Its Research Agenda

Athletes commonly experience mental health symptoms. However, prevalence estimates require refinement so that symptoms are interpreted in context and diagnostic labels are accurately applied. Further prevalence studies are also needed in subgroups within sport, in particular female athletes, athletes with disabilities, and coaches. Existing consensus-based and evidence-based therapies must be adapted not only to the individual athlete but also to the ecology of sports. Filling the gaps in our knowledge on what treatment modifications may be required for the individual athlete and how services should be designed to deliver treatment most effectively will require well-designed studies that use standardized terminology and defined outcome measures.

Perceived Time, Frequency, and Intensity of Engagement and Older Masters Athletes' Subjective Experiences

Masters athletes are a unique group of older adults whose experiences may provide valuable insights into the role of sport for successful aging. The purpose of this study was to explore whether masters athletes' social and psychological experiences vary with their time, frequency, and perceived exertion in training and competition. Semi-structured interviews were conducted with 40 men and women older masters athletes, aged 50–79 years (M = 66), who were active at the competitive level across a variety of sports (e.g., volleyball, curling, rowing, dragon boating, running, swimming, and basketball) at the time of the study. Results indicate that all participants experienced social and psychological benefits from engaging in masters sport. Only the high-frequency engagement subgroup (participating five to seven times per week in training and/or competition) reported social downsides, in terms of missing time with family and friends outside of masters sport. However, some participants described the positive family support (e.g., spouse who endorses sport participation) that overrides some of the social costs. These findings have implications for realizing positive experiences with minimal engagement in masters sport, yet an apparent threshold of participation beyond which negative social consequences may be experienced. This is an important consideration for the design and promotion of sport for older adults.

Relationship Between Heart Rate Variability and Acute:Chronic Load Ratio Throughout a Season in NCAA D1 Men's Soccer Players

ABSTRACT

Sekiguchi, Y, Huggins, RA, Curtis, RM, Benjamin, CL, Adams, WM, Looney, DP, West, CA, and Casa, DJ. Relationship between heart rate variability and acute:chronic load ratio throughout a season in NCAA D1 men's soccer players. J Strength Cond Res 35(4): 1103-1109, 2021-The purpose of this study was twofold: (a) to examine the relationship between heart rate variability (HRV) and acute:chronic workload ratio (ACWR)-based training load (TL) metrics and (b) to examine relationships across various A:C ratio-based TL metrics. Heart rate variability in 23 male college soccer players (mean ± SD; age, 21 ± 1 years; body mass, 80.3 ± 5.8 kg; height, 181.9 ± 6.5 cm; %body fat, 11.9 ± 2.0%; and V̇o2max, 51.9 ± 5.0 ml·kg-1·min-1) was measured at 5 time points: week(W)1, W3, W7, W12, and W14 during the 2015 NCAA men's soccer season. Heart rate variability was calculated from beat to beat intervals using a heart rate monitor. Players donned a global position satellite-enabled device that measured the following TL metrics: session time (ST), Player Load (PL), PL·min-1, and total distance (TD). Acute:chronic workload ratio was calculated for each TL metric: ACWR-based ST (ACWRST), ACWR-based PL (ACWRPL), ACWR-based PL·min-1 (ACWRPLM), and ACWR-based TD (ACWRTD): ACWR = week average TLs/mo average (30 ± 1 days) TLs. Relationships between HRV and ACWR-based each TL metric were evaluated using mixed effects models. Tukey pairwise comparisons were used to examine differences between types of ACWR-based TL metrics. An increase in ACWRST significantly reduced HRV throughout a season (-7.4 ± 3.6 m·s-1; p = 0.04). There were significant differences between ACWRPLM and ACWRST, ACWRPL and ACWRTD at W1, ACWRPLM and ACWRST at W3 (p < 0.05). In conclusion, ACWRST, ACWRPL, and ACWRTD were significantly different from ACWRPLM. ACWRST was found to significantly predict HRV; higher ACWRST was significantly associated with lower HRV. Therefore, tracking of the ACWR using ST may help to optimize athlete's physiological state throughout a season.

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.

Research on the influence of the COVID-19 epidemic on work stress of returning workers in China: A study based on empirical analyses of industrial enterprises

BACKGROUND

The COVID-19 epidemic not only cast a shadow on China's economic development but also caused phased panic and anxiety among the Chinese population. At the stage when the spread of the epidemic is not completely controlled, the business activities will surely cause employees to worry and produce a work stress reaction.

OBJECTIVE

This study explores the impact of psychosocial stress caused by the COVID-19 epidemic on the work stress of returned workers. Furthermore, we explore the boundary conditions for reducing work stress from the perspectives of perceived organizational support, perceived social support and epidemic awareness.

METHODS

Data were collected within two weeks after the Chinese government announced the work resumption of industrial enterprises. During this period, 526 returned workers participated in the study.

RESULTS

The results showed that the psychosocial stress caused by the epidemic had a positive impact on work stress. Both perceived organizational support and perceived that social support can alleviate the impact of psychosocial stress on work stress. The moderating effect of epidemic awareness was only established in non-severe epidemic areas.

CONCLUSIONS

In the current period of the spread of the COVID-19 epidemic, the conclusions of this study have a certain theoretical significance and practical value.

Mental Health in the Young Athlete

PURPOSE OF REVIEW

The goal of the present paper is to provide a comprehensive overview of mental health concerns in young athletes, with a focus on common disorders, as well as population-specific risk factors.

RECENT FINDINGS

Athletes experience similar mental health concerns as non-athlete peers, such as anxiety, depression and suicidal ideation, ADHD, eating disorders, and substance abuse. However, they also experience unique stressors that put them at risk for the development or exacerbation of mental health disorders. Student athletes have to balance academics with rigorous training regimens while focusing on optimal performance and managing high expectations. Physical injuries, overtraining, concussion, sleep disorders, and social identity are some of the factors that also impact the mental health of student athletes. Existing literature highlights the need to develop proactive mental health and wellness education for young athletes, and to develop services that recognize the unique needs of this population.

The Multidisciplinary Process Leading to Return From Underperformance and Sustainable Success in the World's Best Cross-Country Skier

PURPOSE

To investigate the factors associated with underperformance and the subsequent changes in training characteristics and supportive actions when returning to the world's best cross-country skier.

METHODS

The participant is the most decorated winter Olympian, with 8 Olympic gold medals, 18 World Championship titles, and 114 World Cup victories. Training data were categorized by training form (endurance, strength, and speed); intensity (low, moderate, and high); and mode (running, cycling, and skiing/roller skiing). In addition, test data were retrospectively analyzed, and interviews were performed with the participant and her support team.

RESULTS

After the competitive season, the participant had 8 weeks without systematic training and an evaluation process aiming to detect the factors contributing to underperformance. Here physiological, technical, and psychological challenges were detected. As a consequence, the participant included less high-intensity training (1.2 vs 2.1 sessions/wk, P = .011); more moderate-intensity training (0.9 vs 0.4 sessions/wk, P = .016); and more low-intensity training (6.9 vs 5.9 sessions/wk, P = .036) during the general preparation phase but with similar total endurance training load as previous season. In addition, more strength training (1.6 vs 1.1 h/wk, P = .036) and new ski-specific strength exercises were included. Finally, the athlete's autonomy when planning and adjusting training was increased, nontraining stressors were reduced, more frequent testing was included, systematic mental training was initiated, her nutritional strategy was adjusted, and her asthma treatment was optimized.

CONCLUSIONS

Overall, the current case study could be used as a framework for the holistic approach to treating an overtraining condition and for generation of new hypothesis in this exiting area.

Psychological Predictors for Depression and Burnout Among German Junior Elite Athletes

There exists a strong need for research in clinical sport psychology which does not merely gather information on prevalence rates for psychological disorders and case studies of affected athletes. Rather, research should also uncover the underlying psychological variables which increase the risk for depression and burnout in elite athletes. Many studies gather general factors (e.g., gender, injury, sport discipline) and stay on a more descriptive level. Both constructs (burnout and depression) are based on a temporal, stress-related process model assuming the development of either syndrome results from unfavorable personal (e.g., dysfunctional attitudes, perfectionism, negative coping strategies) or environmental (e.g., cohesion) factors coexisting with severe stressors (i.e., chronic stress). Integrating this knowledge, we propose a shared model for depression and burnout in athletes: a sport specific diathesis-stress model. The present longitudinal study assesses data throughout one sporting season to analyze predictors for both constructs in junior elite athletes. Hierarchical multiple linear regression analyses resulted in six predictors for best model fit. The following factors demonstrated a significant impact on predicting (a) burnout or (b) depression scores at the end of the season: dysfunctional attitudes (a and b), coping strategies (a and b), perfectionism (a), recovery (b), stress (a) and the level of depression at onset (b). Variables such as cohesion or attributional style did not significantly predict depression or burnout. The study supports the structure of a process model (diathesis-stress model) for burnout and depression with the assumption of temporal progression. With some vulnerabilities and their temporal, developmental link identified, prevention can become athlete-specific, effective and economical.

Effects of Mongolian Warm Acupuncture on iNOS/NO and Inflammatory Cytokines in the Hippocampus of Chronic Fatigue Rats

The inducible nitric oxide synthase/nitric oxide (iNOS/NO) signaling pathway and inflammatory cytokines play important roles in the pathogenesis of exercise-induced fatigue. Studies have found that Mongolian warm acupuncture (WA) could alleviate exercise-induced fatigue. However, the exact mechanisms underlying its effects remain unclear. In the present study, we investigated the effects of Mongolian WA on iNOS/NO signaling pathway and proinflammatory cytokines in a chronic exhaustive swimming-induced fatigue rat model. Animals were randomly divided into Control group, Ctrl + WA group, Model group, and Model + WA group. The body weight, exhaustive swimming time test, and Morris water maze test were performed before and after the chronic exhaustive swimming. The serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and iNOS were detected by enzyme linked immunosorbent assay (ELISA). The mRNA expressions of IL-1β, IL-6, TNF-α, IFN-γ, and iNOS in the hippocampus were measured by real-time polymerase chain reaction (RT-PCR). Moreover, the protein expression of iNOS in the hippocampus was measured by western blot, and the NO productions in the serum and hippocampus were detected by Griess reaction system. Chronic exhaustive exercise significantly reduced the body weight and exhaustive swimming time, and induced impairment in learning and memory, and which were reversed by WA treatment. Chronic exhaustive exercise also increased the expressions of iNOS and proinflammatory cytokines, while WA treatment significantly decreased the level of iNOS and proinflammatory cytokines. However, chronic exhaustive exercise did not affect the NO production. These findings demonstrated that WA could alleviate the chronic exhaustive swimming-induced fatigue and improve the learning and memory ability, and the actions might be related to the reduction of inflammatory response and iNOS expression.

Hypogonadism in Exercising Males: Dysfunction or Adaptive-Regulatory Adjustment?

For decades researchers have reported men who engaged in intensive exercise training can develop low resting testosterone levels, alterations in their hypothalamic-pituitary-gonadal (HPG) axis, and display hypogonadism. Recently there is renewed interest in this topic since the International Olympic Committee (IOC) Medical Commission coined the term "Relative Energy Deficiency in Sports" (RED-S) as clinical terminology to address both the female-male occurrences of reproductive system health disruptions associated with exercise. This IOC Commission action attempted to move beyond the sex-specific terminology of the "Female Athlete Triad" (Triad) and heighten awareness/realization that some athletic men do have reproductive related physiologic disturbances such as lowered sex hormone levels, HPG regulatory axis alterations, and low bone mineral density similar to Triad women. There are elements in the development and symptomology of exercise-related male hypogonadism that mirror closely that of women experiencing the Triad/RED-S, but evidence also exists that dissimilarities exist between the sexes on this issue. Our research group postulates that the inconsistency and differences in the male findings in relation to women with Triad/RED-S are not just due to sex dimorphism, but that there are varying forms of exercise-related reproductive disruptions existing in athletic men resulting in them displaying a relative hypogonadism condition. Specifically, such conditions in men may derive acutely and be associated with low energy availability (Triad/RED-S) or excessive training load (overtraining) and appear transient in nature, and resolve with appropriate clinical interventions. However, manifestations of a more chronic based hypogonadism that persists on a more permanent basis (years) exist and is termed the "Exercise Hypogonadal Male Condition." This article presents an up-to-date overview of the various types of acute and chronic relative hypogonadism found in athletic, exercising men and proposes mechanistic models of how these various forms of exercise relative hypogonadism develop.

Monitoring Blood Biomarkers and Training Load Throughout a Collegiate Soccer Season

Huggins, RA, Fortunati, AR, Curtis, RM, Looney, DP, West, CA, Lee, EC, Fragala, MS, Hall, ML, and Casa, DJ. Monitoring blood biomarkers and training load throughout a collegiate soccer season. J Strength Cond Res 33(11): 3065-3077, 2019-This observational study aimed to characterize the responses of a comprehensive panel of biomarkers, observed ranges, training load (TL) metrics, and performance throughout the collegiate soccer season (August-November). Biomarkers (n = 92) were collected before the start of pre-season (PS), in-season weeks (W)1, W4, W8, and W12 in NCAA Division I male soccer players (n = 20, mean ± SD; age = 21 ± 1 years, height = 180 ± 6 cm, body mass = 78.19 ± 6.3 kg, body fat = 12.0 ± 2.6%, VO2max 51.5 ± 5.1 ml·kg·min). Fitness tests were measured at PS, and W12 and TL was monitored daily. Changes in biomarkers and performance were calculated via separate repeated-measures analysis of variance. Despite similar fitness (p > 0.05), endocrine, muscle, inflammatory, and immune markers changed over time (p < 0.05). Total and free testosterone was lower in W1 vs. PS, whereas free cortisol remained unchanged at PS, W1, and W4 (>0.94 mg·dL). Oxygen transport and iron metabolism markers remained unchanged except for HCT (W1 vs. PS) and total iron binding capacity (W8-W12 vs. W1). Hepatic markers albumin, globulin, albumin:globulin, and total protein levels were elevated (p < 0.05) at W12 vs. W1, whereas aspartate aminotransferase and alanine aminotransferase levels were elevated at W1-W12 and W8-W12 vs. PS, respectively. Vitamin E, zinc, selenium, and calcium levels were elevated (p < 0.05) at W12 vs. W1, whereas Vitamin D was decreased (p < 0.05). Fatty acids and cardiovascular markers (omega-3 index, cholesterol:high-density lipoprotein [HDL], docosahexenoic acid, low-density lipoprotein [LDL], direct LDL, non-HDL, ApoB) were reduced at W1 vs. PS (p ≤ 0.05). Immune, lipid, and muscle damage biomarkers were frequently outside clinical reference ranges. Routine biomarker monitoring revealed subclinical and clinical changes, suggesting soccer-specific reference ranges. Biomarker monitoring may augment positive adaptation and reduce injuries from stressors incurred during soccer.

Neuro-computational Impact of Physical Training Overload on Economic Decision-Making

Overtraining syndrome is a form of burnout, defined in endurance athletes by unexplained performance drop associated with intense fatigue sensation. Our working hypothesis is that the form of fatigue resulting from physical training overload might share some neural underpinnings with the form of fatigue observed after prolonged intellectual work, which was previously shown to affect the cognitive control brain system. Indeed, cognitive control may be required to prevent any impulsive behavior, including stopping physical effort when it hurts, despite the long-term goal of improving performance through intense training. To test this hypothesis, we induced a mild form of overtraining in a group of endurance athletes, which we compared to a group of normally trained athletes on behavioral tasks performed during fMRI scanning. At the behavioral level, training overload enhanced impulsivity in economic choice, which was captured by a bias favoring immediate over delayed rewards in our computational model. At the neural level, training overload resulted in diminished activation of the lateral prefrontal cortex, a key region of the cognitive control system, during economic choice. Our results therefore provide causal evidence for a functional link between enduring physical exercise and exerting cognitive control. Besides, the concept of cognitive control fatigue bridges the functional consequences of excessive physical training and intellectual work into a single neuro-computational mechanism, which might contribute to other clinical forms of burnout syndromes.

Associations between physical activity intensity and well-being in adolescents

This study aims to explore associations between physical activity intensity and well-being (i.e., positive and negative affect) in adolescents. A secondary aim was to determine if associations were moderated by sex. Grade 8 students from 14 government-funded secondary schools in low socio-economic areas of Western Sydney (Australia) were assessed. Data from three timepoints (baseline, 7-8 months, and 14-15 months) were combined to increase the sample size. Physical activity was objectively assessed for 1-week at each timepoint using Actigraph accelerometers. Time (minutes/day) in light, moderate and vigorous physical activity was estimated. The short form Positive and Negative Affect Scale for Children was used to measure well-being. Quantile regression was used to analyse the data. A total of 3140 observations were collected from 1223 students (mean age at baseline: 12.9(0.54); 55.1% male). Light and moderate physical activity was not associated with well-being. Higher levels of vigorous physical activity were associated with more positive affect [β(SE) = 0.307 (0.06), p < 0.001], to an estimated vigorous physical activity turning point [Point(95%CI) = 36.48 min/day (31.39-41.59)]. Similarly, higher levels of vigorous physical activity were associated with less negative affect [β(SE) = -0.250 (0.06), p < 0.001] up to the estimated vigorous physical activity turning point [Point(95%CI) = 37.35 min/day (31.27-43.44)]. The negative association between vigorous physical activity and negative affect was more pronounced in females than in males. Our findings highlight the importance of adolescents engaging in vigorous physical activity to improve positive affect and reduce negative affect.

A Randomized Controlled Trial Investigating the Effects of Undulatory, Staggered, and Linear Load Manipulations in Aerobic Training on Oxygen Supply, Muscle Injury, and Metabolism in Male Recreational Runners

Background

Taper is considered as a strategy to avoid overtraining and increase peak performance in athletes. Because aerobic exercise increases the level and duration of independence during the lifespan, the participation of recreational athletes has increased in running events around the world. However, the effects of using load reduction in their training and aerobic performance are still not well known.

Objectives

Our goal was to compare load manipulations, using tapering-like periods in the end of recreational athletes training evaluating alterations in oxygen supply, muscle injury, and metabolism markers.

Methods

Healthy males (n = 88, 20–35 years old) were randomly distributed in groups using a combination of two mesocycles of 4 weeks, undulatory and staggered, with two daily microcycles, undulatory and linear. Undulatory-undulatory (Und-Und) and undulatory-linear (Und-Lin) groups had load reduction in the final week of training while the staggered-undulatory (Sta-Und) and staggered-linear (Sta-Lin) groups did not. Cardiorespiratory capacity (V̇O_2max), body mass index (BMI), and body fat % were evaluated. Blood samples were also collected to analyze hematocrit (Ht), mean corpuscular hemoglobin (MCHC), circulating levels of hemoglobin (Hb), creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea (U), cortisol (C), free testosterone (FT), and free T/C ratio.

Results

After 8 weeks of training, Und-Und had the highest trend to increase V̇O_2max. Both Und-Und and Sta-Lin reduced body fat %. Und-Und showed a significant increase in MCHC, T and Free T/C ratio, a positive trend to increase Ht% and Hb levels, and a trend to decrease CK, LDH, and C circulating levels. Sta-Lin presented a trend to decrease Ht% and Hb levels, a significant increase in CK, LDH, AST, ALT circulating levels, and a decrease in Free T/C ratio.

Conclusion

The use of daily undulatory training load provides better gains for aerobic fitness while the use of staggered load, mainly associated with linear load, promotes inadequate recovery in recreational runners.

Ketone ester supplementation blunts overreaching symptoms during endurance training overload

Key points

Overload training is required for sustained performance gain in athletes (functional overreaching). However, excess overload may result in a catabolic state which causes performance decrements for weeks (non‐functional overreaching) up to months (overtraining).

Blood ketone bodies can attenuate training‐ or fasting‐induced catabolic events. Therefore, we investigated whether increasing blood ketone levels by oral ketone ester (KE) intake can protect against endurance training‐induced overreaching.

We show for the first time that KE intake following exercise markedly blunts the development of physiological symptoms indicating overreaching, and at the same time significantly enhances endurance exercise performance.

We provide preliminary data to indicate that growth differentiation factor 15 (GDF15) may be a relevant hormonal marker to diagnose the development of overtraining.

Collectively, our data indicate that ketone ester intake is a potent nutritional strategy to prevent the development of non‐functional overreaching and to stimulate endurance exercise performance.

Abstract

It is well known that elevated blood ketones attenuate net muscle protein breakdown, as well as negate catabolic events, during energy deficit. Therefore, we hypothesized that oral ketones can blunt endurance training‐induced overreaching. Fit male subjects participated in two daily training sessions (3 weeks, 6 days/week) while receiving either a ketone ester (KE, n = 9) or a control drink (CON, n = 9) following each session. Sustainable training load in week 3 as well as power output in the final 30 min of a 2‐h standardized endurance session were 15% higher in KE than in CON (both P < 0.05). KE inhibited the training‐induced increase in nocturnal adrenaline (P < 0.01) and noradrenaline (P < 0.01) excretion, as well as blunted the decrease in resting (CON: −6 ± 2 bpm; KE: +2 ± 3 bpm, P < 0.05), submaximal (CON: −15 ± 3 bpm; KE: −7 ± 2 bpm, P < 0.05) and maximal (CON: −17 ± 2 bpm; KE: −10 ± 2 bpm, P < 0.01) heart rate. Energy balance during the training period spontaneously turned negative in CON (−2135 kJ/day), but not in KE (+198 kJ/day). The training consistently increased growth differentiation factor 15 (GDF15), but ∼2‐fold more in CON than in KE (P < 0.05). In addition, delta GDF15 correlated with the training‐induced drop in maximal heart rate (r = 0.60, P < 0.001) and decrease in osteocalcin (r = 0.61, P < 0.01). Other measurements such as blood ACTH, cortisol, IL‐6, leptin, ghrelin and lymphocyte count, and muscle glycogen content did not differentiate KE from CON. In conclusion, KE during strenuous endurance training attenuates the development of overreaching. We also identify GDF15 as a possible marker of overtraining.

Overload training is required for sustained performance gain in athletes (functional overreaching). However, excess overload may result in a catabolic state which causes performance decrements for weeks (non‐functional overreaching) up to months (overtraining).

Blood ketone bodies can attenuate training‐ or fasting‐induced catabolic events. Therefore, we investigated whether increasing blood ketone levels by oral ketone ester (KE) intake can protect against endurance training‐induced overreaching.

We show for the first time that KE intake following exercise markedly blunts the development of physiological symptoms indicating overreaching, and at the same time significantly enhances endurance exercise performance.

We provide preliminary data to indicate that growth differentiation factor 15 (GDF15) may be a relevant hormonal marker to diagnose the development of overtraining.

Collectively, our data indicate that ketone ester intake is a potent nutritional strategy to prevent the development of non‐functional overreaching and to stimulate endurance exercise performance.

Mental health in elite athletes: International Olympic Committee consensus statement (2019)

Mental health symptoms and disorders are common among elite athletes, may have sport related manifestations within this population and impair performance. Mental health cannot be separated from physical health, as evidenced by mental health symptoms and disorders increasing the risk of physical injury and delaying subsequent recovery. There are no evidence or consensus based guidelines for diagnosis and management of mental health symptoms and disorders in elite athletes. Diagnosis must differentiate character traits particular to elite athletes from psychosocial maladaptations.

Management strategies should address all contributors to mental health symptoms and consider biopsychosocial factors relevant to athletes to maximise benefit and minimise harm. Management must involve both treatment of affected individual athletes and optimising environments in which all elite athletes train and compete. To advance a more standardised, evidence based approach to mental health symptoms and disorders in elite athletes, an International Olympic Committee Consensus Work Group critically evaluated the current state of science and provided recommendations.

Biomarkers of Physiological Responses to Periods of Intensified, Non-Resistance-Based Exercise Training in Well-Trained Male Athletes: A Systematic Review and Meta-Analysis

BACKGROUND

Intensified training is important for inducing adaptations to improve athletic performance, but detrimental performance effects can occur if prescribed inappropriately. Monitoring biomarker responses to training may inform changes in training load to optimize performance.

OBJECTIVE

This systematic review and meta-analysis aimed to identify biomarkers associated with altered exercise performance following intensified training.

METHODS

Embase, MEDLINE, CINAHL, Scopus and SPORTDiscus were searched up until September 2017. Included articles were peer reviewed and reported on biomarkers collected at rest in well-trained male athletes before and after periods of intensified training.

RESULTS

The full text of 161 articles was reviewed, with 59 included (708 participants) and 42 (550 participants) meta-analysed. In total, 118 biomarkers were evaluated, with most being cellular communication and immunity markers (n = 54). Studies most frequently measured cortisol (n = 34), creatine kinase (n = 25) and testosterone (n = 20). Many studies reported decreased immune cell counts following intensified training, irrespective of performance. Moreover, reduced performance was associated with a decrease in neutrophils (d = - 0.57; 95% confidence interval (CI) - 1.07 to - 0.07) and glutamine (d = - 0.37; 95% CI - 0.43 to - 0.31) and an increase in urea concentration (d = 0.80; 95% CI 0.30 to 1.30). In contrast, increased performance was associated with an increased testosterone:cortisol ratio (d = 0.89; 95% CI 0.54 to 1.24). All remaining biomarkers showed no consistent patterns of change with performance.

CONCLUSIONS

Many biomarkers were altered with intensified training but not in a manner related to changes in exercise performance. Neutrophils, glutamine, urea and the testosterone:cortisol ratio exhibited some evidence of directional changes that corresponded with performance changes therefore indicating potential to track performance. Additional investigations of the potential for these markers to track altered performance are warranted.

The proinflammatory effects of chronic excessive exercise

Chronic moderate-intensity exercise is an efficient non-pharmacological strategy to prevent and treat several diseases such as type 2 diabetes mellitus, cardiovascular and chronic obstructive pulmonary diseases, cancers, and Parkinson's disease. On the other hand, improving an athlete's performance requires completing high-intensity and volume exercise sessions. When the delicate balance between high-load exercise sessions and adequate recovery periods is disrupted, excessive training (known as overtraining) can lead to performance decline. The cytokine hypothesis considers that an imbalance involving excessive exercise and inadequate recovery induces musculoskeletal trauma, increasing the production and release of proinflammatory cytokines, mainly interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin 1beta (IL-1beta), which interact with different organic systems, initiating most of the signs and symptoms linked to performance decrement. This leading article used recent data to discuss the scientific basis of Smith's cytokine theory and highlighted that the adverse effects of excessive exercise go beyond performance decline, proposing a multi-organ approach for this issue. These recent insights will allow coaches and exercise physiologists to develop strategies to avoid chronic excessive exercise-induced adverse outcomes.

Men, Mental Health and Elite Sport: a Narrative Review

Mental health in elite sport is receiving more publicity due to an increase in male athletes sharing their personal experiences. Sports injury is recognised as the major risk factor for psychological distress amongst male athletes, although anecdotally this may be that athletes are more likely to discuss their emotional wellbeing when related to the injury they are experiencing. Stress can be amplified within elite sport and the pressure they experience in relation to competition and performance can be exacerbated by adverse life events. This ongoing stress does not end when their sporting career does, it can follow them into retirement. The physical and psychological demands placed upon them by the sporting environment may predispose athletes to developing depression. As an athlete’s symptoms of mental illness intensify, their performance can be negatively affected leaving them vulnerable and exposed to further symptoms of common mental disorders. The pressure of performance can also expose male athletes to overtraining syndrome which can be difficult to distinguish from depression. Male athletes are more vulnerable to eating disorders compared with males in the general population and they do have anxieties, particularly around their bodies, but find it difficult to disclose their concerns. In addition to this, male athletes are more likely to use substances, including opioids to improve both sport and non-sport performance.

Despite the prevalence of common mental disorders in male athletes, stigma still exists, and although some athletes discuss their issues publicly after their career has ended, the majority of athletes prefer to remain silent. There remains a view that athletes who seek help for psychological problems may be seen as weak. Although there is an improvement in help-seeking attitudes within elite sport, further research and education is needed to encourage men to talk about their mental health, share their experiences and to enjoy a greater sense of emotional wellbeing.

INTER SEASON PHYSIOLOGICAL CONTROL OF THE BRAZILIAN BEACH HANDBALL TEAM

ABSTRACT Introduction: The Brazilian national women's beach handball team traditionally holds intense pre-competition training with several daily sessions in the weeks before major matches. This can cause excessive physical strain, but physiological monitoring can guide the coaching staff to modulate the training load, preventing this excessive strain. Objective: To monitor the physiological responses of members of the Brazilian national women's beach handball team in a pre-competition training program with loads modulated according to individual physiological response. Methods: Seventeen athletes (27.1 ± 3.8 years) were assessed before the start of the pre-competition training period (E1), on Day 8 (E2) and Day 18 (E3). Blood samples were taken for subsequent analysis of muscular damage markers (creatine kinase (CK) and lactate dehydrogenase (LDH)). An ECG test was performed to assess cardiac autonomic modulation (CAM), and the Profile of Mood States (POMS) questionnaire was applied to assess mood. The results were reported to the coaching staff, who made training adjustments according to the individual status of each athlete. Results: CK increased significantly from E1 to E2 (131.1 ± 80.9 vs 212.9 ± 131.7) and remained unchanged (212.9 ± 185.6) up to E3, while LDH was significantly reduced from E2 to E3 (590.7 ± 120.2 vs 457.8 ± 86.6), finishing the pre-competition training program with values similar to E1 (512.7 ± 190.6). The only change noted was the subjective sensation of fatigue from the POMS questionnaire that was significantly higher in E2 (4.82 ± 4.05) and E3 (5.5 ± 4.8) compared to E1 (2.06 ± 2.61), but no changes in total mood disturbance were detected in this instrument. Conclusion: With the modulation of training loads based on results of physiological tests, the members of the Brazilian national women's beach handball team responded in a physiologically adequate manner, even when faced with a sudden increase in training load for 18 consecutive days. Level of evidence III; Diagnostic study-investigation of a diagnostic test.

DIAGNOSIS OF OVERTRAINING SYNDROME

ABSTRACT Overtraining syndrome (OTS) is a condition associated with diminished sports performance due to an increase in the volume and/or intensity of physical activity without adequate rest, and/or due to an inadequate diet. The condition often involves hormonal, nutritional, emotional, muscle, immune and neurological imbalances. Epidemiology varies considerably, affecting both sexes in different age groups. Diagnosis is still a challenge, as the syndrome resembles different diseases. The lack of specific symptoms requires a meticulous investigation in all athletes, which is often multidisciplinary. OTS can have an important repercussion on sports performance and on the quality of life of athletes. Methods: This is a mapping of scientific literature along the lines of the Systemic Review. The databases investigated were: MEDLINE and Latin American and Caribbean Health Sciences Literature – LILACS and EMBASE, in addition to printed documents. Studies describing OTS were included, prioritizing articles that report the efficacy of the different diagnostic methods, be they clinical, laboratory, or imaging. Results: We found 83 articles, of which 30 were selected. Conclusion: The only symptom present in all the different forms of manifestation of OTS is loss of performance. However, some tests assessing oxidative stress levels seem promising, even though they are not specific. Revision article.

Heart Rate Monitoring in Team Sports-A Conceptual Framework for Contextualizing Heart Rate Measures for Training and Recovery Prescription

A comprehensive monitoring of fitness, fatigue, and performance is crucial for understanding an athlete's individual responses to training to optimize the scheduling of training and recovery strategies. Resting and exercise-related heart rate measures have received growing interest in recent decades and are considered potentially useful within multivariate response monitoring, as they provide non-invasive and time-efficient insights into the status of the autonomic nervous system (ANS) and aerobic fitness. In team sports, the practical implementation of athlete monitoring systems poses a particular challenge due to the complex and multidimensional structure of game demands and player and team performance, as well as logistic reasons, such as the typically large number of players and busy training and competition schedules. In this regard, exercise-related heart rate measures are likely the most applicable markers, as they can be routinely assessed during warm-ups using short (3–5 min) submaximal exercise protocols for an entire squad with common chest strap-based team monitoring devices. However, a comprehensive and meaningful monitoring of the training process requires the accurate separation of various types of responses, such as strain, recovery, and adaptation, which may all affect heart rate measures. Therefore, additional information on the training context (such as the training phase, training load, and intensity distribution) combined with multivariate analysis, which includes markers of (perceived) wellness and fatigue, should be considered when interpreting changes in heart rate indices. The aim of this article is to outline current limitations of heart rate monitoring, discuss methodological considerations of univariate and multivariate approaches, illustrate the influence of different analytical concepts on assessing meaningful changes in heart rate responses, and provide case examples for contextualizing heart rate measures using simple heuristics. To overcome current knowledge deficits and methodological inconsistencies, future investigations should systematically evaluate the validity and usefulness of the various approaches available to guide and improve the implementation of decision-support systems in (team) sports practice.

Bouts of exercise elicit discordant testosterone: cortisol ratios in runners and non-runners

OBJECTIVE

The testosterone:cortisol ratio (T:C) is suggested to be used in order to examine whether physical exercise generates either a "catabolic environment" or an "anabolic environment". The present study aims to evaluate the acute time-course profile of cortisol and testosterone due to an episode of physical exercise. A biphasic profile in the T:C ratio response was hypothesized.

MATERIALS AND METHODS

Morning sessions of treadmill running at two different intensities (Heart Rate at 65% and 80% of the maximum cardiac reserve) were performed by 6 male non-runners (NR) and 12 trained male runners (subdivided into trained runners T1 and T2). Cortisol and testosterone were measured in saliva. NR and T1 ran for 30 minutes at both intensities, and T2 ran for 46 minutes (± 4.1) at 65% and 42 minutes (± 3.5) at 80%.

RESULTS

In the 80% heart rate target, both groups of runners showed the biphasic time-profile, while the non-runners group did not. However, at the 65% level, none of the groups presented the hypothesized biphasic response.

CONCLUSIONS

A biphasic time-profile in the testosterone:cortisol ratio can be seen in short-bout, high intensity exercise (treadmill running) during the morning in men trained for this specific physical activity.

Excessive training induces molecular signs of pathologic cardiac hypertrophy

Chronic exercise induces cardiac remodeling that promotes left ventricular hypertrophy and cardiac functional improvement, which are mediated by the mammalian or the mechanistic target of rapamycin (mTOR) as well as by the androgen and glucocorticoid receptors (GRs). However, pathological conditions (i.e., chronic heart failure, hypertension, and aortic stenosis, etc.) also induce cardiac hypertrophy, but with detrimental function, high levels of proinflammatory cytokines and myostatin, elevated fibrosis, reduced adenosine monophosphate-activated protein kinase (AMPK) activation, and fetal gene reactivation. Furthermore, recent studies have evidenced that excessive training induced an inflammatory status in the serum, muscle, hypothalamus, and liver, suggesting a pathological condition that could also be detrimental to cardiac tissue. Here, we verified the effects of three running overtraining (OT) models on the molecular parameters related to physiological and pathological cardiac hypertrophy. C57BL/6 mice performed three different OT protocols and were evaluated for molecular parameters related to physiological and pathological cardiac hypertrophy, including immunoblotting, reverse transcription polymerase chain reaction, histology, and immunohistochemistry analyses. In summary, the three OT protocols induced left ventricle (LV) hypertrophy with signs of cardiac fibrosis and negative morphological adaptations. These maladaptations were accompanied by reductions in AMPKalpha (Thr172) phosphorylation, androgen receptor, and GR expressions, as well as by an increase in interleukin-6 expression. Specifically, the downhill running-based OT model reduced the content of some proteins related to the mTOR signaling pathway and upregulated the β-isoform of myosin heavy-chain gene expression, presenting signs of LV pathological hypertrophy development.

The neurobiological mechanisms of physical exercise in methamphetamine addiction

Methamphetamine (METH) is the primary drug within amphetamine-type stimulants which are the second most abused group of drugs worldwide. There is no pharmacological treatment addressed specifically to METH addiction, and behavioral therapy is shadowed by poor long-term recovery and relapse. Therefore, novel approaches to manage METH addiction are an urgent need. This review aims to describe the current state of physical exercise use on methamphetamine addiction management. The following searching terms in PubMed were used: ("physical exercise" OR "exercise") AND "methamphetamine." Relevant references from key publications and gray literature were also reviewed to identify additional citations for inclusion. Original investigation regarding physical exercise and methamphetamine addiction (clinical data) or neurobiological mechanisms of physical exercise in animal models of methamphetamine administration (preclinical data) was included. Overall, METH users demonstrated improvements, including better fitness and emotional measures, lower relapse rates, and sustained abstinence when compared to nonexercised individuals. The neurobiological mechanisms of physical exercise in METH users seem to reflect an interplay of several agents, including neurochemicals, oxidative stress, neurogenesis, gliogenesis, and blood-brain barrier as disclosed by preclinical data. Exercise-based interventions alone or as a conjoint therapy may be a useful tool for managing METH addiction.

Treadmill Slope Modulates Inflammation, Fiber Type Composition, Androgen, and Glucocorticoid Receptors in the Skeletal Muscle of Overtrained Mice

Overtraining (OT) may be defined as an imbalance between excessive training and adequate recovery period. Recently, a downhill running-based overtraining (OTR/down) protocol induced the nonfunctional overreaching state, which is defined as a performance decrement that may be associated with psychological and hormonal disruptions and promoted intramuscular and systemic inflammation. To discriminate the eccentric contraction effects on interleukin 1beta (IL-1β), IL-6, IL-10, IL-15, and SOCS-3, we compared the release of these cytokines in OTR/down with other two OT protocols with the same external load (i.e., the product between training intensity and volume), but performed in uphill (OTR/up) and without inclination (OTR). Also, we evaluated the effects of these OT models on the muscle morphology and fiber type composition, serum levels of fatigue markers and corticosterone, as well as androgen receptor (AR) and glucocorticoid receptor (GR) expressions. For extensor digitorum longus (EDL), OTR/down and OTR groups increased the cytokines and exhibited micro-injuries with polymorphonuclear infiltration. While OTR/down group increased the cytokines in soleus muscle, OTR/up group only increased IL-6. All OT groups presented micro-injuries with polymorphonuclear infiltration. In serum, while OTR/down and OTR/up protocols increased IL-1β, IL-6, and tumor necrosis factor alpha, OTR group increased IL-1β, IL-6, IL-15, and corticosterone. The type II fibers in EDL and soleus, total and phosphorylated AR levels in soleus, and total GR levels in EDL and soleus were differentially modulated by the OT protocols. In summary, the proinflammatory cytokines were more sensitive for OTR/down than for OTR/up and OTR. Also, the specific treadmill inclination of each OT model influenced most of the other evaluated parameters.