Recommendations to maintain immune health in athletes

Immunity, Inflammation and Airway Dysfunction in Elite Cross-Country Skiers and Ice Hockey Players: A Systematic Review

Strenuous exercise in elite sports impacts the immune system, leading to high rates of upper respiratory tract infections and airway dysfunction, such as asthma and exercise-induced bronchoconstriction (EIB). Cross-country (XC) skiers and ice hockey (IH) players are particularly affected due to their training environments and sports disciplines. This systematic review (SR) evaluates immune and inflammatory responses and the risk of developing airway dysfunction in these athletes. Original articles focusing on immune response, systemic inflammation, and airway dysfunction in competitive XC skiers and IH players were retrieved from MEDLINE/Ovid, EMBASE, and the Cochrane Library. Risk of bias was assessed using the Cochrane Risk of Bias Tool. Of 3582 studies screened, 50 met the inclusion criteria. Both elite XC skiers and IH players exhibit increased cortisol levels and altered systemic immune cell compositions in response to training and competition. Both groups show neutrophilic or mixed neutrophilic/eosinophilic airway inflammation, in contrast to the primarily eosinophilic inflammation associated with allergic asthma. Both XC skiers (27%) and IH players (14%) had a high prevalence of physician-diagnosed asthma. This SR highlights the notable burden of airway dysfunction in elite winter athletes, with elevated rates of asthma and EIB. The observed inflammatory patterns support the concept of a "sport asthma" endotype, which may be a result of chronic exposure to cold, dry air. Effective management may benefit from refined diagnostic criteria, the identification of specific biomarkers, and tailored prevention and treatment strategies for asthma and EIB.

Why Is the Association Between Mediterranean Diet and Physical Performance in Athletes Inconclusive? Implications for Future Studies

Background/Objectives: Athletes increasingly turn to nutrition and supplements to enhance performance, yet the evidence surrounding the efficacy of the Mediterranean diet (MD) remains inconclusive. This scoping review aims to evaluate identify gaps in the existing literature and provide implications for future research on the MD's potential to improve athletic performance across various demographics, sport types, and performance measures. Methods: We conducted a systematic search of peer-reviewed studies published across four databases (PubMed, Scopus, Scielo, and Google Scholar) using the following terms and their combinations: "mediterranean diet", "performance", "athlete", "sport". The search placed no restrictions on the experimental design or the time period of the publication and focused on athletes regardless of competitive level. We examined targeted studies about the MD's effects on key performance metrics, such as endurance, strength, and speed, while also evaluating possible confounding factors like dietary intake, body composition, and training status. We further aimed to identify gaps in the literature by investigating the consistency of dosing protocols, supplementation duration, and methodologies used. Results: The preliminary findings suggest that while some studies report benefits of the MD for recovery and endurance, only 40% show statistically significant improvements in performance outcomes, often with methodological limitations. The studies also lacked homogeneity in participant demographics, dosage, and performance assessments, hindering comparability. Our review highlights the need for future research that incorporates standardized dosing, homogeneous athlete populations, and controlled dietary conditions. Conclusions: This review provides a framework to guide further research and offers insights into the potential role of the MD in sports nutrition.

Respiratory problems in rowers: outcomes from a systematic assessment of an elite squad

OBJECTIVES

To characterise the respiratory health of elite rowers using a systematic screening approach to assess respiratory health (SARAH) and identify the associations between SARAH findings and acute respiratory illness (ARI) and chest wall injury (CWI).

METHODS

A systematic screening approach was conducted in a cohort of elite rowers. The assessment employed validated respiratory questionnaires and multiple physiological measures. An analysis of ARI and CWI incidence and burden from the 18 months before the SARAH assessment was conducted.

RESULTS

Full respiratory surveillance was completed in 48 rowers (50% female, aged 27 [25-28] years). The incidence and burden of ARI were similar between male and female rowers. The incidence of CWI was greater in female rowers compared to males (1.6 versus 0.4 per 1000 athlete training days, respectively; incidence rate ratio of 4.3, 95% C.I. 1.5 to 12.2, p=0.005) and more common in younger rowers with greater lung function. SARAH detected at least one respiratory problem in 39 (81%) rowers, and two or more problems in 26 (54%). Sino-nasal problems (44%), allergy-related problems (42%) and breathing pattern disorder (42%) were the most prevalent problems identified. Exercise-associated cough was reported in 34 (71%) rowers, with objective evidence of asthma found in only five (10%).

CONCLUSIONS

In elite rowers, respiratory problems, including ARI and CWI, are common and impact health. A systematic screening approach identifies multiple underlying respiratory problems, presenting the opportunity to optimise athlete health and improve training availability.

Does Relative Energy Deficiency in Sport (REDs) Syndrome Exist?

Relative energy deficiency in sport (REDs) is a widely adopted model, originally proposed by an International Olympic Committee (IOC) expert panel in 2014 and recently updated in an IOC 2023 consensus statement. The model describes how low energy availability (LEA) causes a wide range of deleterious health and performance outcomes in athletes. With increasing frequency, sports practitioners are diagnosing athletes with "REDs," or "REDs syndrome," based largely upon symptom presentation. The purpose of this review is not to "debunk" REDs but to challenge dogmas and encourage rigorous scientific processes. We critically discuss the REDs concept and existing empirical evidence available to support the model. The consensus (IOC 2023) is that energy availability, which is at the core of REDs syndrome, is impossible to measure accurately enough in the field, and therefore, the only way to diagnose an athlete with REDs appears to be by studying symptom presentation and risk factors. However, the symptoms are rather generic, and the causes likely multifactorial. Here we discuss that (1) it is very difficult to isolate the effects of LEA from other potential causes of the same symptoms (in the laboratory but even more so in the field); (2) the model is grounded in the idea that one factor causes symptoms rather than a combination of factors adding up to the etiology. For example, the model does not allow for high allostatic load (psychophysiological "wear and tear") to explain the symptoms; (3) the REDs diagnosis is by definition biased because one is trying to prove that the correct diagnosis is REDs, by excluding other potential causes (referred to as differential diagnosis, although a differential diagnosis is supposed to find the cause, not demonstrate that it is a pre-determined cause); (4) observational/cross-sectional studies have typically been short duration (< 7 days) and do not address the long term "problematic LEA," as described in the IOC 2023 consensus statement; and (5) the evidence is not as convincing as it is sometimes believed to be (i.e., many practitioners believe REDs is well established). Very few studies can demonstrate causality between LEA and symptoms, most studies demonstrate associations and there is a worrying number of (narrative) reviews on the topic, relative to original research. Here we suggest that the athlete is best served by an unbiased approach that places health at the center, leaving open all possible explanations for the presented symptoms. Practitioners could use a checklist that addresses eight categories of potential causes and involve the relevant experts if and when needed. The Athlete Health and Readiness Checklist (AHaRC) we introduce here simply consists of tools that have already been developed by various expert/consensus statements to monitor and troubleshoot aspects of athlete health and performance issues. Isolating the purported effects of LEA from the myriad of other potential causes of REDs symptoms is experimentally challenging. This renders the REDs model somewhat immune to falsification and we may never definitively answer the question, "does REDs syndrome exist?" From a practical point of view, it is not necessary to isolate LEA as a cause because all potential areas of health and performance improvement should be identified and tackled.

The effect of 12-week high-dose Colostrum Bovinum supplementation on immunological, hematological and biochemical markers in endurance athletes: a randomized crossover placebo-controlled study

Background

Bovine colostrum (COL) is assumed to be one of the strongest natural immune stimulants. Regular ingestion of COL may contribute to improved immune response in athletes exposed to high training loads.

Methods

Twenty-eight endurance-trained males aged 31.1 ± 10.2 years (body mass 81.9 ± 9.0 kg; height 1.82 ± 0.06 m) completed this randomized double-blind placebo(PLA)-controlled crossover study aimed at investigating the effect of 12-week COL supplementation (25gCOL·day-1) on resting (REST), exercise-induced (POST-EX), and short-term post-exercise recovery (REC; 1 h after test exercise) changes in selected saliva and blood immunoglobulins (Ig), white blood cell (WBC) count and differential; as well as blood hematological, nutritional status and muscle damage indices. The protocol assumed 4 study visits - before/after supplementation with COL (COLPRE and COLPOST ) and PLA (PLAPRE and PLAPOST ). During testing sessions, incremental rowing test to exhaustion and swimming-specific performance test were introduced as exercise stimuli.

Results

At COLPOST visit the secretory IgA (SIgA) concentration in saliva was significantly higher at POST-EX and REC compared to REST (p<0.05). COL supplementation had no effect on blood IgA, IgE, IgD, IgG, and IgM concentrations. Furthermore, after COL supplementation decrease of hematocrit at REC (p<0.05) was revealed.

Conclusions

12-week supplementation with 25 gCOL·day-1 in endurance-trained male athletes resulted in a favorable increase in post-exercise concentration of salivary SIgA. COL seems to be a potential stimulator of local immune defense after exercise-induced homeostasis disturbances. Nevertheless, the lack of effect on blood markers indicates the need for further research in the area of mechanisms underlying the effect of the supposed COL immunological capacity.

'Supporting the Support Staff': A Narrative Review of Nutritional Opportunities to Enhance Recovery and Wellbeing in Multi-Disciplinary Soccer Performance Staff

BACKGROUND

With ever-increasing training, match-play and travel demands in professional soccer, recovery is vital for athletic performance, a statement amplified in tournament and in-season scenarios. However, alongside supporting the tasks associated with these increased demands, the recovery and wellbeing strategies recommended for playing staff are often unavailable to their support staff counterparts, who routinely experience extended working hours over and above scheduled player attendance.

METHODS

Focusing on the contributions of nutrition to this undoubtedly multifactorial issue, this narrative review aimed to (1) identify potential strategies to enhance recovery and wellbeing in multi-disciplinary soccer support staff and (2) highlight future research opportunities exploring the benefits of nutrition for those staff in soccer performance-related support roles.

RESULTS

The potential health and wellbeing consequences of chronic sub-optimal practices suggest that chrononutrition strategies may be an area of future interest. Notably, nutritional strategies that enhance sleep hygiene and immune function warrant consideration. Individualizing such strategies to maximize recovery and wellbeing in multi-disciplinary soccer support staff should offer an adjunct and complementary strategy to the holistic performance-focused support provided to professional soccer players.

CONCLUSIONS

Policymakers responsible for organizational and club structures aligned with soccer performance could consider 'Supporting the Support Staff' when seeking to improve overall performance.

Acute Inflammatory Response to Eccentric Exercise in Young and Master Resistance-trained Athletes

This study aimed to compare the acute inflammatory response following high-intensity eccentric exercise between resistance-trained young and master athletes with similar performance levels. Resistance-trained young (n=8; 22±2 years) and master (n=8; 52±4 years) male athletes of a similar performance level performed a standardized high-intensity eccentric squat exercise protocol (10 sets of half-squats at 70% of 1-repetition maximum). The serum concentration of 20 biomarkers related to tissue damage, inflammation, remodeling, and repair was measured at baseline, immediately after exercise, and over a 72 h recovery period. Both groups experienced similar muscle damage as evidenced by a comparable increase in creatine kinase activity 24 h after exercise (p<0.001). Interleukin-6 (p=0.009) and growth hormone (p<0.001) increased immediately post-exercise in both groups. Monocyte chemoattractant protein-1 increased immediately post-exercise only in young athletes (p=0.003) and then decreased 24 h later. There were no significant differences for the remaining variables, including cell markers related to neutrophil/macrophage activation or pro/anti-inflammatory cytokines. Resistance-trained young and master athletes, matched for performance level, showed an overall similar inflammatory response to eccentric exercise, possibly reflecting regulatory mechanisms or immunological adaptations to chronic stimulation in master athletes.

Beyond Menstrual Dysfunction: Does Altered Endocrine Function Caused by Problematic Low Energy Availability Impair Health and Sports Performance in Female Athletes?

Low energy availability, particularly when problematic (i.e., prolonged and/or severe), has numerous negative consequences for health and sports performance as characterized in relative energy deficiency in sport. These consequences may be driven by disturbances in endocrine function, although scientific evidence clearly linking endocrine dysfunction to decreased sports performance and blunted or diminished training adaptations is limited. We describe how low energy availability-induced changes in sex hormones manifest as menstrual dysfunction and accompanying hormonal dysfunction in other endocrine axes that lead to adverse health outcomes, including negative bone health, impaired metabolic activity, undesired outcomes for body composition, altered immune response, problematic cardiovascular outcomes, iron deficiency, as well as impaired endurance performance and force production, all of which ultimately may influence athlete health and performance. Where identifiable menstrual dysfunction indicates hypothalamic-pituitary-ovarian axis dysfunction, concomitant disturbances in other hormonal axes and their impact on the athlete's health and sports performance must be recognized as well. Given that the margin between podium positions and "losing" in competitive sports can be very small, several important questions regarding low energy availability, endocrinology, and the mechanisms behind impaired training adaptations and sports performance have yet to be explored.

1-Year Prevalence and Factors Related to Injuries and Illnesses in Japanese Judo Collegiate Athletes

Despite its rich history and widespread participation, the research surrounding injuries and illness in judo remains relatively limited compared to other sports. The primary aim of this research was to investigate injuries and illness within a previous year in Japanese collegiate judo athletes and analyze possible factors associated with these. This was a cross-sectional observational study using a web-based survey to collect data on the 1-year prevalence of injuries and illness. This study involved 564 judo athletes (67% males), aged between 18 and 25 years. Of these, 344 athletes (61%) reported one or more injuries within the previous year, and 49 reported illness (9%). The more judo experiences the athlete acquired, the less likely they were to sustain an injury (OR: 0.9; 95% CI: 0.56-1.10; p-value < 0.05) or illness (OR: 0.9; 95% CI: 0.81-1.00; p-value < 0.05). Support of an athletic trainer was associated with 1.7 times increased odds of sustaining an injury (95% CI: 1.19-2.49; p-value < 0.05). Athletes with obese BMI status (BMI > 30) had 3.1 times higher odds of becoming ill (95% CI: 1.41-6.95; p-value = 0.005), and athletes training more than 5 days per week had the odds of becoming ill increased by 5.1 times (95% CI: 1.11-23.21; p-value = 0.036). Judokas with fewer years of experience and with obese status should be targeted in efforts to prevent injury and illness. Moreover, the support of an athletic trainer and the impact of weekly training days should be targeted in research efforts.

Sports and Immunity, from the recreational to the elite athlete

The pivotal role of the immune system in physical activity is well-established. While interactions are complex, they tend to constitute discrete immune responses. Moderate intensity exercise causes leukocytosis with a mild anti-inflammatory cytokine profile and immunoenhancement. Above a threshold of intensity, lactate-mediated IL-6 release causes a proinflammatory state followed by a depressed inflammatory state, which stimulates immune adaptation and longer term cardiometabolic enhancement. Exercise-related immune responses are modulated by sex, age and immunonutrition. At all ability levels, these factors collectively affect the immune balance between enhancement or overload and dysfunction. Excessive training, mental stress or insufficient recovery risks immune cell exhaustion and hypothalamic pituitary axis (HPA) stress responses causing immunodepression with negative impacts on performance or general health. Participation in sport provides additional immune benefits in terms of ensuring regularity, social inclusion, mental well-being and healthier life choices in terms of diet and reduced smoking and alcohol, thereby consolidating healthy lifestyles and longer term health. Significant differences exist between recreational and professional athletes in terms of inherent characteristics, training resilience and additional stresses arising from competition schedules, travel-related infections and stress. Exercise immunology examines the central role of immunity in exercise physiology and straddles multiple disciplines ranging from neuroendocrinology to nutrition and genetics, with the aim of guiding athletes to train optimally and safely. This review provides a brief outline of the main interactions of immunity and exercise, some influencing factors, and current guidance on maintaining immune health.

Immune consequences of exercise in hypoxia: A narrative review

Immune outcomes are key mediators of many health benefits of exercise and are determined by exercise type, dose (frequency/duration, intensity), and individual characteristics. Similarly, reduced availability of ambient oxygen (hypoxia) modulates immune functions depending on the hypoxic dose and the individual capacity to respond to hypoxia. How combined exercise and hypoxia (e.g., high-altitude training) sculpts immune responses is not well understood, although such combinations are becoming increasingly popular. Therefore, in this paper, we summarize the impact on immune responses of exercise and of hypoxia, both independently and together, with a focus on specialized cells in the innate and adaptive immune system. We review the regulation of the immune system by tissue oxygen levels and the overlapping and distinct immune responses related to exercise and hypoxia, then we discuss how they may be modulated by nutritional strategies. Mitochondrial, antioxidant, and anti-inflammatory mechanisms underlie many of the adaptations that can lead to improved cellular metabolism, resilience, and overall immune functions by regulating the survival, differentiation, activation, and migration of immune cells. This review shows that exercise and hypoxia can impair or complement/synergize with each other while regulating immune system functions. Appropriate acclimatization, training, and nutritional strategies can be used to avoid risks and tap into the synergistic potentials of the poorly studied immune consequences of exercising in a hypoxic state.

Dietary Intake of Soccer Players before, during and after an Official Game: Influence of Competition Level and Playing Position

Physical demands in soccer differ according to league level and playing position and may influence nutritional requirements. This study examined the effect of competition level and playing position on dietary intake in male soccer players (SP). Diet was weighed and recorded by 123 SP for 3 days; before, on the day, and the day after an official match. SP in the Super League (SL, n = 33) division reported higher (p < 0.05) average three-day energy (195 ± 36 kJ/kg), carbohydrate (6.0 ± 1.1 g/kg), and protein (2.2 ± 0.5 g/kg) intakes compared to the intakes reported by SP in the 2nd (n = 30) (energy: 159 ± 31 kJ/kg; carbohydrate: 4.6 ± 1.2 g/kg; protein: 1.9 ± 0.4 g/kg), 3rd (n = 30) (energy: 153 ± 34 kJ/kg; carbohydrate: 4.5 ± 1.2 g/kg; protein: 1.7 ± 0.4 g/kg), and 4th (n = 30) (energy: 152 ± 36 kJ/kg; carbohydrate: 4.2 ± 1.2 g/kg; protein: 1.7 ± 0.5 g/kg) national leagues (mean ± SD). Furthermore, when data were analyzed by playing position (pooled data), wide midfielders reported higher (p < 0.05) energy (183 ± 33 kJ/kg), carbohydrate (5.4 ± 1.2 g/kg), and fat (1.5 ± 0.4 g/kg) intakes compared to central defenders (energy: 147 ± 37 kJ/kg; carbohydrate: 4.1 ± 1.1 g/kg; fat: 1.2 ± 0.4 g/kg). The dietary intake of SP may differ according to the playing position and competition level, possibly due to different metabolic demands in training and competition.

Effects of plank exercise on respiratory capacity, physical fitness, and immunocytes in older adults

Plank is a readily accessible form of exercise that can benefit individuals of various fitness levels. However, its effectiveness in older individuals has not been conclusively established. Specifically, its impact on respiratory function, physical fitness, and immunocytes in them has not been thoroughly verified. The study encompassed participants with an average age of 64.33±1.98 years. All participants were randomly assigned to either the control group (COG) or the plank exercise group (PXG). The plank exercise was conducted 3 days a week for 12 weeks. While the values in the COG deteriorated, the PXG showed significant improvements in several parameters. Forced expiratory volume in one second and peak expiratory flow increased by approximately 27% and 16%, respectively, in the PXG, demonstrating significant differences (P<0.001) between the two groups. Additionally, VO2max, grip strength, and sit-ups increased by about 12%, 18%, and 42% in the PXG. Notably, innate immunocytes, such as NK cells, increased by approximately 30% in the PXG. For adaptive immunocytes, including CD3+ T cells, CD4+ T cells, and CD8+ T cells, there were notable increases of around 18%, 19%, and 28%, respectively, in the PXG. These findings underline significant differences (P<0.001) between the two groups. This study provides confirmation that engaging in plank exercise can enhance the function of immunocytes, while also improving respiratory capacity and physical fitness in older adults.

Considerations for the Consumption of Vitamin and Mineral Supplements in Athlete Populations

Vitamins and minerals are of fundamental importance to numerous human functions that are essential to optimise athlete performance. Athletes incur a high turnover of key vitamins and minerals and are therefore dependent on sufficient energy intake to replenish nutrient stores. However, many athletes are poor at servicing their energy replenishment needs, especially female athletes, and although a 'food first approach' to meeting nutrient requirements is the primary goal, it may be important for some athletes to consider a vitamin and/or mineral supplement to meet their daily needs. When working to determine if an athlete requires vitamin or mineral supplements, practitioners should use a robust framework to assess the overall energy requirements, current dietary practices and the biological and clinical status of their athletes. Of note, any supplementation plan should account for the various factors that may impact the efficacy of the approach (e.g. athlete sex, the nutrient recommended dietary intake, supplement dose/timing, co-consumption of other foods and any food-drug interactions). Importantly, there are numerous vitamins and minerals of key importance to athletes, each having specific relevance to certain situations (e.g. iron and B vitamins are significant contributors to haematological adaptation, calcium and vitamin D are important to bone health and folate is important in the female athlete); therefore, the appropriate supplement for a given situation should be carefully considered and consumed with the goal to augment an athlete's diet.

A Pilot Study of the Biofeedback Training to Reduce Salivary Cortisol Level and Improve Mental Health in Highly-Trained Female Athletes

Biofeedback (BFB) training can provide a useful resource for athletes to cope with stress. However, the effects of BFB training on acute and chronic endocrine stress responses, parasympathetic activity, and mental health in competitive athletes have not been explored yet. This pilot study examined the effects of a 7-week BFB training on psychophysiological parameters in highly trained female athletes. Six highly trained female volleyball players (mean age: 17.50 ± 1.05 years) volunteered to participate in the study. Athletes individually attended 21-session heart rate variability (HRV)-BFB training consisting of six minutes for 7 weeks. A BFB device (Nexus 10) was used to measure the athletes' physiological responses reflecting HRV. To assess the cortisol awakening response (CAR), saliva samples were collected immediately after awakening and 15 min, 30 min, and 60 min post-awakening. The Depression Anxiety Stress Scale-21 was filled out before and after the intervention to assess mental health. Furthermore, athletes provided saliva samples during eight sessions pre- and immediately post-session. Mid-day cortisol levels decreased significantly after the intervention. No significant change was observed in CAR and physiological responses after the intervention. A significant decrease in cortisol level was observed in BFB sessions in which cortisol level was assessed, except for two sessions. We concluded that short sessions of 7-week HRV-BFB training could be used as an effective method to control autonomic functions and stress of female athletes. Although the present study provides strong evidence for the psychophysiological well-being of athletes, further investigations with larger samples are needed.

Impact of COVID-19 outbreak on the mental health in sports: a review

Global pandemic, lockdown restrictions, and COVID-19 compulsory social isolation guidelines have raised unprecedented mental health in the sports community. The COVID-19 pandemic is found to affect the mental health of the population. In critical situations, health authorities and sports communities must identify their priorities and make plans to maintain athletes' health and athletic activities. Several aspects play an important role in prioritization and strategic planning, e.g., physical and mental health, distribution of resources, and short to long-term environmental considerations. To identify the psychological health of sportspeople and athletes due to the outbreak of COVID-19 has been reviewed in this research. This review article also analyzes the impact of COVID-19 on health mental in databases. The COVID-19 outbreak and quarantine would have a serious negative impact on the mental health of athletes. From the accessible sources, 80 research articles were selected and examined for this purpose such as Research Gate, PubMed, Google Scholar, Springer, Scopus, and Web of Science and based on the involvement for this study 14 research articles were accessed. This research has an intention on mental health issues in athletes due to the Pandemic. This report outlines the mental, emotional and behavioural consequences of COVID-19 home confinement. Further, research literature reported that due to the lack of required training, physical activity, practice sessions, and collaboration with teammates and coaching staff are the prime causes of mental health issues in athletes. The discussions also reviewed several pieces of literature which examined the impacts on sports and athletes, impacts on various countries, fundamental issues of mental health and the diagnosis for the sports person and athletes, and the afterlife of the COVID-19 pandemic for them. Because of the compulsory restrictions and guidelines of this COVID-19 eruption, the athletes of different sports and geographical regions are suffering from fewer psychological issues which were identified in this paper. Accordingly, the COVID-19 pandemic appears to negatively affect the mental health of the athletes with the prevalence and levels of anxiety and stress increasing, and depression symptoms remaining unaltered. Addressing and mitigating the negative effect of COVID-19 on the mental health of this population identified from this review.

The effects of a single and a series of Finnish sauna sessions on the immune response and HSP-70 levels in trained and untrained men

BACKGROUND

The aim of the study was to investigate the effect of a Finnish sauna on the immune status parameters. The hypothesis was that hyperthermia would improve immune system's functioning by changing the proportion of lymphocyte subpopulations and would activate heat shock proteins. We assumed that the responses of trained and untrained subjects would be different.

MATERIAL AND METHODS

Healthy men (20-25 years old) were divided into groups: the trained (T; n = 10), and the untrained group (U; n = 10). All participants were subjected to 10 baths (each one consisted of: 3 × 15-minute exposure with cooled down for 2 min. Body composition, anthropometric measurements, VO₂ peak were measured before 1st sauna bath. Blood was collected before the 1st and 10th sauna bath, and 10 min after their completion to asses an acute and a chronic effect. Body mass, rectal temperature and heart rate (HR) were assessed in the same time points. The serum levels of cortisol, Il-6, HSP70 were measured with use of ELISA method, IgA, IgG and IgM by turbidimetry. White blood cells (WBC), leukocyte populations counts: neutrophils, lymphocytes, eosinophils, monocytes, and basophils were determined with use of flow cytometry as well as T-cell subpopulations.

RESULTS

No differences were found in the increase in rectal temperature, cortisol and immunoglobulins between groups. In response to the 1st sauna bath, a greater increase in HR was observed in the U group. After the last one, the HR value was lower in the T group. The impact of sauna baths on WBC, CD56+, CD3+, CD8+, IgA, IgG and IgM was different in trained and untrained subjects' responses. A positive correlation between the increase in cortisol concentrations and increase in internal temperatures after the 1st sauna was found in the T (r = 0.72) and U group (r = 0.77), between the increase in IL-6 and cortisol concentrations in the T group after the 1st treatment (r = 0.64), between the increase in IL-10 concentration and internal temperature (r = 0.75) and between the increase in IL-6 and IL-10 (r = 0.69) concentrations, also.

CONCLUSIONS

Sauna bathing can be a way to improve the immune response, but only when it is undertaken as a series of treatments.

Comparison of the Effects of Prebiotics and Synbiotics Supplementation on the Immune Function of Male University Football Players

This study was conducted to compare the effects of long-term prebiotic and synbiotic supplementations on the immunosuppression of male football players after daily high-intensity training and a one-time strenuous exercise. A total of 30 male university student-athletes were recruited and randomly assigned to the prebiotic (PG, n = 15) or synbiotic group (SG, n = 15), receiving a prebiotic or synbiotic once per day for six weeks. Physiological assessments were conducted by a maximal oxygen uptake (VO2max) test and an exhaustive constant load exercise (75% VO2max test). Inflammatory cytokine and secretory immunoglobulin A (SIgA) were measured. VO2max, maximal heart rate (HRmax), and lactic acid elimination rate (ER) were used to evaluate aerobic capacity. Upper respiratory tract infection (URTI) complaints were evaluated using a questionnaire. URTI incidence and duration were significantly lower in the SG group than that in the PG group (p < 0.05). At baseline, SIgA and interleukin-1β (IL-1β) levels in the SG group (p < 0.01) as well as IL-1β and IL-6 in the PG group (p < 0.05) were significantly increased, and IL-4 concentration was markedly reduced in the PG group (p < 0.01). The concentrations of IL-4, IL-10 and transforming growth factor-β1 (TGF-β1) were significantly reduced in the PG and SG group immediately after the constant load exercise. Significantly decreased HRmax and enhanced ER (increased by 193.78%) were detected in the SG group, not in the PG group, during the constant load experiment (p < 0.05) and the recovery period (p < 0.01), respectively. However, VO2max value was not changed. These data suggest that synbiotic supplementation for six weeks has a more positive effect than prebiotics on the immune function and athletic performance of male university football players.

The Sleep Parameters of Paralympic Athletes: Characteristics and Assessment Instruments

CONTEXT

Sleep serves many important functions for athletes, particularly in the processes of learning, memory, recovery, and cognition.

OBJECTIVES

Define the sleep parameters of Paralympic athletes and identify the instruments used to assess and monitor sleep Paralympic athletes.

EVIDENCE ACQUISITION

This systematic review was carried out based on the PRISMA guidelines. The survey was conducted in April 2020, the searches were carried out again in September 2021 to check whether there were new scientific publications in the area of sleep and Paralympic sport, searches were performed in the following databases: PubMed, Web of Science, Scopus, SPORTDiscus, Virtual Health Library (BIREME), and SciELO. This systematic review has included studies that investigated at least one of the following sleep parameters: total sleep time, sleep latency, sleep efficiency, number of awakenings, quality of sleep, daytime sleepiness, and chronotype; the participants were comprised of athletes with disabilities. Studies published at any time in English, Portuguese, and Spanish, were included.

EVIDENCE SYNTHESIS

Data extraction and study selection were performed by 2 researchers independently, and a third author was consulted as necessary. The search returned a total of 407 studies. Following the screening based on exclusion and inclusion criteria, a total of 13 studies were considered. Paralympic athletes have a low amount (7.06 h) of sleep with poor quality and sleep latency (28.05 min), and 57.2% have daytime sleepiness, with the majority belonging to the indifferent chronotype (53, 5%). Moreover, 11 studies assess sleep using subjective instruments (questionnaires), and 2 studies used an objective instrument (actigraphy).

CONCLUSIONS

Sleep disorders are common among Paralympic athletes, poor sleep quality and quantity, and high rates of daytime sleepiness. Subjective methods are most commonly used to assess sleep.

Antioxidant, anti-inflammatory and immunomodulatory effects of spirulina in exercise and sport: A systematic review

Arthrospira platensis, also known as spirulina, is currently one of the most well-known algae supplements, mainly due to its high content of bioactive compounds that may promote human health. Some authors have hypothesized that spirulina consumption could protect subjects from exercise-induced oxidative stress, accelerate recovery by reducing muscle damage, and stimulate the immune system. Based on this, the main goal of this review was to critically analyze the effects of spirulina on oxidative stress, immune system, inflammation and performance in athletes and people undergoing exercise interventions. Of the 981 articles found, 428 studies were considered eligible and 13 met the established criteria and were included in this systematic review. Most recently spirulina supplementation has demonstrated ergogenic potential during submaximal exercise, increasing oxygen uptake and improving exercise tolerance. Nevertheless, spirulina supplementation does not seem to enhance physical performance in power athletes. Considering that data supporting benefits to the immune system from spirulina supplementation is still lacking, overall evidence regarding the benefit of spirulina supplementation in healthy people engaged in physical exercise is scarce and not consistent. Currently, spirulina supplementation might be considered in athletes who do not meet the recommended dietary intake of antioxidants. Further high-quality research is needed to evaluate the effects of spirulina consumption on performance, the immune system and recovery in athletes and active people.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=262896], identifier [CRD42021262896].

Psychological and physiological changes during basic, underwater, demolition/SEAL training

This longitudinal study examines the growth of psychological characteristics and adaptation of physiological markers of stress during a six-month assessment and selection course for U.S. Navy SEALs. Resilience, hardiness, and grit instruments were used to evaluate the psychological characteristics. Blood samples were taken to determine physiological markers related to stress adaptation; specifically, evaluating DHEA, DHEA-to-cortisol ratio, BDNF, NPY, and cortisol. Data was collected at four timepoints throughout the assessment and selection course from 353 students over three classes. Results indicated that resilience and hardiness grow after an initial decline, DHEA and DHEA-to-cortisol increased suggesting physiological adaptation. However, psychological and physiological markers do not exhibit the same growth patterns for participants in the course. This study enhances the understanding of psychological growth and physiological adaptation in a high-stress environment over an extended duration.

Nutritional Practices and Body Composition of South African National-Level Spinal Cord-Injured Endurance Hand Cyclists

Nutritional practices and body composition of para-athletes can impact their health and athletic performance. There is a paucity of research on the nutritional practices, including dietary and supplement intake, body composition and bone health of spinal cord-injured (SCI) endurance hand cyclists. This study assessed the body composition and dietary and supplement intake of 12 national-level SCI endurance hand cyclists (age: 44.0 ± 9.3 years). Bone mineral density (BMD) was assessed in a sub-sample of participants (n = 4) using dual-energy x-ray absorptiometry (DXA). Estimated body fat percentage was healthy (18.4 ± 5.1%) and lumbar spine BMD for the sub-sample was adequate, however hip BMD was low (Z-score and/or T-scores < −2). Carbohydrate intake for male and female participants was below the recommended intake (3.8 (2.9−4.1) and 2.4 (2.0−2.7) g/kg BW, respectively). Overall protein intake was adequate, whilst fat intake was high for both males and females (39.7 (37.7−41.6) and 42.1 (39.0−45.3)% of total energy, respectively). The reported intakes for a few key micronutrients were also below the recommended dietary allowance (RDA) and/or adequate intake (AI) for males (vitamin D, calcium). The prevalence of supplement use before, during, and after training was 40%, 100%, and 60%, respectively. In conclusion, the hand cyclists could benefit from nutritional guidance to match their daily carbohydrate intake with exercise requirements and optimise their fat intake. Optimal vitamin D and calcium intake is also important especially in the light of poor bone health below the lesion level.

Effects of caffeinated beverage ingestion on salivary antimicrobial proteins responses to acute exercise in the heat

Caffeine is commonly used by athletes as an energy supplement, but studies on its effects on salivary antimicrobial proteins (sAMPs) in humans during exercise are rare with ambiguous findings. It is also still controversial whether hot environments affect sAMPs. Using a double-blind, randomized crossover design, we examined 12 endurance-trained male collegiate athletes who completed the following two experiments: a caffeine experiment (CAF) and a placebo experiment (PLA). The participants acutely consumed caffeine-containing (6 mg/kg body weight) sports drink (3 ml/kg body weight) or an equivalent amount of placebo sports drink and subsequently performed cycling exercise for 40 min in the heat (33 ± 0.24°C, 64 ± 2.50% relative humidity) at 50% of maximum output power, maintaining a pedal frequency of 60 rpm. Saliva was collected at 60 min pre-exercise (T–60), the start of exercise (T0), 20 min of exercise (T20), and the end of the exercise (T40), and salivary α-amylase (sAA) and lactoferrin (sLac) were tested. The rating of perceived exertion (RPE) was measured at T0–T40, while core body temperature (Tre) and heart rate (HR) were monitored continuously. Tre, HR, and RPE increased with time during the exercise (p &lt; 0.01), with no difference in Tre and HR between the CAF and PLA (p &gt; 0.05), but RPE was higher in the PLA than in the CAF (p &lt; 0.05). sLac concentrations were significantly higher at T20 and T40 than at T–60 (p &lt; 0.01) and higher at T40 than at T0 and T20 (p &lt; 0.01), with no difference between the CAF and PLA (p &gt; 0.05). Compared with T–60, sAA activity was significantly increased at T0, T20, and T40 (p &lt; 0.01). sAA activity was significantly higher at T40 than at T0 and T20 (p &lt; 0.01), at T20 than at T0 (p &lt; 0.05), and in the CAF than in the PLA (p &lt; 0.01). Heat stress caused by acute exercise in hot environments did not impair the sAMPs parameters of the participants. Instead, the participants showed transient increase in sAA activity and unchanged sLac concentrations. Caffeine may increase salivary markers related to immune response during exercise.

Associations between cardiorespiratory fitness, monocyte polarization, and exercise-related changes in mnemonic discrimination performance in older adults

Biological aging is accompanied by a chronic pro-inflammatory state that may facilitate losses in hippocampal-dependent mnemonic discrimination. Aerobic exercise training promotes adaptations that include improved immune competency, higher cardiorespiratory fitness, and maintenance of hippocampal function. However, it is poorly understood whether, in active older adults, baseline immune cell profiles and cardiorespiratory fitness are possible mechanisms that facilitate the long-term benefits to hippocampal dependent mnemonic discrimination performance. This within-subjects study with counterbalanced conditions aimed to investigate whether baseline monocyte polarization and cardiorespiratory fitness influenced performance in the mnemonic similarity task (MST) and related Lure Discrimination Index (LDI) score after an acute bout of exercise. Twenty-one active older adults (M = 68 ± 5 yrs) underwent baseline testing in which blood samples were collected and cardiorespiratory fitness measured. Participants then returned and completed a seated rest or moderate intensity aerobic exercise condition in which the MST was proctored prior to and 5 min after each condition. A linear mixed effects model was used in which Participant ID was a random effect and Condition (rest v. exercise), Time (pre- v post-), and order were fixed main effects. Simple linear regression models were used to determine the variance accounted for by monocyte phenotypes and cardiorespiratory fitness for LDI scores post-condition. Post-rest LDI scores were significantly lower than post-exercise LDI scores (t(20) = -2.65, p < 0.02, d = -0.57). Intermediate monocytes were significant predictors of the change in pre- to post-exercise LDI scores (F(1, 19) = 6.03, p = 0.024, R² = 0.24) and cardiorespiratory fitness was a significant predictor of the difference between post-condition LDI scores (F(1, 19) = 6.71, p = 0.018, R² = 0.26). Our results suggest baseline cardiorespiratory fitness and intermediate monocytes may relate to the integrity of hippocampal-dependent mnemonic discrimination performance, and possibly the degree of responsiveness to aerobic exercise interventions.

Effects on Spirulina Supplementation on Immune Cells' Parameters of Elite College Athletes

Objective: To identify the effect of spirulina supplementation on the immune cells’ indicators of young soccer players during the preparation period of a tournament. Methods: 39 undergraduate male soccer players were recruited and randomly allocated into a spirulina supplementation group (SP group, n = 20) and the placebo supplementation group (PB group, n = 19). Their elbow venous blood samples were collected before and after the preparation period of a tournament, which included 8 weeks total. The differences within the group and between groups were recorded and analyzed. Results: The ratio of the basophils in the SP group between the pre-test and post-test were statistically significantly different (p < 0.05). In the PB group, the percentage of before and after in leukocytes and monocytes were statistically significantly different (p < 0.05). In the data of the post-test, the percentage of monocytes and basophils between the SP group and PB group were statistically significantly different. The delta variations of monocytes between groups were significantly different (p < 0.05). Conclusions: Intense long-duration exercise can reduce the ratio of leukocytes and monocytes in young athletes, yet the spirulina supplement can inhibit the change. It also might improve immunity to parasites, pathogenic bacterium, and rapid-onset allergies.

Lifestyle and environmental factors may induce airway and systemic inflammation in firefighters

Health status depends on multiple genetic and non-genetic factors. Nonheritable factors (such as lifestyle and environmental factors) have stronger impact on immune responses than genetic factors. Firefighters work is associated with exposure to air pollution and heat stress, as well as: extreme physical effort, mental stress, or a changed circadian rhythm, among others. All these factors can contribute to both, short-term and long-term impairment of the physical and mental health of firefighters. Increased levels of some inflammatory markers, such as pro-inflammatory cytokines or C-reactive protein (CRP) have been observed in firefighters, which can lead to local, acute inflammation that promotes a systemic inflammatory response. It is worth emphasizing that inflammation is one of the main hallmarks of cancer and also plays a key role in the development of cardiovascular and respiratory diseases. This article presents possible causes of the development of an inflammatory reaction in firefighters, with particular emphasis on airway inflammation caused by smoke exposure.

A Congested Match Schedule Alters Internal Match Load and Affects Salivary Immunoglobulin A Concentration in Youth Soccer Players

ABSTRACT

Mortatti, AL, Oliveira, RSCd, Pinto, JCBdL, Galvão-Coelho, NL, Almeida, RN, Aoki, MS, and Moreira, A. A congested match schedule alters internal match load and affects salivary immunoglobulin A concentration in youth soccer players. J Strength Cond Res 36(6): 1655-1659, 2022-The aim of this study was to analyze the effects of a congested match schedule (CMS) undertaken after a tapering week, on internal match load (IML) and salivary immunoglobulin A (SIgA) concentration in 12 youth soccer players (16.6 ± 0.5 years; 175 ± 8 cm; 65 ± 8 kg) who performed 4 official matches within a 4-day period. Internal match load was determined using the session-rating of perceived exertion method and the competitive strain (CS) and monotony index (MI) were also determined. Saliva sampling was conducted, before the last training day of a tapering week (training) preceding the CMS, 60 minutes before the first match (match-1), and 22 hours after match 4 (postmatch 4). Salivary immunoglobulin A was analyzed by ELISA. The results of the analysis of variance with repeated measures showed a significant difference for IML across the matches (p < 0.001). A significant reduction in SIgA was observed from prematch 1 to postmatch 4 (p = 0.019). Regarding the change in SIgA (ΔSIgA), 58.3% of the players presented values equal/higher than the minimal detectable change. A large within-individual correlation was observed between ΔSIgA and MI and CS (r = 0.71 and r = 0.72: p < 0.01, respectively). The current findings suggest that youth players participating in a CMS may present a decrease in mucosal immunity function. In addition, data suggest that the MI and CS may be used as valuable markers for monitoring competition load during CMS in youth soccer players.

Acute and post-acute COVID-19 presentations in athletes: a systematic review and meta-analysis

OBJECTIVE

To describe acute/postacute COVID-19 presentations in athletes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

The search was conducted in four databases (MEDLINE, EMBASE, SCOPUS, SPORTDiscus) and restricted to studies published from 2019 to 6 January 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were required to (1) include professional, amateur or collegiate/university athletes with COVID-19; (2) present data on acute/postacute COVID-19 symptoms and (3) have an observational design. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal tools.

RESULTS

43 studies with 11 518 athletes were included. For acute presentation, the pooled event rates for asymptomatic and severe COVID-19 were 25.5% (95% CI: 21.1% to 30.5%) and 1.3% (95% CI: 0.7% to 2.3%), respectively. For postacute presentations, the pooled estimate of persistent symptoms was 8.3% (95% CI: 3.8% to 17.0%). Pooled estimate for myocardial involvement was 5.0% (95% CI: 2.5% to 9.8%) in athletes undergoing any cardiac testing, and 2.5% (95% CI: 1.0% to 5.8%) in athletes undergoing MRI, although clinical symptoms were not characterised. None of the studies with a control group (eg, non-infected athletes) could confirm a causal relationship between COVID-19 and myocardial involvement.

CONCLUSION

This broad characterisation of COVID-19 presentations in athletes indicates that ~94% exhibited mild or no acute symptoms. The available evidence did not confirm a causal relationship between COVID-19 and myocardial involvement. A small proportion of athletes experienced persistent symptoms while recovering from infection, which were mostly mild in nature, but could affect return-to-play decisions and timing.

A Cocoa Diet Can Partially Attenuate the Alterations in Microbiota and Mucosal Immunity Induced by a Single Session of Intensive Exercise in Rats

Background

Following intensive sports events, a higher rate of upper respiratory tract infections and the appearance of gastrointestinal symptomatology have been reported. We aimed to evaluate the effect of a cocoa-enriched diet on the cecal microbiota and mucosal immune system of rats submitted to high-intensity acute exercise, as well as to elucidate the involvement of cocoa fiber in such effects.

Methods

Wistar rats were fed either a standard diet, a diet containing 10% cocoa providing 5% fiber and a diet containing only 5% cocoa fiber. After 25 days, half of the rats of each diet performed an exhaustion running test. Sixteen hours later, samples were obtained to assess, among others, the cecal microbiota and short chain fatty acids (SCFAs) composition, mesenteric lymph nodes (MLNs) and Peyer’s patches (PPs) lymphocyte composition, and immunoglobulin (Ig) content in salivary glands.

Results

The intake of cocoa, partially due to its fiber content, improved the SCFA production, prevented some changes in PPs and in MLNs lymphocyte composition and also decreased the production of proinflammatory cytokines. Cocoa diet, contrary to cocoa fiber, did not prevent the lower salivary IgM induced by exercise.

Conclusion

A cocoa dietary intake can partially attenuate the alterations in microbiota and mucosal immunity induced by a single session of intensive exercise.

Sports, Myocarditis and COVID-19: Diagnostics, Prevention and Return-to-Play Strategies

Myocarditis is an umbrella term for non-ischemic myocardial inflammation and remains a leading cause of sudden cardiac death in active individuals and athletes. Accurate diagnosing is challenging and diseases could often remain undetected. In the majority of cases, acute myocarditis resolves favourably. However, a relevant proportion of patients may have an increased risk of prognostically relevant cardiac arrhythmias and/or the development and progression of maladaptive myocardial remodelling (dilated cardiomyopathy). This review provides current knowledge on myocarditis and sports with special regard to the COVID-19 pandemic. Possible causes, common symptoms and proposed diagnostics are summarized. The relevance of temporary avoidance of intensive sports activities for both the prevention and therapy of acute myocarditis is discussed. Risk stratification, specific return-to-play recommendations and proposed follow-up diagnostics (also after COVID-19 infection) are presented.

Beep Test Does Not Induce Phosphorylation of Ras/MAPK- or JAK/STAT-Related Proteins in Peripheral Blood T Lymphocytes

The Th1 cell subset is involved in the immunological response induced by physical exercise. The aim of this work is to evaluate the post-effort activation of Ras/MAPK and JAK/STAT signaling pathways in T cells of young, physically active men. Seventy-six physically active, healthy men between 15 and 21 years old performed a standard physical exercise protocol (Beep test). Phosphorylation levels of Ras/MAPK-(p38 MAPK, ERK1/2) and JAK/STAT-related (STAT1, STAT3, STAT5, and STAT6) proteins were evaluated by flow cytometry in Th and Tc cells post-effort and during the lactate recovery period. The performed physical effort was not a strong enough physiological stimulant to provoke the phosphorylation of ERK1/2, p38 MAPK, STAT1, STAT3, STAT5, and STAT6 in T cells, at least for the duration of our study (the end of the lactate recovery period). We conclude that more observation time-points, including shorter and longer times after the exercise, are required to determine if the Ras/MAPK signaling pathway is involved in modulating the post-effort immunological response.

Risk factors associated with acute respiratory illnesses in athletes: a systematic review by a subgroup of the IOC consensus on ‘acute respiratory illness in the athlete’

Objective

To review risk factors associated with acute respiratory illness (ARill) in athletes, including non-infectious ARill and suspected or confirmed acute respiratory infections (ARinf).

Design

Systematic review.

Data sources

Electronic databases: PubMed-Medline, EbscoHost and Web of Science.

Eligibility criteria

Original research articles published between January 1990 and July 2020 in English were searched for prospective and retrospective full text studies that reported quantitative data on risk factors associated with ARill/ARinf in athletes, at any level of performance (elite/non-elite), aged 15–65 years.

Results

48 studies (n=19 390 athletes) were included in the study. Risk factors associated with ARill/ARinf were: increased training monotony, endurance training programmes, lack of tapering, training during winter or at altitude, international travel and vitamin D deficits. Low tear-(SIgA) and salivary-(IgA) were immune biomarkers associated with ARill/ARinf.

Conclusions

Modifiable training and environmental risk factors could be considered by sports coaches and athletes to reduce the risk of ARill/ARinf. Clinicians working with athletes can consider assessing and treating specific nutritional deficiencies such as vitamin D. More research regarding the role and clinical application of measuring immune biomarkers in athletes at high risk of ARill/ARinf is warranted.

PROSPERO registration number

CRD42020160928.

The Relationship Between Dietary Intake and Sleep Quality in Endurance Athletes

Many endurance athletes have poor sleep quality which may affect performance and health. It is unclear how dietary intake affects sleep quality among athletes. We examined if sleep quality in endurance athletes is associated with consumption of fruit, vegetables, whole grains, dairy milk, and caffeinated beverages. Two hundred thirty-four endurance athletes (39.5 ± 14.1 year) participated in a survey. Participants provided information on demographics, anthropometry, sleep behavior and quality, and dietary intake via questionnaires. Sleep quality was assessed using the Athlete Sleep Screening Questionnaire (ASSQ) with a global score (ASSQ-global) and subscales including sleep difficulty (ASSQ-SD), chronotype (ASSQ-C), and disordered breathing while sleeping (ASSQ-SDB). A general linear model (GLM), adjusted for age, body mass index, sleep discomfort, sleep behavior, gender, race, and ethnicity, showed that higher caffeinated beverage intake was related to poorer global sleep quality (p = 0.01) and increased risk for disordered breathing while sleeping (p = 0.03). Higher whole grain intake was associated with a morning chronotype and lower risk for sleep issues (p = 0.01). The GLM did not reveal a relationship between sleep quality and dairy milk, fruit, and vegetable intake. In conclusion, caffeinated beverages and whole grain intake may influence sleep quality. This relationship needs to be confirmed by further research.

Interdisciplinary Approach to Biological and Health Implications in Selected Professional Competences

Everyday life’s hygiene and professional realities, especially in economically developed countries, indicate the need to modify the standards of pro-health programs as well as modern hygiene and work ergonomics programs. These observations are based on the problem of premature death caused by civilization diseases. The biological mechanisms associated with financial risk susceptibility are well described, but there is little data explaining the biological basis of neuroaccounting. Therefore, the aim of the study was to present relationships between personality traits, cognitive competences and biological factors shaping behavioral conditions in a multidisciplinary aspect. This critical review paper is an attempt to compile biological and psychological factors influencing the development of professional competences, especially decent in the area of accounting and finance. We analyzed existing literature from wide range of scientific disciplines (including economics, psychology, behavioral genetics) to create background to pursuit multidisciplinary research models in the field of neuroaccounting. This would help in pointing the best genetically based behavioral profile of future successful financial and accounting specialists.

Illness Incidence, Psychological Characteristics, and Sleep in Dogsled Drivers During the Iditarod Trail Sled Dog Race

INTRODUCTION

Every March, dogsled drivers (mushers) compete in a 1569-km race across Alaska, involving physical exertion, mental exertion, and sleep deprivation for up to 2 wk. These factors may increase mushers' vulnerability to illness, making them a relevant study population for acute infection risk factors. Specifically, the influence of psychological factors on illness risk during prolonged physical exertion has rarely been investigated. The aim of this study was to examine the relationship between psychological characteristics, sleep deprivation, and illness incidence in Iditarod mushers.

METHODS

Fourteen mushers completed 4 psychological instruments to assess state and trait anxiety, resilience and perceived stress, and self-reported upper respiratory symptoms (URS) in the month before the race. Mushers self-reported sleep duration and URS during the race.

RESULTS

State and trait anxiety, resilience, and perceived stress did not differ between mushers with and without pre- and in-race URS (P>0.05). However, all mushers who reported in-race URS had reported URS ≤9 d before the race, and the onset of symptoms during the race typically occurred shortly after a rest period. Sleep duration was higher in mushers who reported in-race URS, both before (4.9±0.3 h, P=0.016) and during illness (5.9±1.3 h, P=0.006), vs mushers without in-race URS (3.4±0.8 h).

CONCLUSIONS

This study highlights recent illness, rest periods, and greater sleep requirements as potential risk factors for URS onset during a multiday endurance challenge, whereas psychological factors were not associated with URS.

Comparing National Collegiate Athletic Association Division II Athletes’ Perceptions of Social Support Following Injury, Illness, and Other Identified Stressors

Collegiate athletes have demonstrated a need for social support to help cope with their daily responsibilities. The purpose of this research was to explore National Collegiate Athletic Association Division II athletes’ perception of social support from friends, teammates, family, coaches, significant others, and athletic trainers following injury, illness, or other identified life stressors. There were 546 participants who completed a five-part survey using the University Stress Scale, the Multidimensional Scale of Perceived Social Support, the Athletic Multidimensional Scale of Perceived Social Support, the Perceived Stress Scale, and a demographic section. Of the participants, 352 (64.5%) stated that they experienced moderate stress levels, and all participants indicated experiencing an identified life stressor within the last 12 months. The results indicated statistically significant differences when comparing providers of social support: females preferred the support of friends, significant others, and athletic trainers, and freshmen and sophomores perceived more social support from friends than did juniors and seniors.

“Food First but Not Always Food Only”: Recommendations for Using Dietary Supplements in Sport

The term “food first” has been widely accepted as the preferred strategy within sport nutrition, although there is no agreed definition of this and often limited consideration of the implications. We propose that food first should mean “where practically possible, nutrient provision should come from whole foods and drinks rather than from isolated food components or dietary supplements.” There are many reasons to commend a food first strategy, including the risk of supplement contamination resulting in anti-doping violations. However, a few supplements can enhance health and/or performance, and therefore a food only approach could be inappropriate. We propose six reasons why a food only approach may not always be optimal for athletes: (a) some nutrients are difficult to obtain in sufficient quantities in the diet, or may require excessive energy intake and/or consumption of other nutrients; (b) some nutrients are abundant only in foods athletes do not eat/like; (c) the nutrient content of some foods with established ergogenic benefits is highly variable; (d) concentrated doses of some nutrients are required to correct deficiencies and/or promote immune tolerance; (e) some foods may be difficult to consume immediately before, during or immediately after exercise; and (f) tested supplements could help where there are concerns about food hygiene or contamination. In these situations, it is acceptable for the athlete to consider sports supplements providing that a comprehensive risk minimization strategy is implemented. As a consequence, it is important to stress that the correct terminology should be “food first but not always food only.”

The Recovery Umbrella in the World of Elite Sport: Do Not Forget the Coaching and Performance Staff

In the field of sports science, the recovery umbrella is a trending topic, and even more so in the world of elite sports. This is evidenced by the significant increase in scientific publications during the last 10 years as teams look to find a competitive edge. Recovery is recognized to be an integral component to assist athlete preparation in the restoration of physical and psychological function, and subsequently, performance in elite team sports athletes. However, the importance of recovery in team staff members (sports coaches and performance staff) in elite sports appears to be a forgotten element. Given the unrelenting intense nature of daily tasks and responsibilities of team staff members, the elite sports environment can predispose coaches to increased susceptibility to psycho-socio physiological fatigue burden, and negatively affect health, wellbeing, and performance. Therefore, the aim of this opinion was to (1) develop an educational recovery resource for team staff members, (2) identify organizational task-specific fatigue indicators and barriers to recovery and self-care in team staff members, and (3) present recovery implementation strategies to assist team staff members in meeting their organizational functions. It is essential that we do not forget the coaching and performance staff in the recovery process.

Moderate Intensity Aerobic Exercise Potential Favorable Effect Against COVID-19: The Role of Renin-Angiotensin System and Immunomodulatory Effects

The coronavirus disease (COVID-19) pandemic is caused by a novel coronavirus (CoV) named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As the angiotensin converting enzyme 2 (ACE2) is the cellular receptor of SARS-CoV-2, it has a strong interaction with the renin angiotensin system (RAS). Experimental studies have shown that the higher levels of ACE2 or increasing ACE2/ACE1 ratio improve COVID-19 outcomes through lowering inflammation and death. Aerobic moderate intensity physical exercise fights off infections by two mechanisms, the inhibition of ACE/Ang II/AT1-R pathway and the stimulation of ACE2/Ang-(1-7)/MasR axis. Exercise can also activate the anti-inflammatory response so that it can be a potential therapeutic strategy against COVID-19. Here, we summarize and focus the relation among COVID-19, RAS, and immune system and describe the potential effect of aerobic moderate intensity physical exercise against CoV as a useful complementary tool for providing immune protection against SARS-CoV-2 virus infection, which is a novel intervention that requires further investigation.

Efficacy of immune-strengthening functional drinks in top-level athletes: a questionnaire survey-based research

PURPOSE

Functional beverages are intended to support those who want to maintain optimal physical condition and improve their quality of life through the enhancement of heart health, immunity, and digestion. The purpose of this study was to investigate the performance of top-level athletes consuming immune-strengthening conditioning nutritional drinks.

METHODS

A total of 107 top-level athletes (baseball (56 players), pro volleyball (17), athletics (16), cycling (8), golf (6), and fencing (6)) participated in the experiment. They consumed an immune-enhancing functional beverage once a day for 8 weeks and responded to a survey before, during, and after drinking the beverage.

RESULTS

Three total aspect-based subfactors were drawn from 24 questions in the factor analysis: physical, satisfaction with mental stability, and activity in performance. The physical, mental stability and performance changes of athletes significantly increased in period 2 (4 weeks after intake) and period 3 (after 8 weeks of intake).

CONCLUSION

We evaluated the efficacy of a new conditioned beverage containing Lactobacillus B240 and protein in improving the performance and physiological utility of top athletes. This functional drink may gain popularity among those seeking health benefits and improved exercise performance.

Inflammatory response of the peripheral neuroendocrine system following downhill running

Exploring the relationship between exercise inflammation and the peripheral neuroendocrine system is essential for understanding how acute or repetitive bouts of exercise can contribute to skeletal muscle adaption. In severe damage, some evidence demonstrates that peripheral neuroendocrine receptors might contribute to inflammatory resolution, supporting the muscle healing process through myogenesis. In this sense, the current study aimed to evaluate two classic peripheral neuronal receptors along with skeletal muscle inflammation and adaptation parameters in triceps brachii after exercise. We euthanized C57BL (10 to 12 weeks old) male mice before, and one, two, and three days after a downhill running protocol. The positive Ly6C cells, along with interleukin-6 (IL-6), nuclear factor kappa B (NF-κB), glucocorticoid receptor (GR), α7 subunits of the nicotinic acetylcholine receptor (nAChRs), and myonuclei accretion were analyzed. Our main results demonstrated that nAChRs increased with the inflammatory and myonuclei accretion responses regardless of NF-κB and GR protein expression. These results indicate that increased nAChR may contribute to skeletal muscle adaption after downhill running in mice.

A 5-Year Analysis of Weight Cycling Practices in a Male World Champion Professional Boxer: Potential Implications for Obesity and Cardiometabolic Disease

Weight cycling is thought to increase the risk of obesity and cardiometabolic disease in nonathletic and athletic populations. However, the magnitude and frequency of weight cycling is not well characterized in elite athletes. To this end, we quantified the weight cycling practices of a male World Champion professional boxer competing at super middleweight (76.2 kg). Over a 5-year period comprising 11 contests, we assessed changes in body mass (n = 8 contests) and body composition (n = 6 contests) during the training camp preceding each contest. Time taken to make weight was 11 ± 4 weeks (range: 4-16). Absolute and relative weight loss for each contest was 12.4 ± 2.1 kg (range: 9.8-17.0) and 13.9% ± 2.0% (range: 11.3-18.2), respectively. Notably, the athlete commenced each training camp with progressive increases in fat mass (i.e., 12.5 and 16.1 kg for Contests 1 and 11) and reductions in fat-free mass (i.e., 69.8 and 67.5 kg for Contests 1 and 11, respectively). Data suggest that weight cycling may lead to "fat overshooting" and further weight gain in later life. Larger scale studies are now required to characterize the weight cycling practices of elite athletes and robustly assess future cardiometabolic disease risk. From an ethical perspective, practitioners should be aware of the potential health consequences associated with weight cycling.

Acute and Chronic Effects of Interval Training on the Immune System: A Systematic Review with Meta-Analysis

Simple Summary

Interval training (IT) is a popular training strategy recognized by its positive effects on metabolic and cardiovascular system. However, there seems no consensus regarding the effects of IT on immune system parameters. Therefore, we aimed to summarize the evidence regarding the effects of IT on the immune system. As our many findings, an IT acutely promote a transitory change on immune cell count followed by reduced function. The magnitude of these changes seems to vary in accordance with IT type. On the other hand, the regular practice of IT might contribute to improve immune function without apparent change on immune cell count.

Abstract

Purpose: To summarize the evidence regarding the acute and chronic effects of interval training (IT) in the immune system through a systematic review with meta-analysis. Design: Systematic review with meta-analysis. Data source: English, Portuguese and Spanish languages search of the electronic databases Pubmed/Medline, Scopus, and SciELO. Eligibility criteria: Studies such as clinical trials, randomized cross-over trials and randomized clinical trials, investigating the acute and chronic effects of IT on the immune outcomes in humans. Results: Of the 175 studies retrieved, 35 were included in the qualitative analysis and 18 in a meta-analysis. Within-group analysis detected significant acute decrease after IT on immunoglobulin A (IgA) secretory rate (n = 115; MD = −15.46 µg·min⁻¹; 95%CI, −28.3 to 2.66; p = 0.02), total leucocyte count increase (n = 137; MD = 2.58 × 10³ µL⁻¹; 95%CI, 1.79 to 3.38; p < 0.001), increase in lymphocyte count immediately after exercise (n = 125; MD = 1.3 × 10³ µL⁻¹; 95%CI, 0.86 to 1.75; p < 0.001), and decrease during recovery (30 to 180 min post-exercise) (n = 125; MD = −0.36 × 10³ µL⁻¹;−0.57 to −0.15; p < 0.001). No effect was detected on absolute IgA (n = 127; MD = 47.5 µg·mL⁻¹; 95%CI, −10.6 to 105.6; p = 0.11). Overall, IT might acutely reduce leucocyte function. Regarding chronic effects IT improved immune function without change leucocyte count. Conclusion: IT might provide a transient disturbance on the immune system, followed by reduced immune function. However, regular IT performance induces favorable adaptations on immune function.

Analysis of Selected Lymphocyte (CD45+) Subset Distribution in Capillary Blood of Young Soccer Players

ABSTRACT

Nowak, R, Kostrzerwa-Nowak, D, and Buryta, R. Analysis of selected lymphocyte (CD45+) subset distribution in capillary blood of young soccer players. J Strength Cond Res 35(8): 2279-2286, 2021-Mechanisms responsible for increasing athletes' physical capacity and induction of exercise-induced immunosuppression processes are not fully understood. The aim of the study was to monitor changes in percentages of lymphocyte subsets: T, Th, Tc, B, and NK cells in capillary blood of junior soccer players. Ten subjects median aged 18 years (range 17-19 years) were recruited form young soccer players. Capillary blood was collected 24 hours after each soccer match during the 8 weeks of the final phase of Central Junior League competition, and white blood cell (WBC) phenotyping was performed to determine the percentages of B lymphocytes, NK cells, and T-lymphocyte subsets. Cumulative match-time (a sum of time spend playing the game by each athlete during the observation period) was also calculated. Significant changes in the percentage of total lymphocytes (p = 0.00005) and T cells (p = 0.00006) were observed. The slight increases in lymphocytes' and Th cells' median percentages correlated with increasing cumulative match-time of studied subjects, although the correlation was not strong (R = 0.24; p = 0.0205 and R = 0.30; p = 0.0035, for lymphocytes and Th cells, respectively). It seems that the exercise bouts are among considerable factors influencing the changes in WBC subsets, especially in CD3+ cells, among young soccer players. Regarding the number of games played and training loads, they are more susceptible to immunosuppression and subsequent infections and thus should be monitored regarding WBC phenotype assessment.

Endocrine disrupting chemicals (EDCs) and the neuroendocrine system: Beyond estrogen, androgen, and thyroid

Hundreds of anthropogenic chemicals occupy our bodies, a situation that threatens the health of present and future generations. This chapter focuses on endocrine disrupting compounds (EDCs), both naturally occurring and man-made, that affect the neuroendocrine system to adversely impact health, with an emphasis on reproductive and metabolic pathways. The neuroendocrine system is highly sexually dimorphic and essential for maintaining homeostasis and appropriately responding to the environment. Comprising both neural and endocrine components, the neuroendocrine system is hormone sensitive throughout life and touches every organ system in the body. The integrative nature of the neuroendocrine system means that EDCs can have multi-system effects. Additionally, because gonadal hormones are essential for the sex-specific organization of numerous neuroendocrine pathways, endocrine disruption of this programming can lead to permanent deficits. Included in this review is a brief history of the neuroendocrine disruption field and a thorough discussion of the most common and less well understood neuroendocrine disruption modes of action. Also provided are extensive examples of how EDCs are likely contributing to neuroendocrine disorders such as obesity, and evidence that they have the potential for multi-generational effects.

Immunometabolic responses according to physical fitness status and lifelong exercise during aging: New roads for exercise immunology

Molecules such as cytokines, energetic substrates, and hormones found in the immune cell environment, especially lymphocytes and monocytes, are crucial for directing energy metabolism. In turn, changes in energy metabolism occur in a synchronized manner with the activation of certain signaling pathways, thereby this crosstalk is responsible for determining the functionality of immune cells. The immunometabolism field has grown over time and that is becoming increasingly promising in several populations; here we discuss the mechanisms involved in sedentary and physically active middle-aged individuals and master athletes. In this context, this review shows that the physical activity status and lifelong exercise seems to be good strategies for the promotion of metabolic and functional adaptations in T lymphocytes and monocytes, counteracting inflammatory environments caused by expanded adipose tissue and sedentary behavior, as well as delaying the immunosenescence caused by aging.

Influence of Vitamin D Supplementation by Simulated Sunlight or Oral D3 on Respiratory Infection during Military Training

PURPOSE

This study aimed to determine the relationship between vitamin D status and upper respiratory tract infection (URTI) of physically active men and women across seasons (study 1) and then to investigate the effects on URTI and mucosal immunity of achieving vitamin D sufficiency (25(OH)D ≥50 nmol·L-1) by a unique comparison of safe, simulated sunlight or oral D3 supplementation in winter (study 2).

METHODS

In study 1, 1644 military recruits were observed across basic military training. In study 2, a randomized controlled trial, 250 men undertaking military training received placebo, simulated sunlight (1.3× standard erythemal dose, three times per week for 4 wk and then once per week for 8 wk), or oral vitamin D3 (1000 IU·d-1 for 4 wk and then 400 IU·d-1 for 8 wk). URTI was diagnosed by a physician (study 1) and by using the Jackson common cold questionnaire (study 2). Serum 25(OH)D, salivary secretory immunoglobulin A (SIgA), and cathelicidin were assessed by liquid chromatography-mass spectrometry LC-MS/MS and enzyme-linked immunosorbent assay.

RESULTS

In study 1, only 21% of recruits were vitamin D sufficient during winter. Vitamin D-sufficient recruits were 40% less likely to suffer URTI than recruits with 25(OH)D <50 nmol·L-1 (OR = 0.6, 95% confidence interval = 0.4-0.9), an association that remained after accounting for sex and smoking. Each URTI caused, on average, three missed training days. In study 2, vitamin D supplementation strategies were similarly effective to achieve vitamin D sufficiency in almost all (≥95%). Compared with placebo, vitamin D supplementation reduced the severity of peak URTI symptoms by 15% and days with URTI by 36% (P < 0.05). These reductions were similar with both vitamin D strategies (P > 0.05). Supplementation did not affect salivary secretory immunoglobulin A or cathelicidin.

CONCLUSION

Vitamin D sufficiency reduced the URTI burden during military training.

Sleep disruption considerations for Paralympic athletes competing at Tokyo 2020

The role of sleep is now recognized as an important component for success in athletic performance, and sleep is proposed to be one of the most effective recovery strategies available. Insufficient sleep is commonly reported among athletes while several factors have been put forward to explain why elite athletes might experience poor sleep. However, Paralympic athletes may be predisposed to a greater risk of poor sleep due to the associated complexities of some impairment types. In fact, clinical research has previously shown that individuals with disabilities have a higher prevalence of sleep disturbances when compared to their able-bodied counterparts. However, research and evidence-based practices regarding the sleep of elite Paralympic athletes are limited. Firstly, this narrative review aims to identify challenges associated with the Paralympic games to obtain optimal sleep. Secondly, identify the specific risk factors to sleep associated with particular impairment groups within the Paralympic population, and lastly to propose potential sleep-enhancing strategies that might be of relevance for Paralympic athletes. From this review, initial observations have identified that Paralympic athletes may have a heightened risk of sleep-related problems, and importantly highlighted the current lack of understanding within this population group. Furthermore, this review identified where further research is warranted to better understand how specific impairments impact sleep and, consequently, athletic performance. Additionally, this review highlighted that the forthcoming Tokyo games may offer a unique challenge for athletes trying to obtain optimal sleep, due to the anticipated thermal demands and the consequent irregular scheduling of events.