Upper Respiratory Tract Diseases in Athletes in Different Sports Disciplines

Reported COVID-19 vaccines side effects among Algerian athletes: a comparison between inactivated virus, adenoviral vector, and mRNA COVID-19 vaccines

OBJECTIVES

Many types of COVID19 vaccines are administered globally, yet there is not much evidence regarding their side effects among athletes. This study evaluated the selfreported postvaccination side effects of inactivated virus, adenoviral vector, and mRNA COVID19 vaccines among Algerian athletes.

METHODS

A cross-sectional survey-based study was carried out in Algeria between March 01 and 4 April 2022. The study used a validated questionnaire with twenty-five multiple-choice items covering the participants' anamnestic characteristics, post-vaccination side effects (their onset and duration), post-vaccination medical care, and risk factors.

RESULTS

A total of 273 athletes completed the survey. Overall, (54.6%) of the athletes reported at least one local side effect, while (46.9%) reported at least one systemic side effect. These side effects were more prevalent among the adenoviral vector group compared to the inactivated virus and mRNA groups. The most common local side effect was injection site pain (29.9%), while Fever (30.8%) was the most prevalent systemic side effect. The age group of 31-40 years, allergy, previous infection with COVID-19, and the first dose of vaccines were associated with an increased risk of side effects for all groups of COVID-19 vaccines. Logistic regression analysis further revealed that compared to males, the incidence of reported side effects was significantly higher in females (odd ratio (OR) = 1.16; P = 0.015*) only for the adenoviral vector vaccine group. In addition, a significantly higher percentage of athletes group of high dynamic/moderate static or high dynamic /high static components suffered from post-vaccination side effects compared to the group of athletes with high dynamic/low static components (OR = 14.68 and 14.71; P < 0.001, respectively).

CONCLUSIONS

The adenoviral vector vaccines have the highest rate of side effects, followed by the inactivated virus and mRNA COVID-19 vaccines. COVID‑19 vaccines were well-tolerated among Algerian athletes and there were no reports of serious side effects. Nevertheless, further long-term follow-up study with a larger sample size of athletes (from different types and sports categories) is warranted to establish the long-term safety of the COVID-19 vaccine.

Use of pharmaceuticals amongst athletes tested by Anti-Doping Norway in a five-year period

Introduction

The aim of the study was to map the use of pharmaceuticals by Norwegian athletes registered on doping control forms (DCFs) in a five-year period to examine general and some class specific use of pharmaceuticals across sports and athlete levels.

Method

Anonymous data from DCFs collected in 2015-2019 were manually entered into a database using the Anatomical Therapeutic Chemical (ATC) system for classification of the pharmaceuticals. Variables entered were year of control, gender, age group, athlete level, sport, test type, nationality, and pharmaceuticals (and dietary supplements) used.

Results

Pain killers in the ATC groups M01 A (Nonsteroidal anti-inflammatory drugs - NSAIDs) and N02 B (other analgesics), and anti-asthmatics in ATC groups R03 A and R03 B were the most frequently used pharmaceuticals. National level athletes reported more use of pharmaceuticals (1.4 ± 1.7 pharmaceuticals per form) than recreational level athletes (0.9 ± 1.2). The highest proportion of DCFs containing information about at least one pharmaceutical were found in speed skating (79.1%), alpine skiing (74.0%), rowing (72.4%) and cross-country skiing (71.7%). Painkillers were most frequently used in muscular endurance sports (30.4% and 21.2 % for M01A and N02 B, respectively) and ball and team sports (17.9% and 17.0%). Use of hypnotics was reported from ice-hockey players and alpine skiers in around 8% of the cases.

Coclusion

Use of anti-asthmatics was most often reported amongst athletes specially exposed to cold, chemicals and heavy endurance training. Athletes in specialized sports requiring high levels of strength and/or endurance reported a higher use of pharmaceuticals out-of-competition compared to in-competition, while there was no such difference in complex sports, such as team, gymnastic, aiming and combat sports.

Importance of "meal first" strategy and effective situations of supplement use in elite athletes: Japan high performance sport center position stand

The "meal first" strategy is traditionally recommended for athletes' conditioning. However, the importance of the "meal first" principle has not been detailly well documented in athletes' lives. Supplement use has recently become a common part of athletes' diets, but unmonitored supplement use can cause negative consequences, such as anti-doping violations and health issues. Therefore, this review summarizes how the "meal first" strategy and planned supplement use are important for enhancing athletes' health and performance. We believe that the "meal first" strategy is beneficial in terms of the following aspects: (1) consumption of multi-nutrients and other functional components simultaneously; (2) positive effects on psychological well-being; (3) contribution to athletes' health by way of mastication; and (4) less risk for anti-doping violations. Before supplement use, we recommend that athletes first verify their basic factors (e.g., diet, training, and sleep), given that the benefits of supplements are examined and demonstrated with the control of those factors. Otherwise, athletes cannot obtain maximal benefits from the supplements. In contrast, there are situations in which supplements in athletes' lives can be advantageous, such as (1) nutrient deficiency due to ongoing dietary characteristics; (2) interruption of meals due to disease; (3) inaccessibility of quality food during athletic travel; (4) difficulty preparing food due to societal restrictions associated with disasters or infection outbreaks; (5) having a meal before, during, or after exercise is difficult; and (6) achieving targeted intake of performance-enhancing ingredients is not practical. In summary, we emphasize that the "meal first" strategy is recommended for athletes' conditioning, but there are several contexts when supplement use can be more useful in athletes' lives.

Changes in Immune Function during Initial Military Training

PURPOSE

Initial military training (IMT) is a transitionary period wherein immune function may be suppressed and infection risk heightened due to physical and psychological stress, communal living, and sleep deprivation. This study characterized changes in biomarkers of innate and adaptive immune function, and potential modulators of those changes, in military recruits during IMT.

METHODS

Peripheral leukocyte distribution and mitogen-stimulated cytokine profiles were measured in fasted blood samples, Epstein-Barr (EBV), varicella zoster (VZV), and herpes simplex 1 (HSV1) DNA was measured in saliva by quantitative polymerase chain reaction as an indicator of latent herpesvirus reactivation, and diet quality was determined using the healthy eating index measured by food frequency questionnaire in 61 US Army recruits (97% male) at the beginning (PRE) and end (POST) of 22-wk IMT.

RESULTS

Lymphocytes and terminally differentiated cluster of differentiation (CD)4+ and CD8+ T cells increased PRE to POST, whereas granulocytes, monocytes, effector memory CD4+ and CD8+ T cells, and central memory CD8+ T cells decreased ( P ≤ 0.02). Cytokine responses to anti-CD3/CD28 stimulation were higher POST compared with PRE, whereas cytokine responses to lipopolysaccharide stimulation were generally blunted ( P < 0.05). Prevalence of EBV reactivation was higher at POST ( P = 0.04), but neither VZV nor HSV1 reactivation was observed. Diet quality improvements were correlated with CD8+ cell maturation and blunted proinflammatory cytokine responses to anti-CD3/CD28 stimulation.

CONCLUSIONS

Lymphocytosis, maturation of T-cell subsets, and increased T-cell reactivity were evident POST compared with PRE IMT. Although EBV reactivation was more prevalent at POST, no evidence of VZV or HSV1 reactivation, which are more common during severe stress, was observed. Findings suggest increases in the incidence of EBV reactivation were likely appropriately controlled by recruits and immune-competence was not compromised at the end of IMT.

Clinical benefits of β-glucan supplementation in children: a review

Malnutrition is a global concern since it affects 130 million children under the age of 5 worldwide. The child’s immunity is brutally compromised, making them susceptible to various diseases and infections, leading to a high mortality rate. Multiple strategies have been implemented to strengthen immunity in children with compromised immunity, such as rendering a balanced diet, fortifying food, dietary supplements, and introducing potential natural dietary fibers to maintain good nutrition status, such as β-glucan. A class of biologically active polysaccharides, sourced from yeast, mushroom, bacteria, and cereals with versatile immunomodulatory benefits that potentially primes the host immune system, drives several metabolic health effects, increases infection resistance, shields against the damaging effects of stress, and maintains healthy energy levels. This review focuses on the capabilities, underlying mechanisms, immune-stimulating potency, and clinically meaningful shreds of evidence to substantiate the multiple health benefits of β-glucan in children. Although, more clinical studies are required, current findings confirms the various biological response modifying abilities of β-glucan that may notably aid in the development of a strong immune system in children for their overall health and wellbeing.

The effects of acute respiratory illness on exercise and sports performance outcomes in athletes - a systematic review by a subgroup of the IOC consensus group on "Acute respiratory illness in the athlete"

Acute respiratory infections (ARinf) are common in athletes, but their effects on exercise and sports performance remain unclear. This systematic review aimed to determine the acute (short-term) and longer-term effects of ARinf, including SARS-CoV-2 infection, on exercise and sports performance outcomes in athletes. Data sources searched included PubMed, Web of Science, and EBSCOhost, from January 1990-31 December 2021. Eligibility criteria included original research studies published in English, measuring exercise and/or sports performance outcomes in athletes/physically active/military aged 15-65years with ARinf. Information regarding the study cohort, diagnostic criteria, illness classification, and quantitative data on the effect on exercise/sports performance were extracted. Database searches identified 1707 studies. After full text screening, 17 studies were included (n = 7793). Outcomes were acute or longer-term effects on exercise (cardiovascular or pulmonary responses), or sports performance (training modifications, change in standardised point scoring systems, running biomechanics, match performance or ability to start/finish an event). There was substantial methodological heterogeneity between studies. ARinf was associated with acute decrements in sports performance outcomes (4 studies) and pulmonary function (3 studies), but minimal effects on cardiorespiratory endurance (7 studies in mild ARinf). Longer-term detrimental effects of ARinf on sports performance (6 studies) were divided. Training mileage, overall training load, standardised sports performance-dependent points and match play can be affected over time. Despite few studies, there is a trend towards impairment in acute and longer-term exercise and sports outcomes after ARinf in athletes. Future research should consider a uniform approach to explore relationships between ARinf and exercise/sports performance.

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.

Incidence of acute respiratory illnesses in athletes: a systematic review and meta-analysis by a subgroup of the IOC consensus on 'acute respiratory illness in the athlete'

OBJECTIVE

To determine the incidence of acute respiratory illness (ARill) in athletes and by method of diagnosis, anatomical classification, ages, levels of performance and seasons.

DESIGN

Systematic review and meta-analysis.

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 reporting the incidence of ARill in athletes, at any level of performance (elite/non-elite), aged 15-65 years.

RESULTS

Across all 124 studies (n=1 28 360 athletes), the incidence of ARill, estimated by dividing the number of cases by the total number of athlete days, was 4.7 (95% CI 3.9 to 5.7) per 1000 athlete days. In studies reporting acute respiratory infections (ARinf; suspected and confirmed) the incidence was 4.9 (95% CI 4.0 to 6.0), which was similar in studies reporting undiagnosed ARill (3.7; 95% CI 2.1 to 6.7). Incidences of 5.9 (95% CI 4.8 to 7.2) and 2.8 (95% CI 1.8 to 4.5) were found for studies reporting upper ARinf and general ARinf (upper or lower), respectively. The incidence of ARinf was similar across the different methods to diagnose ARinf. A higher incidence of ARinf was found in non-elite (8.7; 95% CI 6.1 to 12.5) vs elite athletes (4.2; 95% CI 3.3 to 5.3).

SUMMARY/CONCLUSIONS

These findings suggest: (1) the incidence of ARill equates to approximately 4.7 per athlete per year; (2) the incidence of upper ARinf was significantly higher than general (upper/lower) ARinf; (3) elite athletes have a lower incidence of ARinf than non-elite athletes; (4) if pathogen identification is not available, physicians can confidently use validated questionnaires and checklists to screen athletes for suspected ARinf. For future studies, we recommend that a clear diagnosis of ARill is reported.

PROSPERO REGISTRATION NUMBER

CRD42020160472.

A Guide to Different Intensities of Exercise, Vaccination, and Sports Nutrition in the Course of Preparing Elite Athletes for the Management of Upper Respiratory Infections during the COVID-19 Pandemic: A Narrative Review

Elite athletes use high-intensity training to maintain their fitness level. However, intense training can harm the immune system, making athletes suspectable to COVID-19 and negatively affecting their performance. In addition, the diet of athletes should be appreciated more as it is another influencer of the immune system, especially during the COVID 19 pandemic. The other important issue elite athletes face currently is vaccination and its possible intervention with their training. The present study attempts to discuss the impact of different training intensities, nutritional strategies, and vaccination on the immune system function in elite athletes. To this end, Scopus, ISC, PubMed, Web of Science, and Google Scholar databases were searched from 1988 to 2021 using the related keywords. The results of our review showed that although high-intensity exercise can suppress the immune system, elite athletes should not stop training in the time of infection but use low- and moderate-intensity training. Moderate-intensity exercise can improve immune function and maintain physical fitness. In addition, it is also better for athletes not to undertake high-intensity training at the time of vaccination, but instead perform moderate to low-intensity training. Furthermore, nutritional strategies can be employed to improve immune function during high-intensity training periods.

The Athlete Gut Microbiome and its Relevance to Health and Performance: A Review

The human gut microbiome is a complex ecosystem of microorganisms that play an important role in human health, influencing functions such as vitamin uptake, digestion and immunomodulation. While research of the gut microbiome has expanded considerably over the past decade, some areas such as the relationship between exercise and the microbiome remain relatively under investigated. Despite this, multiple studies have shown a potential bidirectional relationship between exercise and the gut microbiome, with some studies demonstrating the possibility of influencing this relationship. This, in turn, could provide a useful route to influence athletic performance via microbiome manipulation, a valuable prospect for many elite athletes and their teams. The evidence supporting the potential benefits of pursuing this route and associated future perspectives are discussed in this review.

Safety and Impact on Training of the Influenza Vaccines in Elite Athletes Participating in the Rio 2016 Olympics

OBJECTIVE

The aim of the study was to evaluate the safety and tolerance of influenza vaccines for the northern and southern hemispheres in Polish elite athletes participating in the Rio 2016 Olympics.

DESIGN

Prospective, observational, cohort study.

SETTING

Institutional level.

PARTICIPANTS

Ninety-seven athletes vaccinated only with the northern hemisphere vaccine; 98 athletes received the southern hemisphere vaccine alone, whereas 39 athletes were vaccinated with both vaccines.

INTERVENTIONS

The athletes were vaccinated with a trivalent, inactivated influenza vaccine recommended for the northern hemisphere 2015/2016 and then with the vaccine recommended for the southern hemisphere 2016. Athletes kept a diary of adverse events and effects (if any) on training for 6 days after vaccination.

MAIN OUTCOME MEASURES

The percentage of general and local adverse events, number of lost or modified training sessions.

RESULTS

Significantly more local adverse events (pain and redness) were found in the group immunized with the vaccine for the northern hemisphere. There were no differences in the frequency of general adverse events and influence on training between groups. Of total 273 athletes who had 1911 training days during 6 days after vaccination, 6 athletes (2.2%) lost 13 training days (0.7%) and 16 athletes (5.9%) had to modify 34 (1.7%) training days within first 2 days after vaccination.

CONCLUSIONS

Athletes tolerated influenza immunization well. If they are going to travel to the other hemisphere during the influenza season, the use of the second influenza vaccine should be advised. Athletes should anticipate modification of trainings for 2 days after vaccination.

Hematologic Disorders of COVID-19 and Appropriate Intensity of Exercise in Coronavirus Prevalence Period

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Data collection of safety accidents in sports training of athletes with Internet of Things technology

The Internet of Things (IoT) technology is an information technology developed in recent years with the development of electronic sensors, intelligence, network transmission and control technologies. This is the third revolution in the development of information technology. This article aims to study the algorithm of the Internet of Things technology, through the investigation of the hazards of athletes’ sports training, scientifically and rationally use the Internet of Things technology to collect data on safety accidents in athletes’ sports training, thereby reducing the risk of athletes’ sports training and making athletes better. In this article, the methods of literature research, analysis and condensing, questionnaire survey, theory and experiment combination, etc., investigate the safety accident data collection of the Internet of Things technology in athletes’ sports training, and provide certain theories and methods for future in-depth research practice basis. The experimental results in this article show that 82% of athletes who are surveyed under the Internet of Things technology will have partial injuries during training, reducing the risk of safety accidents in athletes’ sports training, and better enabling Chinese athletes to achieve a consistent level of competition and performance through a virtuous cycle of development.

Immunomodulating Effects of Fungal Beta-Glucans: From Traditional Use to Medicine

The importance of a well-functioning and balanced immune system has become more apparent in recent decades. Various elements have however not yet been uncovered as shown, for example, in the uncertainty on immune system responses to COVID-19. Fungal beta-glucans are bioactive molecules with immunomodulating properties. Insights into the effects and function of beta-glucans, which have been used in traditional Chinese medicine for centuries, advances with the help of modern immunological and biotechnological methods. However, it is still unclear into which area beta-glucans fit best: supplements or medicine? This review has highlighted the potential application of fungal beta-glucans in nutrition and medicine, reviewing their formulation, efficacy, safety profile, and immunomodulating effects. The current status of dietary fungal glucans with respect to the European scientific requirements for health claims related to the immune system and defense against pathogens has been reviewed. Comparing the evidence base of the putative health effects of fungal beta-glucan supplements with the published guidance documents by EFSA on substantiating immune stimulation and pathogen defense by food products shows that fungal beta-glucans could play a role in supporting and maintaining health and, thus, can be seen as a good health-promoting substance from food, which could mean that this effect may also be claimed if approved. In addition to these developments related to food uses of beta-glucan-containing supplements, beta-glucans could also hold a novel position in Western medicine as the concept of trained immunity is relatively new and has not been investigated to a large extent. These innovative concepts, together with the emerging success of modern immunological and biotechnological methods, suggest that fungal glucans may play a promising role in both perspectives, and that there are possibilities for traditional medicine to provide an immunological application in both medicine and nutrition.

Effect of exercise on upper respiratory tract infection in elite runners

BACKGROUND

Since it was assumed that exercise might be a risk factor for upper respiratory tract infection (URTI), the frequency, severity and duration of URTI were assessed in female elite runners compared with matched sedentary group.

METHODS

A group of elite runners (N.=20) and one of sedentary subjects (N.=20) were selected and matched one by one for their age, nutritional state, their place of living and somewhat genetic factors. These groups were observed for any signs and symptoms of upper respiratory illnesses, during 2.5 cold months of the year.

RESULTS

Although the mean number of the illnesses in elite athletes (1.0±0.8) was slightly lower than the control people (1.4±0.8); there was not any statistically significant difference between them (P>0.05). Furthermore, the mean days of disease (5.4±3.8 in elite athletes vs. 5.6±3.0 in control group) showed no significant statistical difference (P>0.05). Even though elite athletes showed no severe cases of the disease, no significant difference was observed between the two groups (P>0.05).

CONCLUSIONS

Elite athletes are not at greater risk for URTI and this may be due to the suitable physiological status of athletes or attributed to" repeated bout effect" phenomenon.

HNP-1 and HBD-1 as Biomarkers for the Immune Systems of Elite Basketball Athletes

Acute or strenuous exercise is sometimes related to upper respiratory tract infections in athletes. Practicing intense and regular exercise can lead to incorrect activation of the immune system, causing athletes to be excluded from training programs and competitions. Defensins are small antimicrobial peptides that are part of the innate immune system and dynamically involved in several biological activities. In this study, we highlight the role of human defensins in competitive basketball athletes. In particular, we consider the behavior of alpha- and beta-defensins together with white blood cells in a cohort of players. Moreover, we focus our attention on cortisol, a physiological indicator of stress, and testosterone, both of which are human hormones involved in muscle metabolism. The free-testosterone/cortisol ratio is considered to be an indicator of overtraining among athletes. This paper provides an up-to-date information of the role of human defensins as self-defense molecules during a continuous stressor such as long-term exercise, and it recognizes them as potential markers of infection.

The Effect of One Bout of Intensive Judo Exercise on Select Hematological and Immunological Parameters in Adolescent Elite Judo Athletes

Background: Exercise-related studies do not agree on changes in blood parameters regarding anemia and serum immunoglobulin concentration as adaptive immunity. Objectives: The current study aimed to investigate exercise-induced variations in hematological and immunological parameters in response to one bout of intensive judo exercise in adolescent elite judoka. Methods: Venipuncture was performed on ten adolescent male Iranian elite judoka (age: 15.60 ± 0.69 years; body mass index: 24.15 ± 2.80 kg/m2) before and immediately after one bout of intensive judo protocol. Erythrocyte variables [red blood cell count (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular volume (MCV), red distribution width (RDW), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC)], platelets variables [platelet count (PLT), platelet distribution width (PDW), mean platelet volume (MPV), plateletcrit (PCT)], cellular immune variables [white blood cell (WBC), neutrophil (NEU), lymphocyte (LYM)], and humoral immune variables (IgM, IgA, IgG, IgE) were measured. Data were analyzed using Wilcoxon and paired-samples t-test, and P < 0.05 was considered significant. Results: After the plasma volume was corrected using the Dill and Costill equation, the results showed that RBC, HGB, HCT, MCHC, IgA, and IgM decreased significantly immediately after exercise. However, MCH, RDW, PLT, PDW, MPV, PCT, WBC, LYM, NEU, IgG, and IgE did not change significantly. Conclusions: According to the findings, it can be concluded that intensive judo exercise results in transient anemia and suppression of humoral immune response among adolescent elite judoka.

Asthma and exercise-induced respiratory disorders in athletes. The position paper of the Polish Society of Allergology and Polish Society of Sports Medicine

Exercise-induced respiratory symptoms describe acute airway narrowing that occurs as a result of exercise. It includes exercise-induced bronchoconstriction (EIB) and exercise-induced asthma (EIA) issues. To provide clinicians with practical guidelines, a multidisciplinary panel of stakeholders was convened to review the pathogenesis of EIB/EIA and to develop evidence-based guidelines for the diagnosis and treatment. Recommendations for the diagnosis and treatment of EIB were developed. High-intensity exercise in polluted environment (cold air, humidity, contamination, allergens) may increase the risk of EIB and asthma symptoms in athletes. Diagnostic procedures should include history taking, physical examination, atopy assessment and functional tests of the respiratory system. A strong recommendation was made for regular use of inhaled glucocorticosteroids and avoidance of short-acting β₂-agonists as the only treatment. The treatment of asthma in athletes should always take into account current anti-doping regulations. This position paper reflects the currently available evidence.

Sideline Management of Nonmusculoskeletal Injuries by the Orthopaedic Team Physician

Although recognized as the most well-trained providers to address musculoskeletal injuries, many orthopaedic surgeons do not routinely treat patients with nonmusculoskeletal issues in their clinical practice. Nonetheless, when serving as a team physician, an orthopaedic surgeon may need to initiate management of or manage many nonmusculoskeletal issues. Knowing how to accurately diagnose and initiate management of sports-related medical and surgical conditions is an important facet of being an orthopaedic team physician. Common systems that may be involved include the cerebral/neurologic, ocular, dental, respiratory/pulmonary, cardiac, abdominal, and genitourinary systems. Each of these systems has specific pathologic processes and risks related to athletic or sporting participation. Orthopaedic team physicians must have a baseline familiarity with the most common nonmusculoskeletal issues to provide comprehensive quality care to athletes and patients.

The influence of sleep and training load on illness in nationally competitive male Australian Football athletes: A cohort study over one season

OBJECTIVES

To determine the incidence of illness, and identify the relationship between sleep, training load and illness in nationally competitive Australian football athletes. Second, to assess multivariate effect between training load and/or sleep variables.

DESIGN

Cohort study.

METHODS

Retrospective analyses of prospectively collected cohort data were conducted on forty-four male athletes over a 46-week season. The primary outcome was illness incidence, recorded daily by medical doctors. Independent variables were acute, chronic and acute:chronic ratios of: sleep quality, sleep quantity, internal training load and external training load defined as: total running distance, high speed running distance and sprint distance. Generalised estimating equations using Poisson (count) models were fit to examine both univariate and multivariate associations between independent variables and illness incidence.

RESULTS

67 incidences of illness were recorded, with an incidence rate of 11 illnesses per 1000 running hours. Univariate analysis showed acute and chronic sleep hours and quality, as well as acute sprint and total running distance to be significantly associated with illness. Multivariate analysis identified that only acute sleep quantity was significantly, negatively associated with illness incidence (OR 0.49, CI 0.25-0.94) once all univariate significant variables were controlled for. There was no relationship between external training load and illness when sleep metrics were controlled for.

CONCLUSIONS

In a cohort of Australian football athletes, whose load was well monitored, reduced sleep quantity was associated with increased incidence of illness within the next 7 days. Monitoring sleep parameters may assist in identifying individuals at risk of illness.

Micronutrient Supplementation does not Change Complement System Response to Heavy Training

We aimed to examine the micronutrient supplementation effect on complement system activity after heavy training. 24 male firefighters were randomly divided into supplemented and placebo groups, and tested for immunology-related parameters using venous blood samples in the fasting state pre- and post-5 weeks of nutritional supplementation. C3 and C4 complement components were determined in a nephelometer from immune complexes formed through specific human antisera and total haemolytic complement activity (CH100) was determined by enzyme immunoassay. Differences between pre- and post-supplementation were observed only for CH100 on placebo group (p=0.004; mean diff −26.92; 95%CI −43.58 to −10.25) and no interaction, treatment or time effects were observed for C3 and C4. Although interaction accounted for 8.8% of the total variance in CH100 (with time effect pre- vs post-accounting for 19.5% of the total variance), the treatment effect (supplemented vs placebo) was not significant. The absence of effects on the complement system response to supplementation during heavy training could be justified by the fact that: (i) nutritional supplements do not improve humoral innate immunity in well-fed subjects; (ii) selected supplements unlikely improve the innate immune system in situations of adequate nutritional status; and/or (iii) selected doses of supplementation were not sufficient to elicit immune changes.