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Sport, Exercise, and the Common Cold
Abstract
Upper respiratory illness may cause more disability among athletes than all other diseases combined. This paper presents the essential epidemiology, risks of infection, and transmission features of upper respiratory illness. Those who provide health care for athletes must understand the subsequent implications of an upper respiratory illness on sport performance and should be familiar with participation and clinical management guidelines for athletes with an upper respiratory illness. The literature suggests that regular, rigorous exercise increases both the incidence and severity of upper respiratory illness, yet the immune system appears to have a distinct level at which moderate exercise promotes optimum health. Although research indicates that upper respiratory illness infections are surprisingly reluctant transmitters, upper respiratory illness transmission may escalate during winter sports seasons. The impact of upper respiratory illness on selected pulmonary, cardiac, and skeletal muscle functions may lead to illness complications in athletes, and sport performance during illness may also decline. Athletes should monitor symptoms, adjust training schedules, and rest during an upper respiratory illness.
... It has been well established that the most common acute illnesses affecting athletes of most sporting codes are upper respiratory tract (URT) illnesses, followed by acute gastrointestinal diseases. [1][2][3][4][5][6][7][8][9][10][11][12] It has also been documented that during periods of highintensity, prolonged training or increased competition 'load', there is an amplified risk of subclinical immunological changes that may increase the risk of symptomatology or specific diagnosis of acute illness. 13 14 Similarly, a single high intensity and prolonged duration exercise session is associated with decreased immunity, which can last from 3 to 72 hours, and this period is referred to as the 'open window' period where an athlete is particularly vulnerable to contract an acute illness. ...
... 13 14 Similarly, a single high intensity and prolonged duration exercise session is associated with decreased immunity, which can last from 3 to 72 hours, and this period is referred to as the 'open window' period where an athlete is particularly vulnerable to contract an acute illness. [15][16][17][18][19] Acute illness is a significant health burden to the athlete 20 and can result in: (1) a reduction in exercise performance, 11 (2) an interruption to training, (3) missing an important international competition and (4) increase the risk of serious medical complications and even sudden death during strenuous exercise. 11 15 16 21 22 It has also been documented that a decrease in exercise performance after full clinical recovery from a URT illness can last for 2-4 days. ...
... [15][16][17][18][19] Acute illness is a significant health burden to the athlete 20 and can result in: (1) a reduction in exercise performance, 11 (2) an interruption to training, (3) missing an important international competition and (4) increase the risk of serious medical complications and even sudden death during strenuous exercise. 11 15 16 21 22 It has also been documented that a decrease in exercise performance after full clinical recovery from a URT illness can last for 2-4 days. 15 In runners participating in endurance events, such as marathons and ultramarathons, there is an increased risk of developing a URT illness in the period after the race. ...
Background Data on the prevalence of acute illness in the period prior to a distance running race are limited. Currently, the presence of systemic symptoms (failed ‘neck check’) is used to advise athletes on participation.
Aim To determine (1) the period prevalence of pre-race acute illness symptoms before a distance running event, (2) if symptomatic runners receiving educational material on acute illness did not start (DNS) the race and (3) if symptomatic runners who chose to start the race, did not finish (DNF) the race.
Methods 7031 runners completed an online pre-race acute illness questionnaire in the 3–5 day period prior to a race. Symptomatic runners received educational information on exercise and acute illness. Runners were followed prospectively to determine DNS and DNF risk.
Results 1338 runners (19.0%) reporting symptoms (7.5% reporting systemic symptoms—failed ‘neck check’) and receiving educational information had a higher DNS frequency (11.0%) compared to controls (6.6%)(p=0.0002). Symptomatic runners who started the race had a higher DNF frequency (2.1%) compared to controls (1.3%) (p=0.0346), particularly runners with systemic symptoms (2.4%; RR=1.90).
Conclusions In summary, 19% (1 in 5) runners reported pre-race acute illness symptoms, with 7.5% (1 in 13) reporting systemic symptoms. Although runner education reduced the percentage symptomatic race starters, the majority of them still chose to race, resulting in a two times higher risk of not finishing in those with systemic symptoms. Pre-race acute illness symptoms are common; an educational intervention affects an athlete's decision to compete yet most symptomatic runners still competed, and systemic symptoms negatively affect performance, with possible health implications.
... 59 The impact on performance results from muscle wasting, impaired motor coordination, decreased muscle strength, maximal oxygen uptake, and endurance capacity as well as disturbances in muscle enzyme activity and metabolism. 19,60 Fever fosters overheating, increases fluid losses, and disturbs water balance. After a full clinical recovery from an upper respiratory tract infection, a decrease in exercise performance can last for 2 to 4 days. ...
... 20,61 The risk of serious medical complications including sudden death during strenuous exercise is increased by the acute infection. 19,20,[60][61][62] In this study, the total number of 273 vaccinations in 234 athletes resulted in 13 lost training days (0.7%) by 6 athletes (2.2%), whereas 16 athletes (5.9%) had to modify 34 training days (1.7%). Neither the type of vaccine (northern or southern hemisphere) nor the number of vaccinations (1 or 2 during one season) influenced the number of lost or modified training days, but the OD of losing training was 2 times higher after the vaccine for the northern hemisphere. ...
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.
... Common colds, as the most common presentation of upper respiratory illness, seem to be an indication that sport and exercise participation may increase those conditions, depending on the individual's immune system reaction (Weidner & Sevier, 1996). When analysing the risk factors for this problem, we should take into account the frequent changes of microclimatic conditions for PETs as well as the relatively low set point for temperature in sports halls , which may be suitable for highly active subjects, while persons with lower levels of physical activity participation may experience some problems including the increased risk for common colds (Weidner & Sevier, 1996). ...
... Common colds, as the most common presentation of upper respiratory illness, seem to be an indication that sport and exercise participation may increase those conditions, depending on the individual's immune system reaction (Weidner & Sevier, 1996). When analysing the risk factors for this problem, we should take into account the frequent changes of microclimatic conditions for PETs as well as the relatively low set point for temperature in sports halls , which may be suitable for highly active subjects, while persons with lower levels of physical activity participation may experience some problems including the increased risk for common colds (Weidner & Sevier, 1996). ...
Physical education teachers (PETs) are exposed to the same psychological stress factors as teachers of other subjects, but the increased physical load in this subgroup may significantly influence the prevalence of certain health problems. This cross-sectional study was designed to assess the frequency of occupational health problems and to identify the role of some risk factors (age, gender, teaching level) for PETs. A self-administered questionnaire was used to examine this problem among 468 Slovenian PETs. The association between each health problem and the risk factors was analysed with two-way contingency tables, Cramer V and binary logistic regression. During their professional career, lower back pain, voice disorders, common cold and auditory problems are the most frequent health problems in PETs. Aging generally increases the odds ratio (OR) for most occupational health problems (OR between 1.01 and 1.11). Female PETs had significantly higher odds for urinary tract infection, headache, cervical spine disorder, dysphonia and aphonia in comparison with male PETs (OR=3.26, 2.40, 1.94, 1.92 and 1.82, respectively). Primary school PETs had approximately twice as high odds for lower back pain and dysphonia as secondary school teachers (OR=1.83 and 1.82, respectively). In order to maintain working ability, good preparation for work, understanding of the injury risk factors and chronic lesions mechanisms, regular prevention exercises and healthy working environments are required.
... it is of clinical importance to report subcategories of GiTill associated with or without systemic symptoms, because systemic symptoms of acute illness are indicative of more severe illness. 22,23 for example, data from two prospective cohort studies showed that ultra-distance runners reporting systemic symptoms and signs of acute prerace illness had a higher risk of not finishing a race. 24,25 More detailed information on the incidence of illness, the total days of training and gameplay interruptions, and the number of drTp in acute GiTill presenting with or without systemic symptoms, will be of value to team physicians in the management of illness during a tournament, and when planning preventative illness strategies. ...
Background:
Gastrointestinal tract illness (GITill) in rugby players is underreported. The incidence, severity (% time loss illness, days lost per illness) and burden of GITill with/without systemic symptoms and signs in professional South African male rugby players during the Super Rugby tournament (2013-2017) are reported.
Methods:
Team physicians completed daily illness logs of players (N.=537; 1141 player-seasons, 102738 player-days). The incidence (illnesses/1000 player-days, 95% CI), severity (% ≥1-day time-loss; days until return-to-play [DRTP]/single illness [mean: 95% CI]) and illness burden (IB: days lost to illness/1000 player-days) for the subcategories of GITill with/without systemic symptoms and signs (GITill+ss; GITill-ss), and gastroenteritis with/without systemic symptoms and signs (GE+ss; GE-ss) are reported.
Results:
The incidence of all GITill was 1.0 (0.8-1.2). Incidence was similar for GITill+ss 0.6 (0.4-0.8) and GITill-ss 0.4 (0.3-0.5; P=0.0603). Incidence of GE+ss 0.6 (0.4-0.7) was higher than GE-ss 0.3 (0.2-0.4; P=0.0045). GITill caused ≥1-day time-loss in 62% of cases (GE+ss 66.7%; GE-ss 53.6%). GITill caused an average of 1.1 DRTP/single GITill, which was similar for subcategories. IB of GITill+ss was higher than GITill-ss (IB Ratio: 2.1 [1.1-3.9; P=0.0253]). IB for GITill+ss is 2 times higher than GITill-ss (IB Ratio: 2.1 [1.1-3.9]; P=0.0253); and GE+ss >3 times higher than GE-ss (IB Ratio: 3.0 [1.6-5.8]; P=0.0007).
Conclusions:
GITill accounted for 21.9% of all illnesses during the Super Rugby tournament, with >60% of GITill resulting in time-loss. The average DRTP/single illness was 1.1. GITill+ss and GE+ss resulted in higher IB. Targeted interventions to reduce the incidence and severity of GITill+ss and GE+ss should be developed.
... Elite athletes are generally believed to have an increased risk of respiratory viral infections [1][2][3][4][5][6][7][8]. However, there is no virological evidence supporting that view. ...
Upper respiratory tract infections (“common cold”) are the most common acute illnesses in elite athletes. Numerous studies on exercise immunology have proposed that intense exercise may increase susceptibility to respiratory infections. Virological data to support that view are sparse, and several fundamental questions remain. Immunity to respiratory viral infections is highly complex, and there is a lack of evidence that minor short- or long-term alterations in immunity in elite athletes have clinical implications. The degree to which athletes are infected by respiratory viruses is unclear. During major sport events, athletes are at an increased risk of symptomatic infections caused by the same viruses as those in the general population. The symptoms are usually mild and self-limiting. It is anecdotally known that athletes commonly exercise and compete while having a respiratory viral infection; there are no virological studies to suggest that such activity would affect either the illness or the performance. The risk of myocarditis exists. Which simple mitigation procedures are crucial for effective control of seasonal respiratory viral infections is not known.
... 4 Strenuous exercise during acute infection can increase the risk of serious medical complications, including sudden death. 2 5-7 Performance impairments from upper respiratory tract illness may also last for 2-4 days after complete recovery. 2 Infectious illness can reduce muscle strength and impair motor coordination, 7 decrease aerobic and endurance capacity 5 and alter metabolic function 7 during and/or after the infection. ...
Objective
To describe weekly illness prevalence and illness symptoms by sex in youth floorball players during one season.
Design
Prospective cohort study.
Setting
Players who were registered to play community level floorball during the 2017–2018 season (26 weeks) in two provinces in southern Sweden.
Participants
471 youth players aged 12–17 years. Mean (SD) age for 329 male players 13.3 (1.0) years and 142 female players 13.7 (1.5) years.
Primary and secondary outcome measures
Weekly self-reported illness prevalence and illness symptoms according to the 2020 International Olympic Committee’s consensus recommendations.
Results
61% of youth floorball players reported at least one illness week during the season, with an average weekly illness prevalence of 12% (95% CI 10.8% to 12.3%). The prevalence was slightly higher among females (13%, 95% CI 11.6% to 14.3%) than males (11%, 95% CI 9.9% to 11.7%), prevalence rate ratio 1.20 (95% CI 1.05 to 1.37, p=0.009). In total, 49% (53% male, 43% female) of illness reports indicated that the player could not participate in floorball (time loss), with a mean (SD) absence of 2.0 (1.7) days per illness week. Fever (30%), sore throat (16%) and cough (14%) were the most common symptoms. Female players more often reported difficulty in breathing/tight airways and fainting, and male players more often reported coughing, feeling tired/feverish and headache. Illness prevalence was highest in the peak winter months (late January/February) reaching 15%–18% during this period.
Conclusions
Our novel findings of the illness prevalence and symptoms in youth floorball may help direct prevention strategies. Athletes, coaches, parents and support personnel need to be educated about risk mitigation strategies.
Trial registration number
NCT03309904 .
... 4 Strenuous exercise during acute infection can increase the risk of serious medical complications, including sudden death. 2 5-7 Performance impairments from upper respiratory tract illness may also last for 2-4 days after complete recovery. 2 Infectious illness can reduce muscle strength and impair motor coordination, 7 decrease aerobic and endurance capacity 5 and alter metabolic function 7 during and/or after the infection. ...
... Existe un efecto de "supervivencia" para los atletas de élite cuyo sistema inmunitario puede ser entrenado para adaptar y atenuar las respuestas a mayores cargas de trabajo que el público en general (14,28). Además, realizar esfuerzos intensos una vez se cursa una infección, puede prolongar su duración promoviendo una complicación médica más grave (29). ...
Las infecciones de las vías respiratorios altas (IVRA), son debilitantes para el potencial deportivo de los atletas de élite. El ejercicio físico activa múltiples vías moleculares y bioquímicas relacionadas con el sistema inmune, sensibles a influencias nutricionales. Sobre este contexto, la inmunonutrición está adquiriendo una nueva dirección orientada a conseguir el equilibrio inmunológico, contraponiéndose con algunas de las teorías que han sentado las bases de la inmunología del ejercicio durante las últimas décadas. Objetivo. Investigar los aspectos nutricionales que puedan mejorar la respuesta inmunológica en deportistas de elite. Estudiar los posibles beneficios del equilibrio inmunológico para mejorar el rendimiento, analizar los factores nutricionales que contribuyan al equilibrio de la respuesta inmunológica y extrapolar la evidencia actual en recomendaciones prácticas de alimentación/suplementación para mejorar la homeostasis de la respuesta inmunológica en atletas de élite, teniendo en cuenta las limitaciones existentes.Resultados. La evidencia científica apunta que se puede potenciar el equilibrio inmunológico y la respuesta inmune a través de la modificación de factores nutricionales. Dentro de los cuales, la vitamina D, los probióticos, la vitamina C y el cinc son los que cuentan con mayor evidencia. Conclusión. Los avances científicos resultan prometedores y de interés para los atletas de élite, debido a que pueden disminuir la incidencia de IVRA, mejorando el éxito deportivo de los mismos. Se requieren más estudios para su validación y aplicación.
... 6 Thus, it is clear that the available evidence is limited and does not give any insight into the changing risk profiles throughout the year. Acute infective illness can adversely affect performance through a number of physiological changes, including impaired motor coordination and a decrease in muscle strength, 11 as well as a reduction in VO2 max and subsequently endurance capacity, muscle wasting and changes in metabolic function. 12 Evidence from other sports has shown that time lost to illness does affect athletes availability to train and compete, 13 and data from a prospective cohort study show that runners who start an endurance race with systemic symptoms of an acute illness are 2-3 times less likely to complete the race. ...
Objective
The aim of this project was to adapt the English, French, German and Russian versions of the International Olympic Committee ( IOC ) injury and illness surveillance form to be sport-specific for use in biathlon.
Methods
23 medical representatives from 16 of the 55 biathlon federations participated in this project to adapt the form and create disease coding relevant to biathlon. The English version of the IOC injury and illness surveillance form was used as the primary template. Four review rounds were used to develop electronic fillable PDF forms. The changes were then forward translated onto the Russian, French and German forms.
Results
Changes were made to event type to biathlon-specific events. A weekly reporting format was adopted in line with the race week format of World Cup events. Wherever possible, coding replaced free-text format to avoid translation issues. New codes were created to describe the time of injury/illness. A new symptom code was added to reflect the prevalence of respiratory infection: sore throat/cold symptoms. As the number of athletes in a team differs between weeks in the season, an additional question was added to ask for the ‘number of athletes in the team for the week’ and for the season.
Conclusion
This project provides a biathlon-specific injury and illness surveillance form in English, French, German and Russian. This forms the basis for surveillance that will contribute to a greater understanding of the illness and injury rate in elite biathletes and ultimately to enhanced athlete well-being and success in biathlon, and winter sports more generally.
... Runners who reported ongoing or recent illness symptoms (in the last 8-12 days) before an endurance race were more likely to drop out of the event; albeit, ~ 98% of runners did reach the finish line [14]. It is a widely held belief that heavy exertion may protract the course of an ongoing infection [15,16]. Worse still, heavy exertion during, or after incomplete recovery from, a viral infection can result in serious medical complications including myositis, rhabdomyolysis and myopericarditis; the latter of which can cause acute arrhythmias leading to sudden death [17,18]. ...
Respiratory and gastrointestinal infections limit an athlete’s availability to train and compete. To better understand how sick an athlete will become when they have an infection, a paradigm recently adopted from ecological immunology is presented that includes the concepts of immune resistance (the ability to destroy microbes) and immune tolerance (the ability to dampen defence yet control infection at a non-damaging level). This affords a new theoretical perspective on how nutrition may influence athlete immune health; paving the way for focused research efforts on tolerogenic nutritional supplements to reduce the infection burden in athletes. Looking through this new lens clarifies why nutritional supplements targeted at improving immune resistance in athletes show limited benefits: evidence supporting the old paradigm of immune suppression in athletes is lacking. Indeed, there is limited evidence that the dietary practices of athletes suppress immunity, e.g. low-energy availability and train- or sleep-low carbohydrate. It goes without saying, irrespective of the dietary preference (omnivorous, vegetarian), that athletes are recommended to follow a balanced diet to avoid a frank deficiency of a nutrient required for proper immune function. The new theoretical perspective provided sharpens the focus on tolerogenic nutritional supplements shown to reduce the infection burden in athletes, e.g. probiotics, vitamin C and vitamin D. Further research should demonstrate the benefits of candidate tolerogenic supplements to reduce infection in athletes; without blunting training adaptations and without side effects.
... Instead, regular or rigorous exercise increases both the incidence and severity of upper respiratory illness. [56] Other concomitant factors such as nutritional status and other lifestyle factors, may synergically contribute to the incidence of the common cold. ...
People worldwide frequently catch a common cold, which occasionally develops into secondary severe conditions such as pneumonia. However, it is unclear whether predisposition to the common cold is associated with the individual's characteristics including age, body weight, lifestyles, diets, and intestinal functions, besides exposure to a responsible pathogen. We addressed this issue epidemiologically considering many relevant clinical factors.
We reviewed data from a cross-sectional study consisting of 39,524 apparently healthy Japanese aged 40 to 79 years (26,975 men and 12,549 women) who underwent a checkup in 2007. Self-reported predisposition to common cold (SPCC) and relevant clinical conditions and parameters were considered.
We observed no significant difference in most clinical parameters including age, body mass index (BMI), glycated hemoglobin (HbA1c), and prevalence of men and current smokers between subjects with and without SPCC. In univariate analysis, circulating white blood cell (WBC) count and serum alanine-aminotransferase (ALT) were significantly higher in subjects with SPCC than in those without, whereas serum high-density lipoprotein cholesterol (HDL-C) and duration of sleep were lower. In logistic regression analysis after full adjustment for relevant confounding factors, BMI categories except BMI of ≥27.0 kg/m² were significantly associated with SPCC compared with BMI of 23.0 to 24.9 kg/m². Short duration of sleep (≤5 hours), occasional alcohol drinking, and no-exercise were significantly associated with SPCC compared with 7 hours sleep duration, no-drinking alcohol, and low frequent exercise (twice per month), respectively. All gastrointestinal disorders (gastric complaints, constipation, and diarrhea) were independently associated with SPCC. Imbalanced diet and taking a snack were also associated with SPCC in a degree dependent manner. Furthermore, WBC count, serum ALT, and HDL-C (as continuous variables) were associated with SPCC (HDL-C was inversely), whereas no significant association was observed between SPCC and age, smoking, HbA1c, and pharmacotherapy for diabetes, hypertension, and dyslipidemia.
Our results demonstrated that multifactorial conditions and parameters might be simultaneously associated with the predisposition to common cold. Prospective studies including detailed common cold questionnaire and measurements are needed to confirm currently suspected causative and protective factors.
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 to 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 15–65 years 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 (four studies) and pulmonary function (three studies), but minimal effects on cardiorespiratory endurance (seven studies in mild ARinf). Longer‐term detrimental effects of ARinf on sports performance (six 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.
PROSPERO (CRD42020159259)
Objective
To determine the days until return to sport (RTS) after acute respiratory illness (ARill), frequency of time loss after ARill resulting in >1 day lost from training/competition, and symptom duration (days) of ARill in athletes.
Design
Systematic review and meta-analysis.
Data sources
PubMed, EBSCOhost, Web of Science, January 1990–July 2020.
Eligibility criteria
Original research articles published in English on athletes/military recruits (15–65 years) with symptoms/diagnosis of an ARill and reporting any of the following: days until RTS after ARill, frequency (%) of time loss >1 day after ARill or symptom duration (days) of ARill.
Results
767 articles were identified; 54 were included (n=31 065 athletes). 4 studies reported days until RTS (range: 0–8.5 days). Frequency (%) of time loss >1 day after ARill was 20.4% (95% CI 15.3% to 25.4%). The mean symptom duration for all ARill was 7.1 days (95% CI 6.2 to 8.0). Results were similar between subgroups: pathological classification (acute respiratory infection (ARinf) vs undiagnosed ARill), anatomical classification (upper vs general ARill) or diagnostic method of ARinf (symptoms, physical examination, special investigations identifying pathogens).
Conclusions
In 80% of ARill in athletes, no days were lost from training/competition. The mean duration of ARill symptoms in athletes was 7 days. Outcomes were not influenced by pathological or anatomical classification of ARill, or in ARinf diagnosed by various methods. Current data are limited, and future studies with standardised approaches to definitions, diagnostic methods and classifications of ARill are needed to obtain detailed clinical, laboratory and specific pathogen data to inform RTS.
PROSPERO registration number
CRD42020160479.
Introduction
Reliably and accurately establishing injury and illness epidemiology in biathletes will provide insight into seasonal changes, provide potential to better embed innovative prevention strategies and advance sports medicine through the provision of effective healthcare to biathletes. The main objective of the Biathlon Injury and Illness Study (BIIS) is to provide the first comprehensive epidemiological profile of injury and illness in biathlon athletes during two consecutive Biathlon World Cup seasons over 2-years.
Methods
The BIIS study methodology is established in line with the International Olympic Committee (IOC) injury and illness surveillance protocols using a biathlon-specific injury and illness report form. Team medical staff will provide weekly data using injury and illness definitions of any injury or illness that receives medical attention regardless of time loss. Injuries or illness must be diagnosed and reported by a qualified medical professional (eg, team physician, physiotherapist) to ensure accurate and reliable diagnoses. Descriptive statistics will be used to identify the type, body region and nature of the injury or illness and athlete demographics such as age and gender. Summary measures of injury and illnesses per 1000 athlete-days will be calculated whereby the total number of athletes will be multiplied by the number of days in the season to calculate athlete-days.
Ethics and Dissemination
This study has been approved by the Bellbery Human Research Ethics Committee (HREC reference: 2017-10-757). Results will be published irrespective of negative or positive outcomes and disseminated through different platforms to reach a wide range of stakeholders.
Purpose:
To evaluate the relative importance and predictive ability of salivary immunoglobulin A (s-IgA) measures with regards to upper respiratory illness (URI) in youth athletes.
Methods:
Over a 38-week period, 22 youth athletes (age = 16.8 [0.5] y) provided daily symptoms of URI and 15 fortnightly passive drool saliva samples, from which s-IgA concentration and secretion rate were measured. Kernel-smoothed bootstrapping generated a balanced data set with simulated data points. The random forest algorithm was used to evaluate the relative importance (RI) and predictive ability of s-IgA concentration and secretion rate with regards to URI symptoms present on the day of saliva sampling (URIday), within 2 weeks of sampling (URI2wk), and within 4 weeks of sampling (URI4wk).
Results:
The percentage deviation from average healthy s-IgA concentration was the most important feature for URIday (median RI 1.74, interquartile range 1.41-2.07). The average healthy s-IgA secretion rate was the most important feature for URI4wk (median RI 0.94, interquartile range 0.79-1.13). No feature was clearly more important than any other when URI symptoms were identified within 2 weeks of sampling. The values for median area under the curve were 0.68, 0.63, and 0.65 for URIday, URI2wk, and URI4wk, respectively.
Conclusions:
The RI values suggest that the percentage deviation from average healthy s-IgA concentration may be used to evaluate the short-term risk of URI, while the average healthy s-IgA secretion rate may be used to evaluate the long-term risk. However, the results show that neither s-IgA concentration nor secretion rate can be used to accurately predict URI onset within a 4-week window in youth athletes.
La fièvre est un symptôme fréquent dans la population générale dont l'étiologie principale est l'infection. Une importante partie de la population française déclare pratiquer une activité physique régulière. Une récente recommandation du club des cardiologues du sport recommande l'arrêt de la pratique sportive pendant un épisode fébrile et dans les huit jours suivant la défervescence thermique.Il existe peu de recommandations à ce sujet. Une revue exhaustive de la littérature a étéréalisée. Cette dernière retrouve de nombreux risques à pratiquer une activité physique en cas d'infection fébrile et permet d'établir les recommandations suivantes : mesures de prévention de la propagation de toute pathologie infectieuse ; arrêt de la pratique sportive en cas d'épisode fébrile et durant une période d'au moins huit à quinze jours suivant la défervescence thermique ; reprise de l'activité sportive progressive après ce délai ; surveillance régulière de l'athlète tout au long du processus. Il existe deux pathologies pour lesquelles des recommandations plus spécifiques existent : la mononucléose infectieuse et la myocardite
The modern-day athlete participating in elite sports is exposed to high training loads and increasingly saturated competition calendar. Emerging evidence indicates that inappropriate load management is a significant risk factor for acute illness and the overtraining syndrome. The IOC convened an expert group to review the scientific evidence for the relationship of load—including rapid changes in training and competition load, competition calendar congestion, psychological load and travel—and health outcomes in sport. This paper summarises the results linking load to risk of illness and overtraining in athletes, and provides athletes, coaches and support staff with practical guidelines for appropriate load management to reduce the risk of illness and overtraining in sport. These include guidelines for prescription of training and competition load, as well as for monitoring of training, competition and psychological load, athlete well-being and illness. In the process, urgent research priorities were identified.
Athletes participating in elite sports are exposed to high training loads and increasingly saturated competition calendars. Emerging evidence indicates that poor load management is a major risk factor for injury. The International Olympic Committee convened an expert group to review the scientific evidence for the relationship of load (defined broadly to include rapid changes in training and competition load, competition calendar congestion, psychological load and travel) and health outcomes in sport. We summarise the results linking load to risk of injury in athletes, and provide athletes, coaches and support staff with practical guidelines to manage load in sport. This consensus statement includes guidelines for (1) prescription of training and competition load, as well as for (2) monitoring of training, competition and psychological load, athlete well-being and injury. In the process, we identified research priorities.
Atypical pneumonias can affect young, otherwise healthy individuals who have close contact with one another, such as athletes in team sports. Symptoms, which often progress gradually, may mimic an upper respiratory tract infection. Mycoplasma, chlamydia, and legionella organisms, along with certain viruses, are the usual atypical pneumonia agents, and antimicrobial therapies are recommended. Because complications, though rare, can be protracted, affect athletic performance, and result in sudden death, return-to-play guidelines should be cautious and patient- and sport-specific.
An epidemiologic study of Los Angeles Marathon (LAM) applicants was conducted to investigate the relationship between self-reported infectious episodes (IE), training data, and LAM participation. Eight days before the LAM, 4926 of 12,200 applicants were randomly selected, and sent a pilot-tested four page questionnaire, which was received 7 days after the LAM. The 2311 respondents were found to be 2.0 yr older and 7.6 min faster than other LAM finishers (p less than .01). Univariate and multivariate analyses (logistic regression) were conducted to test the relationship between IE and km/wk of running (6 total categories). The final model tested controlled for age, marital status, reported sickness in other members of the runner's home, perceived feelings of stress in response to personal training regimens, and the suppressive effect of sickness on regular training. In runners training greater than or equal to 97 vs less than 32 km/wk, the odds ratio (OR) for IE during the 2 month period prior to the LAM was 2.0 (95% confidence interval (CI) 1.2-3.4). A test for trend showed an increase in OR with increase in km/wk category (p = .04) which was largely explained by the increased odds of reported sickness in the greater than or equal to 97 km/wk category. Of the 1828 LAM participants without IE before the LAM, 236 (12.9%) reported IE during the week following the LAM vs 3 of 134 (2.2%) similarly experienced runners who did not participate, OR = 5.9 (95% CI 1.9-18.8). These data suggest that runners may experience increased odds for IE during heavy training or following a marathon race.
With the expanding knowledge of rhinovirus transmission and rhinovirus chemistry, the outlook for control of infections with these agents has brightened considerably. Although rhinoviruses are probably the world's leading cause of respiratory illness, they are surprisingly reluctant transmitters, infecting only about 50% of susceptibles in family-like settings. Current research suggests that rhinoviruses are spread chiefly by aerosol, rather than by fomites or personal contact. It has been possible to interrupt rhinovirus transmission completely by careful use of virucidal facial tissues, which, presumably, smothered aerosols generated by coughing, sneezing and nose blowing. Accordingly, it may be feasible to control rhinovirus (and perhaps other virus) dissemination by appropriate air handling and filtration systems in combination with careful nasal sanitation. Anti-rhinovirus drug development is also moving forward. Although there are over 100 rhinovirus serotypes, it has been found that most rhinoviruses attach to a single cell receptor by a single binding site on the virus. Also, the structure of the rhinovirus capsid is now known at the atomic level. These two pieces of knowledge about basic viral architecture appear to open new vistas for reasoned synthesis of antiviral drugs, and some promising compounds are now under investigation. Even interferon has been demonstrated useful in a family setting. On several research fronts, there are good grounds for optimism about control of rhinovirus colds.
Rhinovirus infections may spread by aerosol, direct contact, or indirect contact involving environmental objects. We examined
aerosol and indirect contact in transmission of rhinovirus type 16 colds between laboratory-infected men (donors) and susceptible
men (recipients) who played cards together for 12 hr. In three experiments the infection rate of restrained recipients (10
[56%] of 18), who could not touch their faces and could only have been infected by aerosols, and that of unrestrained recipients
(12 [67%] of 18), who could have been infected by aerosol, by direct contact, or by indirect fomite contact, was not significantly
different (χ2 = 0.468, P = .494). In a fourth experiment, transmission via fomites heavily used for 12 hr by eight donors wasthe only possible route
of spread, and no transmissions occurred among 12 recipients (P < .001 by two-tailed Fisher's exact test). These results suggest that contrary to current opinion, rhinovirus transmission,
at least in adults, occurs chiefly by the aerosol route.
Rhinovirus was recovered from the fingers of 16 of 38 volunteers and others, who were swabbed during the acute stages of their colds. Very low titres of virus were also recovered from 6 of 40 objects recently handled by infected volunteers, but not from the fingers of 18 non-infected subjects whose flat-mates were shedding virus. When rhinovirus from nasal secretions was dried on skin or other surfaces during laboratory experiments, approximately 40–99 % of infectivity was lost. Virus could be transferred from surface to surface by rubbing, the transfer being more efficient if it was carried out while the inoculum was still damp.
Volunteers could infect themselves if a moderately heavy dose (88 TCD50) of virus was inoculated on the finger and then rubbed into the conjunctiva or nostril, especially if the inoculum was still damp. From estimates of virus titres in nasal washings and on fingers, and of amounts transferred by rubbing, it was concluded that spread of colds is unlikely to occur via objects contaminated by the hands of the virus-shedder, but that a recipient might pick up enough virus on his fingers by direct contact with heavily infected skin or secretions to constitute a risk of self-inoculation via the conjunctiva or nostril.
Communicability of rhinovirus type 16 or type 55 was studied in 24 childless couples; one partner (the donor) was infected
with laboratory-grown virus. Initially, both partners lacked antibody to the challenge agent. Rates of transmission between
partners were 41% and 33% for type 16 and type 55, respectively. These rates are similar to those determined in epidemiologic
studies of natural rhinovirus infection. Although the mucosa of the anterior nares was shown to be highly susceptible to infection
(less than one 50% tissue culture infective dose [TCID50]), transmission rarely occurred unless (1) at least 1,000 TCID50 of virus was recovered from the donor's nasal washing, (2) the donor had virus on his hands and anterior nares, (3) he was at least moderately symptomatic, and (4) he spent many hours with his spouse. Since person-to-person transfer of rhinovirus was so dependent upon time spent together
and shedding of large amounts of virus by the donor, it seems possible that the chain of infection could be interrupted by
environmental manipulation.
The effect on skeletal muscle of acute viral and mycoplasma infections in thirteen men of ages ranging between 20-42 years has been studied. Comparisons are made with eight healthy men in the age group 22-29 years who were confined to bed for periods of time of lengths similar to the confinement to bed of the patients. Muscle samples were taken from the thigh. Glyceraldehyde-3-phosphate (triosephosphate) dehydrogenase (TPD), lactate dehydrogenase (LDH), citrate synthetase (CS) and cytochrome oxidase (cytox) activities were measured and the ultrastructure of the muscle specimens was studied by electron microscopy. Immobilization of the healthy persons induced decreased activities of CS, but those of TPD, LDH and cytox remained unaffected. Return to normal life restored the CS activity. The activities of the four enzymes were lower in the patients than in the healthy subjects after immobilization. During normal life, the activities slowly rose to levels as those seen in the healthy subjects. In connection with the acute disease, focal ultrastructural changes within the muscle were found. The changes were similar to those reported to occur in other, more specific muscle diseases.
The effects of experimentally induced rhinovirus and mycoplasmal respiratory tract infections on the pulmonary function of healthy, young, adult volunteers were investigated prospectively. Before inoculation, 12 volunteers were completely normal, whereas 9 had increased frequency dependence of compliance as their only abnormality of pulmonary function. Rhinovirus infection was induced in 8 of the completely normal volunteers, and 5 developed increased frequency dependence of compliance at the time of illness. These changes returned toward normal during the following 2 weeks and were not associated with concomitant changes in any other parameter of pulmonary function, including "closing volume". Three subjects with increased frequency dependence of compliance as their only abnormality before rhinovirus infection developed no significant change in dynamic compliance or any other abnormality in pulmonary function after infection. No changes in pulmonary function were detected in 3 volunteers with experimentally induced mycoplasmal infection. These finding suggest that although rhinovirus infections are associated primarily with upper respiratory illness, they can produce transient peripheral airway abnormalities in previously normal young adults; however, closing volumes, as well as routine pulmonary function studies, may not detect these changes.
Rhinovirus was transmitted from experimentally infected volunteers (donors) to susceptible recipients and the efficiencies of spread by hand-to-hand contact and large- and small-particle aerosols compared. Transmission of infection was very efficient by the hand route: 11 of 15 hand-contact exposures initiated infection, compared with one of 12 large-particle (P less than 0.005) and none of 10 small-particle (P less than 0.005) exposures. Rhinovirus was present in nine of 18 (50%) nasal swab specimens, 28 of 43 (65%) hand rinses, and seven of 18 (39%) saliva specimens of donors; geometric mean titers of positive specimens were 10(1.5), 10(1.4), and 10(1.2) tissue culture infectious dose 50/ml (TCID 50/ml), respectively. Rhinovirus was present in 20 of 43 (46%) recipient hand rinses, with a geometric mean titer of 10(1.4)TCID50/ml. Virus on donors' hands was transferred to recipients' fingers during 20 of 28 (71%) 10-second hand-contact exposures. These findings support the concept that hand contact/self-inoculation may be an important natural route of rhinovirus transmission.
Changes in pulmonary function due to naturally occurring respiratory tract infection were examinated in 26 normal healthy volunteers during a period of 6 months. Forced expiratory maneuvers in each volunteer were recorded at 2-wk intervals throughout the study and daily during illness. Significant impairment of peak expiratory flow rate, forced vital capacity, forced expiratory volume in one second, and maximal mid-expiratory flow rate at 50% of the vital capacity was observed during infection, whereas changes in the maximal expiratory flow rate at 75% of vital capacity were nonsignificant. From these results, we conclude that large airways are certainly affected during uncomplicated respiratory infections in normal healthy persons and from the changes observed in FVC we suggest that more widespread involvement of the small airways may occur.
The effect of a heavy (marathon, 2.5 hr) and moderate (35 min of running) sport stress on the number and function of lymphocytes, and on the plasma cortisol and leucocyte levels was investigated. Marathon running had a profound effect on the lymphocytes. Though the total number of lymphocytes did not change, their responsiveness to PHA and Con A, especially to PPD, was clearly depressed. The suppression of lymphocyte transformation was transient, the recovery occurring in 24 hr. The marathon running had no effect on antibody-forming capacity when the antigen was given immediately after the performance of the marathon, i.e. at the time when the response of lymphocytes to PHA, Con A and PPD stimulation was impaired. A clear-cut granulocytosis and elevation of plasma cortisol was seen in all the marathon runners. The 35 min of running also resulted in granulocytosis and an increase of plasma cortisol, but it did not cause any impairment of the lymphocyte function.
EACH quadrennium, the officers and Board of Directors of the United States Olympic Committee appoint a Games Preparation Committee, Concerned with organizing the total team effort for the Olympic Games. This Committee is the supervisory group for all US Olympic Committee activities at the Games and is made up of chairmen of the following sub-committees: Team Services, Apparel, Supplies and Equipment, Food and Housing, Medical Advisory, Ticket Services, and Transportation.
The Medical Advisory Committee selects the medical personnel who will travel with and provide medical care for the athletes and officials of the US Olympic team at the Games. This Medical Advisory Committee also surveys the medical environment at the site of the Games, arranges for the medical supplies and equipment, and has supervisory function at the Games. Selections for the Medical and Training Services unit are made from a pool of applicants, some of whom, because of their knowledge
Methods of examining immune function include a charting of susceptibility to infections, differential blood counts or lymphocyte counts, and measures of cell proliferation and immunoglobulin synthesis in response to external mitogens. The reported acute response to exercise is transient and quite variable, depending upon the type of exercise, the immunological methodology used, the intensity of effort relative to the fitness of the individual, and the timing of observation. A leucocytosis, a granulocytosis, a small lymphocytosis, and a decrease in the proportion of T to B cells reflect mainly changes of blood volume, demargination, and migration of cells. Lymphocyte subsets show a decreased helper/suppressor cell ratio and an increase of natural killer cells. Because of the lymphocytosis, mitogens induce an increased overall cell proliferation, but proliferation for a given number of cells is decreased. Prolonged exercise leads to a decrease of serum and salivary immunoglobulin levels. Soluble factors such as interleukin-1 and interferon are increased by a bout of exercise. Cross-sectional comparisons and training experiments suggest that under resting conditions well-conditioned individuals show some lymphocytosis, increased natural killer cell activity, higher levels of interleukin-1, and possibly an enhanced reaction to mitogens. Moderate training does not greatly change exercise responses at a given fraction of maximal effort. Excessive training suppresses immune function, but the changes are small, variable, and thus difficult to relate to overtraining. Moreover, because of their transient nature, they have only a limited influence upon the risks of infection or cancer.
Recent research studies and other evidence suggest that although moderate exercise is good for the immune system, the demanding training programs of many top athletes may suppress the immune system and thereby increase susceptibility to infections. A number of top athletes have suffered from unusual infections normally associated with immune deficiency, and immune abnormalities have been demonstrated in resting samples from top athletes.
Studies from several exercise laboratories have shown that after a single exhausting exercise session there is temporary immune depression, with marked changes in numbers and functional capacities of lymphocytes. These changes, which last for up to several hours, are seen in athletes and untrained individuals.
In several studies in the United States, students who were very active in sports have been shown to be more susceptible to infections than their less active colleagues. Exercising hard during the incubation phase of an infection can increase the severity of the illness. This article examines the evidence, discusses possible mechanisms, and considers the implications.
Immune cells produce factors considered earlier to be distinctively neural in origin, and they also respond to a wide range of neuromediators. Inversely, neural cells respond to stimulation by immunological mediators and generate immune factors. Subsets of receptors for structurally diverse mediators have been found in both systems. The molecular and cellular characteristics of neuroimmune responses suggest that some elements of each system are uniquely sensitive to influences of the other. This chapter explores new findings in several areas of neuroirnmunology. The specificity of T cell receptors for neural antigens, which elicit inflammatory demyelinating reactions in the central nervous system, has been established recently and may represent a useful focus for therapy of autoimmune disorders. Experimental autoimmune encephalomyelitis (EAE) is the predominant model of cellular immune diseases of the central nervous system, in which neural tissue invasion by lymphocytes leads to demyelination and paralysis. CD4+ T helper (TH) cells specific for myelin basic protein (MBP) are the primary mediators of this disease in rats and mice. Many types of neural cells express a range of antigens and respond functionally to mediators from the immune system. The patterns of neural responses observed may be considered to be grouped into four categories, based on the chemical nature of the immunological signal, the time course of the neural response, and whether the effect is neurally restricted or involves other systems. The first two categories encompass the effects of immunologically derived cytokines on neural cell growth, survival, and differentiation that are either direct or the result of alterations in the generation or reception of a neurally derived cytokine. The immunologically specific variants of neuropeptide mediators and receptors for neuropeptides provide for the restriction of responses to the immune system, as well as for opportunities for immunological interactions with the nervous system.
We examined illness patterns in a cohort of 530 male and female runners who completed a monthly log for 12 months. The average number of upper respiratory tract infections (URTIs) per person per year for the cohort was 1.2. An upper respiratory tract infection was indicated by the report of any of the following symptoms; runny nose, sore throat, or cough. Using a multiple logistic regression model, the following factors were found to be associated with having one or more URTIs in the follow-up period: living alone (odds ratio = 2.27, 95% CI = 1.01, 5.09), running mileage (486-865 miles, odds ratio = 2.00, 95% CI = 1.01, 2.78; 866-1388 miles, odds ratio = 3.50, 95% CI = 1.52, 4.44; greater than 1388 miles, odds ratio = 2.96, 95% CI = 1.30, 3.68), body mass index greater than the 75th percentile (odds ratio = 0.58, 95% CI = 0.35, 0.94), and male gender (odds ratio = 0.14, 95% CI = 0.03, 0.68). A significant interaction was found to exist between gender and alcohol use, with the association between alcohol use and upper respiratory tract infections being positive in males and negative in females. These results suggest that running dosage (mileage) is a significant risk factor for upper respiratory tract infections in this group of exercisers.
Various researchers have implied that regular and moderate exercise training may improve the ability of the immune system to protect the host from infection. In contrast, acute, maximal, and exhaustive exercise may have negative effects of the immune system. This study compared the incidence of infectious episodes in 273 runners during a two month training period prior to a 5 K, 10 K, or half-marathon race. In addition, the effect of the race experience on infectious episodes was studied. Twenty-five percent of the runners training more than 15 miles per week reported at least one infectious episode as compared with 34.3% of runners training less than 15 miles per week (p = 0.09). Only 6.8% of the runners preparing for the half-marathon race reported becoming sick with the flu versus 17.9% of the 5 K and 10 K runners (p = 0.067). During the week following the roadrace, runners did not report an increase in infectious episodes as compared to the week prior to the race. These trends suggest that runners with a more serious commitment to regular exercise may experience less infectious episodes than recreational runners because of both direct and indirect affects on immunosurveillance. In addition, the stressful race experience does not appear to increase risk of acquiring an acute respiratory infection.
On decrit l'utilisation avec succes d'acide citrique comme rhinovirucide incorpore dans un mouchoir en papier et l'interruption complete de la transmission de R 16 parmi les participants d'un jeu de poker de 12 heures dans lequel on a utilise des mouchoirs en papier renfermant de l'acide citrique et d'autres virucides
The recent Olympic Games in Seoul featured most of the world's best athletes. To compete at this level, athletes have to adhere to intensive training schedules, and in this article, Lynn Fitzgerald discusses how such rigorous training induces an immunodeficiency state in some athletes, resulting in an increased susceptibility to infection.
The effects of cortisol and adrenaline on natural killer (NK) cell activity and the distribution of circulating lymphocyte subpopulations were studied in twenty volunteers, using a continuous intravenous infusion pattern to simulate some of the hormonal changes induced by major surgery. The participants were allocated to receive either cortisol for 5 h, adrenaline for 1 h, cortisol for 5 h with simultaneous adrenaline during the last hour, or placebo for 5 h. Cortisol induced leucocytosis, neutrophilia, and lymphopenia with marked reduction in the number of T-lymphocyte subsets (OKT3+, OKT4+, and OKT8+ cells). No changes were induced in the activity or number of NK (Leu 11+) cells. Adrenaline produced an instantaneous increase in NK-cell activity accompanied by a selective increase in circulating NK cells. Significant leucocytosis, lymphocytosis and neutrophilia occurred. All measurements returned to preinfusion levels within 15 min after completing infusion. The effects of simultaneous infusion of cortisol and adrenaline were equal to the additive response to the hormones administered separately, except for the leucocytosis, which clearly exceeded this. In the placebo group all measurements remained unchanged. The results confirm the role of adrenaline as a potent stimulator/inducer of NK-cell activity. Adrenaline may be responsible for the increase in NK-cell activity during anaesthesia and major surgery.
Global respiratory muscle strength was studied in 22 normal healthy volunteers during a 4-month winter period. Twelve subjects developed naturally acquired upper respiratory tract infections. Maximal static expiratory and inspiratory mouth pressures fell significantly during these infections. The greatest falls were documented between the third and seventh days of clinical illness. Full recovery occurred by the fourteenth day. We conclude that significant abnormalities of respiratory muscle function can occur during upper respiratory tract infections in otherwise healthy young adults.
A growing number of reports have become available which implicate infectious disease with reduced performance in athletes.
The immune system consists of both nonspecific and specific components geared to control infections. Adaptive immunity functions through both antibody-mediated and cell-mediated compartments to establish and maintain long term immunity to infectious agents. Evidence is accumulating to support the view that physical exercise can lead to modification of the cells of the immune system. However, studies have often not been well designed to control exercise protocols when examining the effects of exercise on the immune system.
Large numbers of peripheral blood lymphocytes are mobilised with exercise and in vitro tests indicate that temporarily these cells may not be capable of responding normally to mitogens. These reactions appear to be influenced by hormones to some degree and there are reports that the cells of the immune system are extremely active biochemically and may depend on products from muscles to maintain their activity.
Specific populations within the circulating leucocyte pool vary significantly with exercise and there is some evidence that the T4/T8 lymphocyte ratio may become significantly reduced. This reduction in ratio may be related to the variable responses to T and B cell mitogens recorded in vitro which overall suggests that a temporary immune suppression may exist following certain training or performance schedules. It is argued that this may lead to a temporary susceptibility to infection and could result from overtraining.
Peritoneal murine macrophages were assayed for their enzyme content and phagocytic activity after physical exercise. An endurance training as well as a single exhaustive exercise bout caused increased enzyme and phagocytic activities. However, a homogeneous activation could not be observed. The exhaustively exercised animals delivered macrophages with the highest levels of activation. Therefore, physical exercise has to be listed among the stimuli with macrophage-activating function. The inconsistency between an activating effect of physical exercise on macrophages and the observation that high-performance athletes suffer more frequently from harmless infectious diseases is discussed.
Viruses are ubiquitous and cause numerous infections in humans. These may vary from asymptomatic infection to severe debilitating illness. Viruses enter the host cells to replicate, using host synthetic mechanisms, and, thus, are resistant to conventional antibiotics. The human body responds to viral infection by synthesising specific antibody which can be used to aid diagnosis. Infectious mononucleosis (glandular fever) commonly affects the 15 to 30 years age group. It may produce severe debility which may last a month or more. Coxsackie virus infection can produce symptoms of the common cold but may also invade heart muscle and produce myocarditis, a potentially serious disease. Other viruses also produce a wide spectrum of disease.
Recent evidence has shown that people undergoing severe mental or physical stress may have reduced immunity to viral infections. There are risks associated with strenuous physical activity during the acute phase of viral infection, and there are reports of sudden death and serious complications occurring in previously fit young adults who undertake vigorous exercise when in the acute phase of a viral illness. Abnormalities of skeletal muscle have been demonstrated in patients with viral infection and this may explain the loss of performance experienced by athletes after upper respiratory tract infection.
As a general rule, for all but mild common colds, it is advised that the athlete avoids hard training for the first month after infection.
Although the goals of studies of neuroimmunology are to elucidate the bases of integrated physiological events, most of the tangible accomplishments have been limited to analyses of the neuroanatomy of organs of immunity, the antigens, receptors, and synthetic pathways shared by the two systems—the interdependence of their development and functional interactions. The effects of behavior as a set of variables that condition neuroimmunological communication have just begun to be explored meaningfully. The neuroanatomical bases for some of the observed immunological effects of central nervous system (CNS) lesions appear to be alterations in specific noradrenergic and peptidergic fibers that end in zones of lymphocytes in thymus, spleen, Peyer's patches, and bone marrow. The development of the thymus in some species also is dependent on the integrity of distinct sections of neural crest and neuroendocrine functions. Chromogranin, a secretory protein marker of neuroendocrine cells, has been demonstrated immunochemically in rodent spleen, lymph nodes, and thymus. This chapter focuses on the peptide mediators generated and recognized by distinct elements of the neuroendocrine–immune network that govern many critical developmental and functional interactions.
The studies were performed on 20 conditioned cyclists and 19 untrained men. At rest absolute and percent number of neutrophils, eosinophils, and monocytes, neutrophil bactericidal activity, and blood plasma β-glucuronidase, acid phosphatase, and lactic dehydrogenase (LDH) activities were similar in sportsmen and untrained men, while neutrophil adherence was lowered in sportsmen.
Maximal physical exercise induced significant rises in absolute numbers of neutrophils and monocytes in both groups. In sportsmen, adherence of neutrophils and monocytes and neutrophil bactericidal activity significantly decreased under the influence of exercise, while neutrophil phagocytic activity did not change. On the other hand, in untrained men, maximal physical exercise did not induce significant changes in neutrophil and monocyte adherence and bactericidal activity of neutrophils, but their phagocytic activity increased. Blood plasma β-glucuronidase, acid phosphatase, and LDH activities increased during exercise in both groups. The changes observed tended to normalize during 2-h recovery. The results obtained suggest that intensive physical exercise tends to depress nonspecific immunity, which may render sportsmen more susceptible to infections.
To study prospectively the effects of a brief febrile viral infection on parameters of muscle and circulatory function, seven volunteers were inoculated with sandfly fever virus and two control subjects with sterile saline. During but not after fever, decreased isometric and dynamic strength and endurance were recorded in various muscles. Impairment could not be explained by altered activities of relevant muscle enzymes in serum or muscle tissue or by altered muscle ultrastructure, but correlated with the severity of perceived symptoms, including myalgia, as rated by each subject. Compared to baseline, cardiac stroke volume was lower during and after fever. During fever, an increased heart rate maintained cardiac output at pre-inoculation values, whereas cardiac output fell in early convalescence. This decrease in cardiac output correlated significantly with the severity of fever. Thus, in brief viral infections a transient impairment of muscle performance capacity is correlated to subjective symptoms such as myalgia, rather than to fever, whereas a decreased cardiac output following such infections seems to be associated with the fever reaction.
RHINOVIRUSES have been associated with 10 to 30 per cent of acute upper respiratory illnesses in several groups of adults.1 2 3 4 5 6 In March, 1963, a study was undertaken to define the etiology and epidemiology of acute respiratory disease in a population of working adults, and the role of a number of viruses was studied initially. Coincident with the beginning of the investigation, improvements in technology occurred that facilitated the isolation of rhinoviruses and shifted emphasis to these agents. During the first three years of the study, the period considered in this report, approximately a quarter of the acute respiratory illnesses were . . .
Effects of common colds on the lower respirary tract were evaluated in 18 healthy adults by comparing each subject's pulmonary function while free of illness with that during a cold. Eight of 24 illnesses studied were associated with rhinovirus infection, and no etiology was detected for the others. No consistent effects on spirometric pulmonary functions were observed; however, the steady state carbon monoxide diffusing capacity at rest decreased during 12 of 14 colds for which data were available. Further analysis indicated that the reduction in diffusing capacity of -4.293 ml per min per mm Hg was statistically significant. The most probable explanation of these findings is the occurrence of bronchiolitis leading to ventilation inhomogeneity but few overt symptoms during common colds in healthy adults. The more prominent lower respiratory manifestations of colds in persons who smoke and/or have chronic bronchitis might result from superimposition of 2 disease processes at the same site.
To the Editor.—
The recent death during a football game of a 28-year-old football player in Detroit was widely reported in the daily press. Autopsy revealed generalized coronary atherosclerosis and a recent intra-arterial thrombus.Earlier this year, McMillan and I edited a monograph which documents the causes of more than 100 cases of unheralded sudden death during exercise (Exercise and Cardiac Death. Basel, Switzerland, Karger, 1971). Unexpected sudden death of athletes due to heart disease is a rare event. It may occur in young as well as in old subjects. The group studied by us is distinguished by the fact that the cardiac diseases had proceeded asymptomatically without impairment of physical fitness. Several of the victims had been outstanding athletes. Among the postmortem findings, coronary atherosclerosis and degenerative changes of the myocardium were the most frequent. Other diagnoses made at autopsy by us as well as other investigators were congenital
Potentially lethal cardiac disease may manifest itself first by the terminal collapse. The preceding natural history of illnesses belonging to the nosological category thus identified is distinguished by the absence of symptoms and by unimpaired physical fitness. The four cases described each represent a diagnostic entity of the kind under reference.
We have previously demonstrated that mitogen responsiveness of mononuclear cells (MNC) from peripheral blood is reduced after a single injection of epinephrine to human subjects. The purpose of the present study was to characterize the relative distributions of MNC subsets after epinephrine administration using monoclonal antibodies and conventional cell markers. The absolute number of circulating MNC increased 64% within 30 min after injection of epinephrine, and returned to baseline by 2 hr. Analysis of MNC subsets revealed that there were no changes in the relative percentages of total T lymphocytes [T3+ cells, or neuraminidase-treated sheep red blood cell rosettes (EN-rosettes)], B lymphocytes (B1+, or cells with surface-bound immunoglobulin), or monocytes (by morphologic criteria) after epinephrine administration. The percentage of inducer T cells (T4+) declined at 30 and 60 min postinjection. Overall, the percentage of suppressor/cytotoxic T cells (T8+) did not change after injection of epinephrine; however, analysis of individual subjects revealed opposing responses of this subset. The T4:T8 ratio was 2.19 before injection, declined to 1.56 at 60 min, then increased to 3.10 2 hr postinjection. The percentage of natural killer/killer cells (HNK-1+) increased from a baseline of 15.5% before epinephrine injection to 29.6% at 30 min postinjection, then declined to 11.4% at 2 hr. Therefore, the administration of physiologic doses of epinephrine results in changes in the relative proportions of lymphocyte subsets in peripheral blood, in addition to reduced mitogen responsiveness as reported previously.
Transfer of experimental rhinovirus infection by an intermediary environmental surface was examined in healthy young adults, in four studies done in 1980--1981, by having recipients handle surfaces previously contaminated by infected donors. Recipients touched their nasal and conjunctival mucosa after touching the surfaces. Five (50%) of 10 recipients developed infection after exposure to virus-contaminated coffee cup handles and nine (56%) of 16 became infected after exposure to contaminated plastic tiles. Spraying of contaminated tiles with a commercially available phenol/alcohol disinfectant reduced (p = 0.003) the rate of recovery of virus from the tiles from 42% (20/47) to 8% (2/26). Similarly, the rate of detection of virus on fingers touching the tiles was reduced (p = 0.001) from 61% (28/46) with unsprayed tiles to 21% (11/53) with sprayed tiles. Fifty-six per cent (9/16) of the recipients exposed on three consecutive days to untreated tiles became infected while 35% (7/20) touching only sprayed tiles became infected with rhinovirus (p = 0.3). These studies indicate that experimental rhinovirus colds can be spread by way of contaminated environmental surfaces and suggest that disinfectant treatment of such surfaces may reduce risk of viral transmission by this route.
Opinions differ as to whether marathon runners have an increased susceptibility to upper respiratory tract (URT) infections after a race. In an attempt to answer this question, we carried out a prospective study of the incidence of symptoms of URT infections in 150 randomly selected runners who took part in the 1982 Two Oceans Marathon in Cape Town, and compared this with the incidence in individually matched controls who did not run. Runners were questioned on the day before and 2 weeks after the race. Symptoms of URT infection occurred in 33.3% of runners compared with 15.3% of controls, and were most common in those who achieved the faster race times. The incidence in slow runners was no greater than that in controls. Faster runners also experienced more musculoskeletal pain during and after the race. These results suggest a relationship between acute stress and susceptibility to URT infections. Impairment of one or more local mucosal or general host defences may account for this effect.
The comparative examination of 91 sportsmen under physical strain of different intensity and 30 healthy adults not active in sport has been made. A decrease in the functional activity of neutrophils in response to increasing physical strain has been revealed, which coincides with a drop in the levels of normal serum and secretory antibodies, immunoglobulins and lysozyme.
Secretory IgA levels were studied in nationally ranked Nordic skiers before and after the national cross-country races held in February 1981. Comparing the skiers with age-matched controls, there was significantly lower level of salivary IgA before the race. Concentrations of IgA decreased further following the competition (50 kn for males; 20 km for females) to very low levels. There also were a significant increase in the percentage of B lymphocytes and a decrease in the null population (non-T, non-B) in the athletes after the race compared with the controls. The mechanism responsible for these changes is unknown, but the low salivary IgA levels may result from depletion of nasal fluid and/or malfunction of the mucosal plasma cells due to a decrease temperature in the mucous membranes. We speculated that a temporary antibody deficiency on the mucosal surface might lead to a susceptibility to acquiring viral and bacterial infections, especially during the interval immediately following strenuous exercise.