Routine exercise alters measures of immunity and the acute phase reaction.

PURPOSE: To expand our understanding of the overall anti-inflammatory nature of routine exercise; we compared resting blood values from adults who habitually undertake frequent, moderate levels of exercise to reference interval values assumed to reflect values largely from non-exercisers. This information would be useful for clinicians interpreting blood tests assessing inflammatory, immune and acute phase responses. METHODS: Blood samples were collected from 119 community adult self-reported routine exercisers (61 males and 58 females aged 18-60 years). Samples were analysed for 20 cellular and non-cellular biomarkers which included 11 immunological and 9 acute phase reactants. These data were compared to reference intervals from the same hospital laboratory that performed the analyses on our participants' samples. Individual analyte values were also compared with participants' self-reported 150 day exercise patterns which included exercise frequency, intensity and duration. RESULTS: In general, mean values for routine exercise participants fell at the lower end of laboratory reference interval for most inflammatory analytes. More than 10 % of participants had numbers of CD19(+), CD8(+) and 16/56(+) NK cells below the low end of the respective reference interval. More than 10 % of observed acute phase reactant values (for C3, haptoglobin and ferritin) were also below the low end of the reference interval. At rest IgM (r = -0.22) and IgG (r = -0.31) values correlated negatively (p < 0.05) with exercise load. CONCLUSIONS: Routine exercise appears to lower resting numbers of a variety of immune cell-types as well as the concentration of several classical acute phase reactants. These wide-ranging systemic effects are presumably adaptive changes, not pathology and collectively confirm the well-reported and clinically important anti-inflammatory effects of exercise.

Effects of probiotic supplementation over 5 months on routine haematology and clinical chemistry measures in healthy active adults.

Use of probiotic-containing foods and probiotic supplements is increasing; however, few studies document safety and tolerability in conjunction with defined clinical end points. This paper reports the effects of 150 days of supplementation with either a single- (Bifidobacterium animalis subsp. lactis Bl-04) or a double-strain (Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis Bi-07) probiotic on routine haematology and clinical chemistry measures in healthy active adults. Pre- to post-intervention changes in laboratory measures were determined and compared between supplement and placebo groups. Overall there were few differences in routine haematology and clinical chemistry measures between supplement and placebo groups post-intervention. Exceptions included plasma calcium (P=0.03) and urea (P=0.015); however, observed changes were small and within assay-specific laboratory reference ranges. These data provide evidence supporting the use of these probiotic supplements over a period of 5 months in healthy active adults without obvious safety or tolerability issues.

The effect of exercise on innate mucosal immunity.

METHODS: The authors conducted a prospective observational study comparing salivary lactoferrin and lysozyme concentration over 5 months (chronic changes) in elite rowers (n=17, mean age 24.3+/-4.0 years) with sedentary individuals (controls) (n=18, mean age=27.2+/-7.1 years) and a graded exercise test to exhaustion (acute changes) with a cohort of elite rowers (n=11, mean age 24.7+/-4.1). RESULTS: Magnitudes of differences and changes were interpreted as a standardised (Cohen's) effect size (ES). Lactoferrin concentration in the observational study was approximately 60% lower in rowers than control subjects at baseline (7.9+/-1.2 microg/ml mean+/-SEM, 19.4+/-5.6 microg/ml, p=0.05, ES=0.68, 'moderate') and at the midpoint of the season (6.4+/-1.4 microg/ml mean +/- SEM, 21.5+/-4.2 microg/ml, p=0.001, ES=0.89, 'moderate'). The concentration of lactoferrin at the end of the study was not statistically significant (p=0.1) between the groups. There was no significant difference between rowers and control subjects in lysozyme concentration during the study. There was a 50% increase in the concentration of lactoferrin (p=0.05, ES=1.04, 'moderate') and a 55% increase in lysozyme (p=0.01, ES=3.0, 'very large') from pre-exercise to exhaustion in the graded exercise session. CONCLUSION: Lower concentrations of these proteins may be indicative of an impairment of innate protection of the upper respiratory tract. Increased salivary lactoferrin and lysozyme concentration following exhaustive exercise may be due to a transient activation response that increases protection in the immediate postexercise period.

Respiratory symptoms and inflammatory responses to Difflam throat-spray intervention in half-marathon runners: a randomised controlled trial.

OBJECTIVE: In this study, the effects of Difflam Forte Anti-inflammatory Throat Spray on the incidence of upper respiratory symptoms (URS) and inflammatory responses after a half-marathon race were investigated. DESIGN AND SETTING: Double-blind placebo-controlled randomised trial conducted in association with a half-marathon event. PARTICIPANTS: 45 well-trained half-marathon runners. INTERVENTIONS: Difflam (n = 25) or placebo (n = 20) throat sprays were self-administered three times daily for 1 week before and 2 weeks after the race. MAIN OUTCOME MEASURES: Self-reported respiratory symptoms; plasma prostaglandin E(2), myeloperoxidase, interleukin (IL) 6, IL8, IL10 and IL1 receptor antagonist (IL1ra) concentrations; and salivary myeloperoxidase and IL6 concentrations. RESULTS: All subjects completed the intervention without reporting any adverse events. The proportion of athletes reporting URS was not substantially different between Difflam (52%) and placebo (56%) groups (p = 0.82). However, symptom severity scores were approximately 29% lower during Difflam treatment (4.7 (7.4) vs 6.6 (9.6)) AU). Post-exercise responses in plasma inflammatory markers did not differ substantially between Difflam and placebo groups. Post-race increases in salivary myeloperoxidase ( approximately 63%; trivial to moderate difference; p = 0.13) and salivary IL6 ( approximately 50%; trivial to moderate difference; p = 0.25) were greater in the Difflam group. CONCLUSIONS: Prophylactic use of the Difflam reduced the severity, but not the frequency, of URS among half-marathon runners. Post-race increases in systemic inflammatory markers were not altered by Difflam use, but markers of local inflammation (salivary myeloperoxidase and IL6) were augmented in the Difflam compared with the placebo group.

Oral administration of the probiotic Lactobacillus fermentum VRI-003 and mucosal immunity in endurance athletes.

OBJECTIVE: To evaluate the ability of a probiotic Lactobacillus fermentum VRI-003 (PCC) to enhance the mucosal immune system of elite athletes. DESIGN AND SETTING: A double-blind, placebo-controlled, crossover trial was conducted over a 4-month period of winter training. PARTICIPANTS; 20 healthy elite male distance runners. INTERVENTIONS: PCC was given at a daily dose of 1.26 x 10(10) as a freeze-dried powder in gelatin capsules. Placebo capsules contained an inert excipient. MAIN OUTCOME MEASURES: Treadmill performance (monthly), mucosal and systemic immunity (monthly), training (daily) and illness (daily) were assessed. Serum cytokine levels, salivary IgA levels and incidence, duration and severity of respiratory tract infections were measured. RESULTS: Subjects reported less than half the number of days of respiratory symptoms during PCC treatment (30 days) compared with placebo (72 days, p<0.001). Illness severity was also lower for episodes occurring during the PCC treatment (p = 0.06). There were no significant differences in the mean change in salivary IgA and IgA1 levels, or in interleukin (IL)4 and IL12 levels, between treatments. However, PCC treatment elicited a twofold (p = 0.07) greater change in whole-blood culture interferon gamma (IFNgamma) compared with placebo. No substantial changes in running performance measures were seen over the study period. CONCLUSIONS: Prophylactic administration of PCC was associated with a substantial reduction in the number of days and severity of respiratory illness in a cohort of highly trained distance runners. Maintenance of IFNgamma levels may be one mechanism underpinning the positive clinical outcomes.

Reversal in fatigued athletes of a defect in interferon gamma secretion after administration of Lactobacillus acidophilus.

BACKGROUND: Fatigue and impaired performance in athletes is well recognised and has been loosely linked to "overtraining". Reduced concentration of IgA in the saliva and increased shedding of Epstein Barr virus (EBV) have been associated with intense training in elite athletes. OBJECTIVE: To determine whether athletes presenting with fatigue and impaired performance had an immune defect relevant to defective containment of EBV infection, and whether a probiotic preparation (Lactobacillus acidophilus) shown to enhance mucosal immunity in animal models could reverse any detected abnormality. RESULTS: The fatigued athletes had clinical characteristics consistent with re-activation of EBV infection and significantly (p = 0.02) less secretion of interferon (IFN) gamma from blood CD4 positive T cells. After one month of daily capsules containing 2 x 10(10) colony forming units of L acidophilus, secretion of IFNgamma from T cells had increased significantly (p = 0.01) to levels found in healthy control athletes. A significant (p = 0.03) increase in salivary IFNgamma concentrations in healthy control athletes after the one month course of L acidophilus demonstrated in man the capacity for this probiotic to enhance the mucosal IFNgamma concentration. CONCLUSION: This is the first evidence of a T cell defect in fatigued athletes, and of its reversal following probiotic therapy.

Characterising the individual performance responses to mild illness in international swimmers.

OBJECTIVES: To determine individual differences in the impact of illness on the change in performance of swimmers in international competitions. METHODS: Subjects were members of the Australian swimming team (33 male and 39 female, aged 15-27 years). Swimmers provided a weekly seven day recall of symptoms of illness during final six weeks of preparations for international competition over a three year period. Swimmers were categorised as either ill (one or more episodes of illness) or healthy. The measure of performances was the international point score. Mean changes in points score were calculated for healthy and ill swimmers between a national championship and an international competition ( approximately 16 weeks later). Likelihoods of substantial effects of illness on an individual's true change in performance (beneficial/trivial/harmful) were estimated from means and standard deviations, assuming a smallest substantial change of 6 points. RESULTS: Illness was reported before international performances by 38% of female and 35% of male swimmers. For female swimmers the change in performance was -3.7 (21.5) points (mean (SD)) with illness and -2.6 (19.0) points when healthy; for male swimmers the changes were -1.4 (17.5) points with illness and 5.6 (13.2) points when healthy. The likelihoods that illness had a substantial beneficial/trivial/harmful effect on performance of an individual swimmer were 32%/31%/37% for female and 17%/31%/52% for male participants (90% confidence limits approximately +/-10% to 20%). CONCLUSIONS: Although mild illness had only a trivial mean effect on female swimmers and a small harmful mean effect on male swimmers, there were substantial chances of benefit and harm for individuals.

In-vivo cell mediated immunity in elite swimmers in response to training.

This study investigated in-vivo cell-mediated immune (CMI) responses in elite swimmers over a 5-month training season, to assess the impact of intense training on changes in T-lymphocyte function. The CMI Multitest was performed early in the season after a period of rest, during peak high-intensity training, and late in the season during the precompetition taper period. The CMI tests were performed at rest prior to a morning training session. There were no significant differences between the swimmers and a control group for any of the seven CMI antigen responses at any of the test points during the season. In the swimmers, there were no significant differences in the number of positive responses to the CMI antigens between the three test points (Friedman's test = 9.6364, p = 0.47) and no significant differences for the CMI cumulative scores (Friedman's test = 11.98, p = 0.29) at each test point. There was no consistent pattern for changes in CMI cumulative scores for individual swimmers over the training season. The findings of this study indicate that, despite reported transient T-lymphocyte immunosuppression immediately after intense exercise, probably associated with acute redistribution and temporary pooling of blood T cell subsets in extremities, the T-lymphocyte function involved in CMI responses is not compromised by extended periods of training at an elite level.

Stress fracture of the clavicle in a young female gymnast.

Stress fractures of the clavicle are rare. This is the report of one such fracture in a 10 year old female gymnast, who presented with a six week history of medial clavicular pain. Radiographs and a computed tomography scan showed an undisplaced fracture through the medial third of the clavicle extending inferiorly to the rhomboid fossa in the inferior aspect of the clavicle. Pathological fracture was excluded by magnetic resonance imaging. The patient was treated conservatively and was able to return to full training eight weeks later.

Mucosal immunity, respiratory illness, and competitive performance in elite swimmers.

PURPOSE: Exercise and training are known to elicit changes in mucosal humoral immunity, but whether these alterations have any impact on competitive performance remains unclear. This investigation examined relationships between salivary immunoglobulin (Ig) concentration, the incidence of respiratory tract illness (RTI), and competitive performance in elite swimmers. METHODS: Forty-one members of the Australian Swimming Team (21 males and 20 females) aged 15-27 yr were monitored during preparations for the 1998 Commonwealth Games. Twenty-five coaches and staff (19 males and 6 females) aged 32-65 yr, serving as "environmental controls," were also monitored. Salivary IgA, IgM, and IgG and albumin concentration (mg.L-1) were measured in both groups in May 1998 and again in August 1998, 17 d before competition. Subjects were categorized as "ill" (at least one RTI) or "healthy". RESULTS: There were no significant changes in salivary IgA, IgM, or IgG concentration in the swimmers between May and August, nor were there any differences between healthy (N = 23) and ill (N = 18) swimmers. There was a significant positive relationship between IgM and performance in the male swimmers (r = 0.85, P < 0.001) but not for any other parameter. There was no significant difference in performance between ill and healthy swimmers (P = 0.11). Gold medal winners (N = 9) had higher IgM levels than other swimmers (N = 32) in May (P = 0.02) and higher IgG in August (P = 0.02). CONCLUSION: These data indicate that a season of training by elite swimmers did not alter salivary immunoglobulin concentrations, and the presence of RTI had no significant impact on competitive performance.

Training strategies to maintain immunocompetence in athletes.

Clinical experience and empirical evidence have led to the modeling of exercise and training as a form of stress on the immune system. Coaches, athletes, and medical personnel are seeking guidelines on ways to reduce the risk of illness that compromises training or competitive performance. The immune system is influenced by a wide range of physical, environmental, psychological, and behavioural factors which, combined with clinical assessment, collectively form the basis of the following intervention strategies: 1) training: careful management of training volume and intensity, variety to overcome training monotony and strain, a periodised approach to increasing loads, and provision of adequate rest and recovery periods; 2) environmental: limiting initial exposure when training or competing in adverse environmental conditions (heat, humidity, altitude, air pollution) and acclimatising where appropriate; 3) psychological: teaching athletes self-management and coping skills and monitoring of athletes' responses to the psychological and psychosocial stresses of high-level training and competition; 4) behavioural: adopting a well-balanced diet with adequate intake of macro- and micro-nutrients, limiting transmission of contagious illnesses by reducing exposure to common infections, airborne pathogens, and physical contact with infected individuals; and 5) clinical considerations: medical screening, pathology testing, immunization and prophylaxis, and routine management of illness-prone athletes. Future experimental studies are required to develop and enhance the effectiveness of these strategies in reducing illness in athletes.

Immune status and respiratory illness for elite swimmers during a 12-week training cycle.

The impact of a 12-week training program by elite swimmers on systemic and mucosal immunity was studied prospectively to examine the relationship between changes in immune parameters and the incidence of respiratory illness. Saliva was collected before and after selected training sessions at 2 weekly intervals. There were significant decreases in salivary IgA (p=0.05) and salivary IgM (p < 0.0001) concentrations after individual training sessions, but no significant changes in salivary IgG or albumin concentrations. Over the 12-week training program there were small but statistically significant increases in pre-exercise concentrations of salivary IgA (p<0.001), IgM (p=0.015) and IgG (p=0.003) and post-exercise salivary IgA (p <0.001). There were no significant trends over the 12 weeks for any class of serum immunoglobulins but a significant fall in NK-cell numbers (p<0.001). There were no associations between serum or salivary immunoglobulin levels or NK-cell numbers and upper respiratory tract illness (URTI) during the 12-week program. The data indicated that despite changes in some immune parameters during this final training program prior to competition there were no associations detected with URTI for this cohort of elite swimmers.

The young athlete.

BACKGROUND: It is very much part of the Australian lifestyle to encourage children and adolescents to participate in sport and exercise. As a result the general practitioner is often presented with injuries in younger patients. OBJECTIVE: This article presents an overview of the growth and development of the musculoskeletal system, and discusses relevant aspects of conditioning and training and the nature of injuries seen in the younger athlete. DISCUSSION: The range of common musculoskeletal problems seen in young children and adolescents is outlined with some recommendations made for an approach to management of the commoner conditions.

Sudden death due to ischaemic heart disease in young aboriginal sportsmen in the Northern Territory, 1982-1996.

OBJECTIVE: To estimate the incidence of sport-related sudden cardiac death due to ischaemic heart disease (IHD) in competitive young Aboriginal sportsmen. SETTING: Northern Territory (NT), 1982-1996. DESIGN: Retrospective case series with cases identified from Australian Bureau of Statistics cause-of-death listings and NT coronial autopsy records. MAIN OUTCOME MEASURES: Circumstances and incidence of sport-related sudden cardiac deaths due to IHD; autopsy findings. RESULTS: Between 1982 and 1996, there were eight sudden cardiac deaths due to IHD and related to sporting activity among Aboriginal sportsmen aged 15-37 years in the NT. Six were associated with games of Australian (rules) football. All occurred in the Top End of the NT in the wet season, and all occurred after the first half, or within an hour of, a game. Four of the players had macrosopic myocardial abnormalities (hypertrophy or previous infarcts) on autopsy. The estimated incidence of IHD-related sudden cardiac death among Aboriginal Australian football players in the NT was 19-24 per 100,000 player-years, compared with 0.54 per 100,000 player-years among Australian rules footballers of similar ages in Victoria. CONCLUSIONS: Incidence of sudden cardiac death attributable to underlying IHD was extremely high among young NT Aboriginal Australian footballers. Prevention will best be achieved by funding culturally appropriate long-term strategies to reduce the incidence of IHD. However, in the short-term, community-controlled programs with education of athletes, heat-stress reduction strategies, and cardiovascular screening should reduce the incidence of sudden cardiac death in sport.

Attention deficit hyperactivity disorder, CNS stimulants and sport.

Attention deficit hyperactivity disorder (ADHD) affects 1 to 10% of children and is characterised by a persistent pattern of inattention and/or hyperactivity/impulsivity. Over one-half of children with ADHD have associated conditions, including learning disabilities, conduct disorders, poor coordination, depression, anxiety, obsessive-compulsive disorders and bipolar disorders. CNS stimulant medication used in the management of ADHD is not permitted for use in competition by the International Olympic Committee (IOC) and this poses a problem for the physicians of patients with ADHD. On the one hand, attention and concentration are improved by stimulant medication and fine motor coordination and balance are improved after methylphenidate administration, but these therapeutic and sport-related benefits are not available to the athlete with ADHD who wishes to compete under IOC rules. It has been suggested that treatment with methylphenidate may be suitable for athletes with ADHD, as cessation of therapy 24 hours before competition is usually adequate to allow drug clearance which should avoid a positive result being returned on drug testing. More research is needed to establish whether stimulant medication for athletes with ADHD provides an unfair advantage in competition.