International SportMed Journal - Volume 4, Issue 3, 2003
Volume 4, Issue 3, 2003
Author Maurice MarsSource: International SportMed Journal 4, pp 1 –13 (2003)More Less
There is sufficient evidence to support the advice that HIV+ patients should be encouraged to undertake regular exercise. They will experience a training effect dependent on the normal parameters of frequency, intensity, duration, and mode of exercise. The disease does place potential limitations to exercise, as the HI virus directly affects pulmonary, cardiac, skeletal muscle and endocrine function. The effects of these changes may be exacerbated by secondary infection and other pathological changes may be induced by treatment. The advent of highly active antiretroviral therapy has brought with it a range of metabolic changes that may also influence exercise participation. The limitations to exercise imposed by HIV infection and its treatment are reviewed.
Tropical infections in athletes : malaria, schistosomiasis and African tick bite fever : review articleAuthor Austin K. JeansSource: International SportMed Journal 4, pp 1 –12 (2003)More Less
Objective : This article reviews three common tropical infections, namely malaria, schistosomiasis and African tick bite fever, in order to highlight the risks posed to athletes travelling to endemic areas in Africa and provide physicians with an update on these diseases.
Data sources : A review of journal articles and abstracts, bulletins and publications by the World Health Organisation (WHO), the Centers for Disease Control (CDC), the Canadian Communicable Disease report, and the South African Department of Health, which were written between 1983-2003, was conducted. Clinical and biological data was reviewed in the Oxford Textbook of Medicine and Essential Malariology.
Study section and data extraction : 46 journal articles/abstracts and public health bulletins were reviewed, selected on their relevant contribution to data on clinical case reports, epidemiology, clinical disease features, diagnostic tests, preventive strategies and management protocols.
Data synthesis : This review found published case reports of and statistical data on malaria in travellers to tropical Africa, the biggest risk being that of P. falciparum infection. Similarly, there are published case reports of schistosomiasis and African tick bite fever in athletes and other groups travelling to endemic areas of Africa. From a review of recent journal publications, public health bulletins and relevant texts an updated presentation of the epidemiology and clinical features for each tropical infection and guidelines on management, prevention and prophylaxis is produced.
Conclusions : Malaria, Schistosomiasis and African tick bite fever are common tropical infections that pose a potential risk to athletes travelling, training or competing in tropical endemic areas of Africa. Practical guidelines for prevention / prophylaxis play a significant role in reducing the risks of infection for each of these tropical diseases. Physicians need to consider malaria especially P. falciparum, and African tick bite fever in febrile patients returning from Africa. Athletes who have contact with fresh water in endemic areas of Africa should be examined and tested for schistosomiasis.
Source: International SportMed Journal 4, pp 1 –12 (2003)More Less
Infections of the upper respiratory tract (URTI) are the most common type of infection throughout the population. Only a nuisance to the average citizen, they may disrupt training continuity and interfere with performance in athletes.
Objective : The aim of the present review was to summarise the present epidemiological knowledge on the incidence of URTI in athletes and its association with influencing co-factors such as training-load, sporting discipline, nutrition and life-style related variables.
Data Sources : MEDLINE was searched for pro- and retrospective studies investigating URTI and involving athletes, the literature compilations appended to the retrieved publications were then scanned for related and relevant articles.
Study Selection : 5 retrospective, 2 prospective and 3 randomised epidemiological studies involving athletes or having training and URTI as main issues were selected.
Data Extraction : From these investigations, the number of subjects investigated, the analysed variables and the main outcomes were retained.
Data Synthesis and Conclusion : In the investigated studies, there is general consensus that strenuous acute or chronic exercise is associated with an increased incidence of URTI in athletes, whereas moderate exercise seems to be protective. Several other factors favouring the development of URTI have been identified. Lifestyle variables, such as high stress levels, sleep deprivation and dietary unawareness, are important co-factors in the immune response.Furthermore, several nutritional supplements such as vitamin C, zinc, or other immune stimulants have been identified to affect human immune competence. However, the clinical significance of these laboratory findings remains yet to be determined.
Author Brian B. AdamsSource: International SportMed Journal 4, pp 1 –8 (2003)More Less
Athletes commonly encounter skin problems as a result of their exercise endeavours. Many of these dermatoses are related to skin infections. Bacteria, viruses, fungi, atypical mycobacteria, and parasites may all hinder athletes' performances. Regular surveillance by athletes and coaches assists in promptly identifying these skin infections. Prompt therapy helps to thwart team epidemics. Prevention is paramount and includes both pharmacological and non-pharmacological methods. This review article reviews in detail the epidemiology of skin infections, the clinical presentation of skin infections, the management of skin infections, and the prevention of skin infections.
Source: International SportMed Journal 4, pp 1 –14 (2003)More Less
Objective : This review evaluates the impact of exercise-induced changes in local immunity and the role of monitoring salivary IgA to identify the risk of upper respiratory tract infections (URTI).
Data sources : Data was sourced from primary research published in referred journals between 1980 - March 2003. Unpublished data from our own research has been included where appropriate.
Study section : Only studies utilising salivary IgA (Sal-IgA) to monitor mucosal immune status and evaluate changes in Sal-IgA in response to exercise at various intensities, in individuals of differing ages and fitness levels, and following dietary interventions were included. The relationship between Sal-IgA and URTI was assessed.
Data synthesis : There is considerable analytical and biological variance in the measures of Sal-IgA. High intensity exercise-induced Sal-IgA suppression may persist for several hours or days. Repeated, high intensity exercise in some individuals can elicit long-term Sal-IgA suppression, which is reversible. Moderate exercise enhances local immunity, which is greater in aerobically fitter individuals. Lower levels of Sal-IgA are associated with an increased risk of URTI in elite endurance athletes of varying ages, sports and fitness. A role for monitoring Sal-IgA has only been demonstrated for the long-term prediction of URTI risk on an individual basis. Sal-IgA is only a marginal predictor of short-term risk due to a high degree of analytical and biological variability.
Conclusions : Moderate exercise has the potential to improve mucosal immunity, while repetitive intense exercise can be immunosuppressive. Monitoring of Sal-IgA can be useful in research and clinical settings, but requires consideration of the factors affecting mucosal immune status.
Source: International SportMed Journal 4, pp 1 –15 (2003)More Less
Objective : This study reviewed the current literature that relates diet to immune function in athletes.
Data sources : Research from the authors' laboratory was combined with literature on diet and immune function in athletes using MEDLINE and library searches.
Study section : Athletes are exposed to multiple stresses (including physiological, psychological, environmental), which, together, may suppress the immune system. Dietary intake of carbohydrate (CHO), fat and protein are needed to meet the demands of exercise and to supply elements of the immune and antioxidant systems. Over-exercise or under-nutrition may negatively affect the defence systems.
Data extraction : Many athletes eat fewer calories than they expend, avoid fats and red meat, and thus may not have sufficient stores of intramuscular fat and micronutrients to support the immune system.
Data synthesis : Exercise stress leads to an increase in stress hormones and immunity, including : sympathetic nerve activity (SNA), catecholamine levels, cortisol, neutrophilia, lymphopenia, oxidative bursts, natural killer (NK) cell activity, lymphocyte proliferation, increased pro- and decreased anti-inflammatory cytokines. These responses are blunted by exercise training and exacerbated by overtraining or under-nutrition. It is clear that diets too low in total calories, or of insufficient calories from CHO, fats or proteins lead to greater immune and oxidative stress. Deficits in macro- and micronutrients can be made up by supplements; however, the evidence is not convincing that supplementing athletes on a balanced diet is beneficial.
Conclusions : Athletes should eat a diet where total caloric, CHO and fat calories are balanced against expenditure during training and performance to optimise performance, immune function and antioxidative defence.
An alternate approach to assessing immune function related to upper respiratory tract infection (URTI) : review articleAuthor Lucille Lakier SmithSource: International SportMed Journal 4, pp 1 –9 (2003)More Less
An increased incidence of upper respiratory tract infection (URTI) has been associated with acute, prolonged bouts of strenuous of exercise, as well as with strenuous training and overtraining syndrome. It has been assumed that the increased incidence of infection is associated with high volume/intensity training, resulting in immunosuppression. Although many aspects of immune function have been monitored, no cohesive pattern concerning alterations in immune function has emerged. The purpose of the present paper is to propose that the recent understanding of the dichotomy of T-helper (Thp) precursor lymphocytes into Th1- and Th2-effector lymphocytes may be applied to this field of research to provide a comprehensive explanation of alterations that may occur in response to strenuous exercise and the increased incidence of URTI. The dichotomy of Th-lymphocytes into Th1- or Th2- lymphocytes is dependent on the prevailing cytokine pattern. Interleukin (IL)-6 and IL-4 drives Tp-lymphocytes to a Th2/humoral response (HI), while IL-12 and interferon (IFN)γ drives Tp-lymphocytes to a Th1/cell mediated (CMI) response. The up-regulation of Th2/HI results in suppression of Th1/CMI, which would place the athlete at risk for URTI. Information gleaned from several exercise studies is suggestive of a post-exercise Th 2-lymphocyte response, with elevated levels of IL-6, IL-10 and IL-4, and an absence of type 1 cytokines (IL-12 and IFNγ ). The scenario of increased HI and suppressed CMI would provide an explanation for increased incidence of URTI after strenuous exercise. Recommendations are made to examine this postulate.