Includes bibliographical references (leaves 70-78). / Although the incidence and consequences of mild traumatic brain injury (MTBI) in secondary school rugby has been well documented, little is known about the incidence and consequences of repetitive sub concussive injuries - the so called very mild traumatic brain injuries (vMTBI). The aim of this study was to compare the end of season neuropsychological and electroencephalographic (EEG) status as well as the academic performance of players in a secondary school rugby team who, during the course of the season sustained only repetitive vMTBI to those players who sustained MTBI and a sedentary control group.

Includes bibliographical references (pages 97-102). / Background: Endurance athletes, in particular triathletes and ultra-distance runners, undergo high volumes of intense training in preparation for events. There is recent epidemiological evidence that the respiratory tract is the most common system affected by illness in athletes during tournaments. Respiratory tract symptoms have also been shown to affect endurance athletes particularly in the post- event period. However, the prevalence of respiratory related illnesses including respiratory tract symptoms, asthma, and allergies in the pre-race period has not been well studied in endurance athletes. Objective: The main aims of this dissertation were 1) to review the existing literature focussing on the epidemiology, pathogenesis, possible aetiology and management of respiratory tract symptoms, asthma and allergies in athletes, and 2) to conduct an investigation to determine the pre-event period prevalence (6 weeks and 1 week before an event) and nature of respiratory tract symptoms, asthma and allergies in Ironman triathletes and ultra-distance runners. Methods: In the first part of the dissertation, a review of the literature pertaining to respiratory tract symptoms and illness was undertaken. In the second part of the dissertation, a cross-sectional descriptive study was undertaken in 441 triathletes entering the 2006 and 2007 Ironman Triathlon, and 152 ultra- distance runners in the 2009 Two Oceans Ultra-marathon. In the 1 to 3 days before the race (registration period), participants were requested to complete a validated pre-event medical questionnaire containing sections on demographics, training and previous competition, common medical conditions and detailed sections on respiratory symptoms in the 6 weeks and 1 week period before the race, as well as asthma and allergies experienced. Respiratory symptoms were divided into upper respiratory tract symptoms (URTS), lower respiratory tract symptoms (LRTS) and systemic symptoms (SS). All data obtained regarding these respiratory related illnesses were compared between the triathlete group and the ultra- distance runners. Results: The main findings in the experimental section of the dissertation were that 1) triathletes trained significantly more hours in the 6 weeks and 1 week before an event than ultra-distance runners, 2) the period prevalence (6 weeks before the race) of respiratory tract symptoms was 50% of triathletes and 35% of ultra-distance runners, 3) upper respiratory tract symptoms and particularly nasal symptoms (nasal congestion and rhinorrhoea) were significantly more common in triathletes (21 to 27%) in comparison with ultra-distance runners (12 to 17%), 4) systemic symptoms (especially pyrexia) were significantly more common in ultra-distance runners in the 1 week before an event (9.2 vs. 2.4%), 5) the point prevalence of self-reported asthma was low in both study groups (ultra-distance runners 3.4% and triathletes 8.3%) although symptoms of dry cough, wheezing, shortness of breath and "tight" chest were reported by 25 to 80% of athletes in both study populations, 6) in most cases the diagnosis of asthma was made by means of history taking and a physical examination by a physician, 7) majority of triathletes used beta 2-agonists only as the treatment of choice for asthma symptoms, while ultra-distance runners used combinations of corticosteroids and beta 2-agonist inhalers as first line treatment, 8) allergies were reported by 34% of triathletes and 22.3% of ultra-distance runners, 9) most allergic symptoms in both study groups were confined to the upper respiratory tract with hay fever ranging from 77 to 83% and sinusitis 55 to 64.2%, and 10) the most common medication used for allergies by triathletes and ultra- distance runners, were anti-histamine tablets. Conclusion: There is a high period prevalence of respiratory symptoms in triathletes and ultra-distance runners in the 6 weeks before an endurance event. Triathletes had a significantly higher prevalence of upper respiratory tract symptoms (especially nasal symptoms) in comparison to ultra-distance runners, which might be related to allergies and a higher training volume. There also appears to be a lack in proper diagnostic evaluation of asthma in these endurance athletes with suboptimal and improper treatment of asthma and allergies. Approximately 10% of ultra-distance runners had systemic symptoms in the week before the event, indicating a lack of athlete education on possible risks of exercising with a systemic illness.

The medical profession has increased its acceptance of the benefits of exercise training for patients with uncomplicated coronary artery disease. Access to more modem technology and better management of this condition has led to an increase in the number of patients surviving acute coronary episodes . Some of these patients may have developed chronic asymptomatic left ventricular dysfunction and/or residual myocardial ischaemia, and could become potential candidates for cardiac rehabilitation if exercise training could induce physiological benefits without further deteriorating their condition. Over the last 10 years, several patients at moderate to high risk of future cardiovascular events because of the presence of left ventricular dysfunction and/or myocardial ischaemia have been accepted for cardiac rehabilitation at the Johannesburg Cardiac Rehabilitation Center. The purpose of the study was to evaluate the effects of exercise training on left ventricular function and exercise capacity in patients with coronary artery disease and varying degrees of left ventricular dysfunction and/or myocardial ischaemia attending the Johannesburg Cardiac Rehabilitation Center.

Includes bibliographical references (leaves 69-77). / Triathletes, in particular Ironman triathletes, undergo intense training and compete in a very physically demanding race. Medical conditions in the pre-race period in these triathletes have not been well documented, but there is evidence form other endurance sports that symptoms of respiratory tract infection are particularly common. However, the prevalence, causes and consequences of these symptoms have not been studied in Ironman triathletes. The aims of this study were: 1) to determine the incidence of respiratory tract symptoms (RTS) in triathletes preparing for an Ironman Triathlon, 2) to establish the factors associated with the development of these RTS, and 3) to determine the effects of the RTS on pre-race training and race performance. Methods: In this cross-sectional descriptive study, 304 triathletes entering the 2006 Ironman triathlon in South Africa were recruited as subjects. All the subjects completed a validated questionnaire in the 1-3 days before the race (during registration). The questionnaire contained sections on demographics, training and previous competitions, common general medical conditions that they may have experienced, and a detailed section pertaining to RTS and allergies, including use of medication. Data on race performance was collected after completion of the race. Subjects were divided into the following groups, based on their self-reported history of RTS in the 6 weeks period prior to the race: no RTS, all RTS, only upper respiratory tract symptoms (URTS), lower respiratory tract and/or systemic symptoms (LRT +SS).

The purpose of this thesis is to establish if there is any evidence to support the hypothesis that altered ventricular loading conditions after the cessation of exercise may cause "cardiac fatigue". The studies that have shown post-exercise "cardiac fatigue" have not controlled for either preload or afterload or both, before and after exercise. These studies may rather have identified the effects of alterations in peripheral vascular function on left ventricular function after prolonged exercise. The research study in this thesis is to evaluate if the loading conditions of the heart affect the echocardiographic measurements after exercise that may be misinterpreted as "cardiac fatigue". Echocardiography as a tool of cardiac evaluation cannot be done during exercise because of the technical difficulty of doing a cardiac ultrasound on a human being in motion. The studies that have investigated post exercise "cardiac fatigue" have therefore measured cardiac function after exercise and retrospectively assumed that the cardiac dysfunction was present during exercise since the cardiac demands are at their peak during exercise. However, the post exercise period may be associated with altered loading conditions that may cause changes in the echocardiographic measurements that are similar to cardiac abnormalities.

Includes bibliographical references (leaves 87-103). / Ultra-endurance events, in particular Ironman Triathlons, are physically very demanding for the competitors. There is a large body of evidence showing the Upper Respitory Tract Symptoms (URTS) are very common in athletes in the 2-week period after such an event. However, there is no definitive explanation as t the exact cause of mechanism for the development of post-race URTS. The aims of this study were: (1) to determine the incidence of post-race URTS in triathletes competing in an Ironman Triathlon; (2) to identify clinical and immunological factors that are associated with the development of post-race URTS in these triathletes. In this prospective cohort study, 99 triathletes entering the 2006 South African Ironman Triathlon were recruited as subjects. All the subjects completed a validated questionnaire in the one to three days before the race (during registration). The questionnaire contrained sections on demographics, training history and previous performances, common general medical conditions that they may have experienced, and a detailed section pertaining to respiratory tracgt symptoms (RTS) and allergies. At registration, each subject had a blood sample taken for analysis of cytokines representing mainly a TH1 response (IL-2, and IL-12) (cell mediated immunity) and a TH2 response (IL-4, IL-6, IL-10) (humoral immunity), as well as a saliva sample (for salivary α-amylase, cortisol and IgA concentrations). Collection of blood and saliva samples was repeated immediately post-race. Data regarding race performance was collected within one week after completion of the race.

Several epidemiological reports suggest that athletes engaging in marathon-type running events are at increased risk of symptoms of upper respiratory tract infections (URTI). A possible explanation for this increased susceptibility is that during prolonged, strenuous exercise, production of immunosuppressive oxygen free radicals is increased. The purpose of this study therefore was to examine the effect of anti-oxidant vitamin supplementation on the incidence and severity of post-race symptoms of URTI's among athletes competing in a 90-kilometer ultramarathon footrace. A double blind, randomised, placebo controlled study design was employed. Eighty-five subjects were divided into three experimental and three control groups. Each athlete selected a non-running partner with whom they were paired. This non-running control was of a similar age and was a member of the same household or otherwise closely associated with the runner. The experimental and control groups were divided into those ingesting 250 mg/day of ascorbic acid (n = 13 runners, 11 non-running controls), or 4.5 mg/day of beta-carotene (n = 12 runners, 11 non-running controls) or placebo (n = 19 runners and 19 nonrunning controls). All groups commenced supplementation six weeks before the ultramarathon and continued for two weeks after the race. The runners and non-running controls experienced the same incidence of symptoms of upper respiratory tract infections during the study period (50% and 53% respectively) but significantly more runners than non-running controls experienced severe symptoms of upper respiratory tract infections of infective origin (45% and 18% respectively, p < 0.01). Of the runners, 30. 8% on supplemental ascorbic acid, 41. 7% on beta-carotene and 68% on placebo developed symptoms of URTI's. The comparative figures for non-running controls were 45.5%, 45.5% and 63% respectively. All of the non-running controls (100%) and 80% of the athletes who developed severe symptoms of URTIs were on placebo medication. Al though post-race symptoms of URTI 's are common in distance runners, prolonged, strenuous exercise itself is only one of a number of risk factors for symptoms of URTI. However, ingestion of supplemental anti-oxidant in the form of ascorbic acid or beta-carotene for an eight-week period before and after an endurance running event significantly decreases the severity of athletes' symptoms of upper respiratory tract infections.

Very little data exists on swimmers in South Africa. A series of three studies were undertaken to assess the medical status of young swimmers in the Western Cape, their training habits and how these related to performers. The aim of the first study was to determine the training habits of young competitive swimmers, whether there were gender differences in training, and whether the training habis changed over a three-year period (1995-1998). The second study assessed the prevalence of existing medical conditions in young competitive swimmers and whether there were gender differences amongst the swimmers for the various medical conditions. In the third study, mood changes in young competitive swimmers were monitored over a swimming season to determine whether a relationship exists between mood states and swimming performance.

Background: The association of psychological factors with athletic performance and proneness to injury and illness has been widely recognised as an integral part of athletic preparation, treatment and rehabilitation. The exact nature of this association is still not clear, but it can be hypothesised that better mental health leads to better performance, less injuries and illness and more rapid recovery. Psychological distress is a strong predictor of injury, illness and poor performance, but inherent personality traits have failed to show a constant association with these parameters. Advances in validated psychometric instruments of personality and resilience show promise in their application to further the understanding of the psyche in athletes. Objective: The aim of this study was to evaluate the predictive value of personality traits (novelty seeking, harm avoidance and reward dependence), resilience and general psychological distress in terms of injury, illness and performance in a group of triathletes competing in the 2007 lronman Triathlon. Methods: For this descriptive cross-sectional study, 166 entrants in the 2007 lronman Triathlon were recruited. Each subject completed a detailed, previously validated set of questionnaires during registration prior to the event. Contained in the questionnaire were sections on general demographic information, detailed previous and current medical conditions and injuries, and psychometric instruments (TPQ - a measure of personality, CD-RISC - a measure of resilience, K10). After the event, the official overall finishing times, as well as the split times for the swimming, cycling and running legs, were obtained from the race organisers. Results: Higher NS and RD scores were predictors for faster predicted performance times and higher psychological distress scores was a predictor for slower actual times (r=0.160, P=0.053) and particularly predicted slower cycling times (r=0.026, P=0.002). Higher K10 scores significantly predicted the presence of flu-like symptoms (P=0.019) and higher HA scores significantly predicted nervous system symptoms during exercise (P=0.035). Higher RD scores predicted the absence of nervous system symptoms (P=0.075). Higher K10 scores (P=0.093) and HA scores (P=0.070) were associated with medication use prior to and during the event. Higher resilience scores predicted the occurrence of exercise associated collapse (P=0.081) and absence of EAMC (P=0.075). Higher HA scores predicted GIT symptoms during exercise (P=0.091 ). Higher reward dependence predicted the presence of tendon / ligament injuries (P=0.039) and genital injuries were associated with lower resilience (P=0.098) and higher HA scores (P=0.065). Conclusion: Generally, the results showed only a few consistent findings in terms of identifying predictors, although interesting correlations and trends were observed. Studies on different athletic populations and on a larger scale are needed. Physicians should be aware of the cardinal importance of mental well-being, as this is as vital in the preventative and curative management of the injured, ill or poor performing athlete as optimal physical conditioning.

Osteoarthritis (OA) is the most common degenerative joint disease. The impact loading on the articular cartilage of the large weight bearing joints (hip, knee, and ankle joints) during distance running might be a potential precipitating factor in OA. The aim of this case-control study was to investigate the relationship between total accumulated running volume and OA in the weightbearing joints. In this study, OA was defined as pain and/or stiffness and/or swelling in the weight-bearing and non-weight-bearing joints (wrists and fingers). The subjects for this study were selected from previous and current runners of the Two Oceans Ultra-marathon (56 km) in Cape Town (South Africa). The database (1356) consisted of all the runners who participated in this race between 1970 and 1983. From this data-base a random group of male runners (n =128) were divided into six 10-year age groups of runners (18 and 79 years). There was a random sample of 25 runners in five of these groups and three in the 70-79 year age group. Runners were age matched with a random sample of past pupils (n=204) of a school who were in their final year between 1923 and 1994. This was the control group. A questionnaire to diagnose OA was designed and validated with a sensitivity of 92% and a specificity of 71 %. The questionnaire was posted to the runners and controls. Incentive prizes were offered to improve the response rate, which was 59%. Completed information was obtained from 76 ultra-distance marathon runners (response rate 59%) and 114 controls (response rate 56%). In the control group there was a group who participated in running. This group was combined with the runners who were then divided into three groups according to their total running volume which was calculated by the following formula; years involved in running x months/year running x 4 x hours/week running. The subjects were thus divided into four groups: 1) controls (non-runners) (n=60), 2) low volume runners (n=43), 3) medium volume runners (n=43), and 4) high volume runners (n=44). Of these, 22 low volume runners, 7 medium runners, and 7 high volume runners stopped running. The prevalence (%) of OA in all groups was compared. The mean age of the control group was significantly higher than the three running groups. The mean height and weight of the medium volume group was significantly higher than the other groups. There was no significant difference in the BMI in each group. The frequency of professional and retired people was significantly higher in the control and each running group. A significantly greater percentage of controls had a history of admission to hospital. There were more controls on long-term medication, compared to runners. A significant number of injuries to the weight-bearing joints (specifically the knee joint) occurred in all groups, due to other sports (p =0.007). There were no significant differences in symptoms suggestive of OA in all groups when not adjusting for age and previous injuries. However, when assessing the odds ratio to determine the risk for OA in the weight-bearing joints, adjusting for age and previous injuries, the low volume group had the highest risk to develop OA (O.R. = 3.2, 95% C.I. = 1.0-10.3); the medium group had the second highest risk (O.R. = 1.7, 95% C.I. = 0.6- 4.8) and the high-volume group (O.R. = 1.1, 95% C.I. = 0.4-3.1) and control groups (O.R. = 1.0) had equally the lowest risk to develop OA. This study confirmed that distance running is unlikely to be a predisposing factor in the development of OA in the weight-bearing joints, even at high running volumes commonly seen in ultra-distance running.