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The effects of an ultra-endurance event on heart rate variability and cognitive performance during induced stress in Ironman triathletesJoubert, Ilse January 2009 (has links)
Includes abstract. / Includes bibliographical references (leaves 55-79). / The effects of long-term participation in ultra-endurance exercise on the cardiovascular system have recently been the subject of much interest. It is well known that HRV, a marker of autonomic activity, is enhanced with long-term aerobic exercise training. However, after acute exercise, HRV is reduced, but recovers over time depending on the intensity of the prior bout of exercise. A limitation of previous research is that exercise bouts of only up to 120 minutes have been studied. A modified Stroop Task is a laboratory stressor to assess executive cognitive function by means of reaction time and accuracy. The resting HRV is directly related to these prefrontal neural functions, but the effect of an altered HRV on cognitive function has never been investigated. We determined the effects of an ultra duration (10 – 15 hours) exercise event on parameters of HRV and cognitive function during a Modified Stroop Task, 60 – 200 minutes after the 2007 South African Ironman Triathlon event (3,6km swim; 180 Km cycle; 42,2 Km run). 1 Female and 13 male competing triathletes (IRON; ages 33.7±7.9) and 7 control subjects (CON; 2 female and 5 males aged 42 ±4.5) completed a Modified Stroop Task before and after the event. The individual HRV parameters, heart rate (HR), respiratory frequency (RF), reaction time (RT) and % of mistakes made were recorded via the Biopac MP150WSW System (Goletta, California, USA). Data was transformed by auto regressive analyses (Biomedical signal analysis group, University of Kuopio, Finland) into LF (0.04 - 0.15 Hz) and HF (0.15 - 0.5 Hz) components. Additional calculations included %LF and %HF as well as the central or peak frequencies in both the LF and HF bands.
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The effect of musculoskeletal injury on endogenous nandrolone metabolismKohler, R M N January 2003 (has links)
Bibliography: leaves 55-66.
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Achilles tendon ultrasound findings in triathletes before and after the ironman triathlonSchwabe, Karen January 2006 (has links)
Includes bibliographical references (leaves 105-115). / The aim of this prospective cohort study therefoew was to assess the morphological and blood flow changes in the Achille tendons of triathletes competing in the 2006 South African Ironman Triathlon. / abstract
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Risk factors associated with a past history of Exercise Associated Muscle Cramps (EAMC) in Ironman triathletes : a case control studyShang, Gavin Sam January 2008 (has links)
Includes bibliographical references (p. 70-73). / The main aims of this dissertation are 1) to review the existing medical literature on the possible intrinsic and extrinsic risk factors for EAMC, and 2) to investigate risk factors that are associated with a self reported past history of EAMC in Ironman triathletes. The focus of this research is to increase the understanding of possible causes of EAMC, so that prevention and treatment strategies can be optimized.
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A comparison of two treatment protocols in the management of exercise-associated postural hypotension (EAPH) : a randomised clinical trialAnley, Cameron January 2007 (has links)
Includes bibliographical references (p. 79-83). / The aim of this study was to compare which of the two commonly used treatment protocols for Exercise Associated Postural Hypotension (EAPH) (Trendelenburg with oral fluids ad libitum or intravenous fluids) result in quicker recovery and earlier discharge from the medical facility.
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The association of the AVPR2 gene with serum sodium and water imbalances during an Ironman TriathlonAh Kun, Maresa January 2007 (has links)
Includes bibliographical references (p. 120-138). / It is well documented that participation in ultra-endurance events such as the Ironman Triathlon, can be associated with the development of post-race water and sodium imbalances in athletes. Variants within genes that encode for proteins that regulate thirst have been shown to be associated with weight changes during participation in an Ironman Triathlon. Recent evidence of mutations within the arginine vasopressin 2 receptor (AVPR2) gene, which encodes a constitutively active receptor in the collecting tubules of the kidney, resulted in increased water reabsorption and hyponatraemia in two unrelated male infants. This suggests that serum imbalances and hydration status in individuals participating in an endurance event may also be, in part, controlled by variants withink the AVPR2 gene. The aim of this study was to investigate whether polymorphisms within the AVPR2 gene are associated with exercise-associated serum sodium and/or water imbalances in triathletes who particpated in the 2006 South African Ironman Triathlon.
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The end of season electroencephalographic and neuropsychological status of a team of secondary school rugby players : a comparison between very mild traumatic brain injury and a sedentary control groupDijkstra, Hendrick Paulus January 2004 (has links)
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.
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Respiratory health of the endurance athlete : prevalence of respiratory related conditions/illnesses in endurance athletesCloete, Carolette January 2011 (has links)
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.
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The relationship between training/match load and injuries in academy players during a provincial under 19 rugby union seasonVan Wyk, Johan January 2015 (has links)
Includes bibliographical references / Background: The influence of professionalism has filtered down to junior levels in rugby union. The increased demands on junior professional rugby players has an impact on their fitness characteristics, training load, match load and injury profiles. Although many studies have been conducted on senior rugby union players, not much is known about junior players as they make the transition into the senior ranks. The aim of this study was to describe the training/match load during the pre-season and competitive in-season in a squad of under 19 academy rugby players and then to relate this to the injuries (contact and non-contact) sustained during the different phases of the season. A secondary aim was to measure the physical ability of the players through the season. Methods: Injury and training data from players in the Western Province under 19 Currie Cup squad (n=34) were recorded on a daily basis throughout the rugby season (42 weeks). The training load was represented by the time (minutes) spend in each activity associated with training, conditioning and match play. The players also underwent measurements of body mass, stature, body fat percentage, upper body muscular endurance (pull ups), and muscular strength (1RM bench press), sprint times (10m and 40m) and anaerobic capacity (5 meter shuttle run). All tests were conducted in January and June, which coincided with the beginning of pre-season and the beginning of the competition phase respectively. Results: Over the season 71 injuries were recorded, comprising 17 pre-season injuries, 18 pre-competition injuries and 36 competition phase injuries. There was no difference between the occurrence of contact and non-contact injuries during the different phases of the season. Although there was no significant difference between the injury rates during the different phases of the season, there was a significant difference between the injury rates in training (4.4/1000 player hours) and matches (74.1/1000 player hours). The most common body parts injured were thighs, hip/groin, ankles and shoulders, with injuries to the hand/finger and knee being the most severe. Muscles and ligaments were the structures that got injured the most. The average duration of days to return-to-play after an injury was 17 days. There were significant changes in the physical characteristics of the players in the six months between the test batteries. In addition to getting taller, players generally improved their fitness characteristics with significant improvements occurring in the bench press (8%), pull ups (113%), vertical jump (13%) and the 5 meter shuttle run (6%). Conclusion: The training load of the junior professional rugby players is similar to the load of senior professional rugby players. This represents a sudden increase compared to the previous year when the players were at school. A long-term research project with a database of rugby schools will assist in bridging the gap between the demands of junior rugby and junior professional rugby. Players joining a professional academy system after school need physical, emotional and tactical fast tracking as they are competing in a highly competitive environment for senior professional contracts. This accounts for the relatively high rate of injury throughout the season. Players need to be carefully monitored and managed during the season to detect symptoms reflecting poor adaptation to the training load.
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Recruiting in College Sports: Effects of Recruiter Characteristics on Recruiting Effectiveness in Division I Women's SoccerUnknown Date (has links)
A multitude of studies have examined key factors influencing college or university selection by student-athletes. Much less attention, however, has been given to the roles of athletic recruiters and how their qualities and characteristics impact recruiting outcomes. Therefore, the purpose of this investigation was to examine the impact of recruiter (head coach) characteristics on recruiting effectiveness (total quality of recruits signed) in the context of NCAA Division I women's soccer. Recruiter characteristics included in this study were political skill, the Big Five personality dimensions (i.e., extraversion, agreeableness, conscientiousness, neuroticism, openness), behavioral integrity, and two performance reputation characteristics (i.e., head coach career record and final team NCAA rank). Over 130 (N = 131) head women's soccer coaches participated in this study. The direct effect of these nine predictor variables on the outcome of total quality of recruits signed (recruiting effectiveness) was assessed using multiple regression analysis. It was determined from the results that six of the nine recruiter characteristics (i.e., political skill, agreeableness, neuroticism, behavioral integrity, career record, and NCAA rank) had a significant impact on recruiting effectiveness. / A Dissertation submitted to the Department of Sport Management in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2011. / August 2, 2011. / Personality, Political skill, Recruiter characteristics, Recruiting, Reputation, Women's soccer / Includes bibliographical references. / Michael Mondello, Professor Directing Dissertation; Gerald R. Ferris, University Representative; Yu Kyoum Kim, Committee Member; Pamela L. Perrewé, Committee Member.
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