Human Movement and Biokinetic Sports Science
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- ItemSelected genes polymorphism related to biomarkers and physical characteristics in young African cricket rugby soccer netball players and Bulgarian athletes(University of Zululand, 2019) Mugandani, Sam ChenjeraiSelected genes polymorphism related to biomarkers and physical characteristics in young African cricket rugby soccer netball players and Bulgarian athletes
- ItemVisio-spatial intelligence (vsi) between premier league, first division rugby players and non-athletes in the development of a sportspecific visio-spatial intelligence test battery(University of Zululand, 2020) Millard, LourensCompetitive rugby is a popular sport in South Africa, that not only serves as a major commercial platform viewed by millions of spectators weekly, but also hosts a large number of players that participate in the sport. Athletes in any sport can spend hours training in order to improve their strength, speed and the endurance of their muscles. However, if their visual processing capabilities are inadequate, their physical training may not be optimised and thus their performance will suffer. Despite this, sport vision has only received attention in relation to research in recent years. The reliance and importance of the visual system necessitates the need to determine the factors that affect an athlete’s ability to obtain and respond to appropriate visual stimuli. To date, research has focused on individual factors that affect vision and visiospatial intelligence (VSI). However, a combination of factors could warrant a more holistic approach. This study summarised and compiled an overview of the factors affecting vision and VSI in athletes, covering those factors previously connected with sport, as well as those hitherto not yet associated with athletic activities, but that could also play a part in sporting performance. In this study, fourteen factors affecting vision and VSI in athletes were identified, and this compilation provides a starting point for further study. This study reveals that many factors can affect vision and VSI, and could add significantly to the processes relating to visual testing of athletes and assessments of their decision-making skills. This study further indicates that while current research still tends to focus on single factors affecting vision and VSI, a large number of these factors have been identified and empirically researched. This offers new opportunities for researchers to investigate the effects of a combination of factors, and for coaches to explore further possibilities for competitive advantage. Research suggests that athletes have enhanced visio-spatial expertise in comparison to non-athletes. However, conflicting research suggests that this is not always the case as non-athletes possess similar visio-spatial expertise in certain visual skills. In this regard, the present study has compared the visual expertise of first-division rugby players to non-athletes. Participants underwent an optometric assessment after which the following six VSI components were measured, namely; accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, visual memory and hand-eye coordination using the following tests: hart near far rock, saccadic eye movement, evasion, accumulator, flash memory and ball wall toss tests. Results indicated that first-division rugby players performed significantly (p ≤ 0.05) better in five of the six tests, with the exception of visual memory (p = 0.893). While this study substantiates the notion that athletes, in this case first-division rugby players, perform significantly better in most VSI components, this is not the case for all aspects of vision. Further, this study attempted to discern whether Premier League rugby players have superior VSI in comparison to non-athletes when comparing six visual skills namely; accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, visual memory and hand-eye coordination. As with first-division rugby players, a statistically significant (p ≤ 0.05) difference existed between Premier League rugby players and non-athletes for five out of the six tests. Conversely, no real evidence is shown that visual memory differs between Premier League rugby players and non- athletes (p = 0.599). While novices in sport possesses similar visual skills to that of experts playing at a higher level, there may be major differences in performance in these VSI skills. In addition, expert athletes may only demonstrate superiority in specific vision skills and not all aspects of vision. Thus, the present study compared the performance of Premier League rugby players (n = 40) and first-division rugby players (n = 40) on six specific components of vision, namely; accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, visual memory, and hand-eye coordination. Premier League rugby players performed significantly (p ≤ 0.05) better than the first-division rugby players in five of the six tests, but were found to be similar in visual memory performance (p = 0.810). The findings of the present study indicate that first-division and Premier League rugby players have superior VSI when compared to non-athletes. What is particularly noteworthy is that non-athletes are not worse than either first-division or Premier League rugby players with regards to visual memory. Further, while this study substantiates the proposal that expert athletes, and specifically rugby players, have superior visual expertise to novice athletes, it also found that this is not the case with all vision skills. Again, no difference was found in visual memory between novice (first-division) and expert (Premier League) rugby players. These findings suggest that sport-specific vision testing batteries may be required to distinguish high performers from low performers in the same vein as physical tests are utilised in the selection and recruitment of athletes. In this regard, the present study proposes a rugby-specific test battery in an attempt to distinguish high VSI performers from low VSI performers.
- ItemComparison of anaerobic and aerobic fatigue on visual skills(University of Zululand, 2021) Shaw, Brandon StuwartExercise-induced fatigue is a common concern among individuals performing physical activities either for training and/or athletic performance. An enormous amount of research has been conducted on exercise-induced fatigue and its effect on physiological and physical functions. However, it is only supposed that maximal and supra-maximal exercise efforts may be responsible for decreases in sports vision performance and that physical conditioning may increase an athlete’s ability to delay mental fatigue and thus deterioration in sports vision performance. However, previous research has demonstrated that anaerobic alactacid and anaerobic lactacid exercise improves components of sports vision (i.e. peripheral threshold detection and coincidence-anticipation) and may result in instantaneous improvements in sports vision performance. Thus, the primary aim of the study was to investigate the effects of short- and prolonged-duration maximal exercise effects on visual performance. The secondary aim was to examine and compare whether short- and long-duration maximal exercise most affects visual performance. Sixty untrained males were assigned to a control group (n = 30) or treatment group (TG) (n = 30) and underwent a sport vision test battery consisting of quantitative testing for accommodation facility, saccadic eye movements, speed of recognition, hand-eye coordination, peripheral awareness, and visual memory. One week later, the TG participants returned to complete a short supramaximal effort cycle ergometer test (SCT) immediately followed by the sports vision test battery. One week thereafter, TG participants returned a second time and completed a prolonged incremental maximal treadmill test (PTT) immediately followed by the sports vision test battery. In the SCT, significant (p ≤ 0.05) changes were found for five of the six sports vision performance measures (p = 0.000), except visual memory (p = 0.242). In turn, following the PTT, significant changes were found for all sports vision performance measures (p = 0.000 for all measures). Results further indicate that only accommodation facility (p = 0.005) and saccadic eye movement (p = 0.026) were statistically different between the SCT and PTT with these variables being significantly higher following the PTT. This study’s findings point to a beneficial immediate improvement in sports vision performance following short-supramaximal or prolonged-maximal exercise efforts, with the latter being found to be even more effective. Combining such exercise regimes as a functional warm-up may attenuate improvements in sports vision performance, especially in those sports requiring a great deal of visual processing and performance.
- ItemEffects of dehydration, hyperthermia, cognition aspects and fatigue balance on sport performance(University of Zululand, 2021) Dube, AdieleThis dissertation presents two studies. The first is a systematic review, aimed at investigating the effects of hypohydration and fluid balance on athlete’s cognitive function. PubMed, Sports Discuss, and Ebsco databases from 2005 to 2020 were searched for studies reporting on hypohydration, fluid balance, and heat on cognitive performance in sport. Search phrases included hydration, dehydration, fluid balance, mood, cognition, vigilance, decision-making, and brain. Participants in the studies received either fluid or none during exercise. Twenty-four trials (n=493 participants) from 24 articles met the inclusion criteria. Significant hypohydration, >2% body mass loss was reported consistently in 16 publications. Five articles reported that hypohydration was associated with heat stress and that limited fluid intake (3-5% body mass loss) impaired cognitive performance. Mood disturbance, fatigue, and ratings of perceived exertion constantly complemented hypohydration impairment on cognition. The second study examined the effects of exercise heat-stress, hyperthermia, dehydration, and fatigue on cognitive performances in semi-professional athletes. Eighteen healthy, active male athletes from individual and team sports who met the following criteria were chosen to participate in the study: age (25 ± 5) years, weight (69.3±6.6) kg; height (172.5±7.8) cm, BMI (23.2±0.9) kg/m² and body fat % (9.2±1.8). Participants completed a cognitive and mood test battery prior, immediately after, and post 120 minutes of treadmill exercise. A soccer-specific intermittent treadmill exercise protocol was completed in four experimental trials in temperate (normothermic) and hot (hyperthermic) conditions. Participants were hydrated and dehydrated in both conditions. Trial conditions were normothermic 16.4±0.02°C and 52±1% relative humidity, while hyperthermic 33.9±0.3°C and 61±1% relative humidity. Response times for the Stroop effect and Visual search tasks were quicker (584 to 690ms, p=0.001; 1978 to 2213 ms, p=0.003) in the heat. Cognitive tasks showed that reaction time, visual process, motor speed, and mood were similar in normothermic (p=0.001). ii Accuracy improved in hydrated hyperthermic by 1.2% (p=0.002) in Visual search. Total Mood Disturbance was significant in heat (p<0.001). Hydration status had no main effect in all cognition performance markers except for mood. Exercise-heat stress, hyperthermia, dehydration, and hypohydration impaired cognitive performance and mood at higher levels of 3-5% body mass loss. The response times and accuracy improved following the cognitive testing in semi-professional athletes exercising in relatively humid, hot conditions. Athletic and cognitive performances were relatively affected by hypohydration, which can indicate an athlete’s hydration status needs to be closely monitored during exercise. The findings of this study obtained from Eswatini individual and team sport athletes support that maintaining normal hydration has low physiological strain on athletic and cognitive performance
- ItemIdentification and modification of cardiometabolic disease risk factors in South African urban primary school children(University of Zululand, 2018) van Biljon, Anneke; Semple, S.J.; McKune, A.; Kolanisi, U.The initial asymptomatic process of atherosclerosis is known to develop in childhood and is associated with increases in cardiometabolic disease (CMD) risk factors. Low physical activity (PA) levels and sedentary lifestyles have been identified as contributory factors to CMD. In addition, PA levels are known to influence the function of the cardiac autonomic nervous system (ANS), and are a possible mechanism for explaining the association between insufficient PA, morbidity and mortality. Consequently, it has been proposed that sufficient PA may enhance cardiac ANS activity in children. However, there is still a lack of consensus on the exact dosage of exercise required for optimal ANS adaptation. This thesis aims to identify and modify the risk for CMD in urban primary school children. A cross-sectional study was performed to establish PA levels in South African primary school children. This was followed by a study that examined associations between individual CMD risk factors and altered ANS activity. The effect of two different exercise doses on CMD risk factors in overweight children was explored in a pilot study that lead to the quasi experimental study where the effectiveness of isocaloric exercise protocols on CMD risk factors and cardiac autonomic modulation in children were explored. Exercise interventions were set at either 65% to 70% of the maximum heart rate (MHR) in the moderate-intensity continuous training (MICT = 29) group or >80% MHR in the high-intensity interval training (HIIT = 29) group, or the interventions were combined in the alternate (ALT = 27) group. Heart rate variability (HRV) was used to measure cardiac ANS activity. Overall, we found significant discrepancies in PA levels among gender, age and ethnic groups, raising important questions about population group equality in terms of access to participate in PA. The second cross-sectional study established strong associations between individual CMD risk factors and cardiac ANS activity. Lastly, the pilot study showed different cardiometabolic effects induced by moderate-intensity and vigorous-intensity. While the quasi experimental study demonstrated that both the magnitude and components of CMD risk factors and ANS relate to exercise intensity. When the effects of these interventions were examined, enhanced vagal activity (RMSSD, pNN50, SD1) seemed to be achieved through high-intensity interval training (HIIT), when compared with moderate-intensity continuous training (MICT). In conclusion, this thesis provides evidence that HIIT induces more superior cardioprotective effects in children than does MICT. The favourable outcomes of HIIT may have important clinical implications in regards to reducing the risk of developing CMD; however, studies that implement longer terms are required to confirm the findings.