Thesis (M.A.(Biokinetics, Sport and Leisure Sciences))--University of Pretoria, 2004. / Summary in English and Afrikaans. Includes bibliographical references.

No description available.

The purpose of this study was to determine the effects of an aerobic training program on the aerobic fitness and blood lipid profiles of 24 premenarcheal (PREM) and 41 postmenarcheal (POSTM) volunteers. A second intent was to test for differences in the responsiveness of the two maturity groups to the program. Subjects in each maturity level were assigned to a control (C) or training (T) group. Training consisted of 30 min continous cycling at 75% max heart rate, three times per week for 12 weeks. All subjects were tested before the training, at week 6 and at the end of week 12. Anthropometric measurements, ventilatory threshold (VT), VO2 max and anaerobic capacity (AC), measured as total work performed during a 30 s Wingate test, were determined for all subjects at each test period. Serum total triglycerides (TG), total cholesterol (TC), low density (LDL-C), very low density (VLDL-C), and high density (HDL-C) lipoprotein cholesterols as well as subfractions HDL2 and HDL3 were measured pre and post training. Analysis of variance with repeated measures revealed that both PREM groups increased their VO2 max (p $<$.001), however the increase in PREM-T exceeded that of PREM-C (p $<$.01). A training effect for VO$\sb2$ max was also observed in the POSTM-T compared to POSTM-C subjects (p $<$.001) and this increase was similar to that of PREM-T. No changes in serum TG, TC, LDL, VLDL, or HDL were reported for any group. HDL2 values decreased in all groups (p $<$.001), with larger change occurring in the PREM subjects (p $<$.001). Although an increase in HDL3 was observed for all groups (p $<$.001), the increase in PREM was greater than in POSTM (p $<$.01). No training effect was found in either HDL subfraction. It was concluded that VO2 max was equally sensitive to the endurance training in both PREM and POSTM subjects. It was also suggested that, in young females, VT and AC may not be as responsive to endurance training as VO2 max. The lack of a training effect on the blood lipids and lipoproteins may be attributed to the normal concentrations in the subjects prior to the study. It is also possible that 12 weeks were insufficient to produce changes in the blood lipid profiles of the subjects. / Graduate

Background: The musculoskeletal demands placed on the lower limb musculature of fast bowlers over time have not received much attention. In particular, measures of muscle recruitment changes have, to the author’s knowledge, not been considered. Objective: The present study, therefore sought to establish any associations between an eight over, simulated fast bowling spell, and muscle activation patterns, power output, perceptual demands, and changes in performance. This will enable improvements in the development of training programmes. Methods: Players’ were required to attend two sessions in total. The purpose of the initial session was to collect specific demographic, anthropometric and physiological data and injury history information from each player. In addition, this first session allowed for habituation with the treadmill, the jump meter and all other equipment involved in experimentation. The second testing session involved electrode attachment sites being identified on player’s dominant leg. The areas were then shaved, wiped with an alcohol swab and left to dry, to ensure good connectivity. Pre- and post- measures of muscle activity and functional strength of the lower limbs were recorded in the Department of Human Kinetics and Ergonomics. The protocol took place at the Kingswood High Performance Centre, which is in close proximity to the initial testing site. The protocol involved players bowling eight overs (48 balls). During the protocol, accuracy, ball release speed and perceptual measures were recorded at the end of each over. After the protocol, players were driven back to the Human Kinetics and Ergonomics Department where post-testing measures were completed. The dependable variables of interest were muscle activation, functional strength of the lower limbs, ‘local’ ratings of perceived exertion (RPE), body discomfort, accuracy, and ball release speed. Results: For all muscles it was shown that, as the speed increased so did the muscle activity in players’ lower limbs. There were no significant changes in muscle activity preversus post-protocol. There was however, a general trend of decreasing muscle activity post protocol at higher testing speeds. There were significant (p<0.05) decreases in peak power following the simulated eight over bowling spell. ‘Local’ RPE displayed a significant (P<0.05) increase with each additional over and were observed to reach the ‘heavy’ category. The players’ highest discomfort area was in the lower back, with 13 players perceiving discomfort in this region following the eight over spell. The shoulder and chest were another two areas player’s indicated discomfort with eight players selecting the dominant shoulder. Seven players complained of the dominant side pectoral muscle, leading foot and dominant latissimus dorsi muscle being uncomfortable. Interestingly, the dominant pectoral showed the highest body discomfort ratings amongst players. There were no significant changes in accuracy between overs although there were large interindividual differences in accuracy points between players. The decrease in ball release speed observed during over seven was shown to be significantly (p<0.05) lower than overs one to four. Conclusion: The power output and perceived strain results of the players, appears to indicate the presence of fatigue in players. However, the results are not conclusive, as the fatigue was not shown in muscle recruitment patterns, as well as the body discomfort ratings. There was a non-significant trend observed in the lower limb muscle activation decreasing at higher speeds. Players were able to maintain accuracy. However, the significantly lower ball release speed observed during over seven showed players performance decreasing.

Taking a multi-disciplinary, integrated approach, the present study sought to examine selected physiological and psycho-physical parameters related to load carriage involving a 12 km march under military conditions. Military constraints hampered, but did not entirely inhibit the secondary aim of the study which concerned the effectiveness of relativising loads in order to normalise responses for all soldiers, irrespective of morphological diversity. Forty three subjects were measured in six groups using a test-retest experimental protocol. They were involved in a rest-broken 12 km march at 4 km.h⁻¹ under 40.5 kg absolute total load and under a relative load of 37% of body mass. Heart rates, ratings of perceived exertion (RPE) as well as area and intensity of discomfort were monitored for all subjects. Ten subjects were measured more extensively with regard to physiology using the Metamax, a portable ergospirometry system that provides all the data needed for a complete functional analysis of lung, heart, circulation and metabolic activity. Physiological responses (fc; fb; V̇T; V̇E; V̇O₂; EE; V̇CO₂; R; T°) indicated subjects were not severely physically taxed and that the loads imposed constituted a sub-maximal demand. Moreover, there appeared to be a limited cumulative effect over the 3.5 h. Data from the first and third hours were similar, while the significantly higher responses in the second hour reflected the challenge of the undulating terrain encountered during this section of the march. All responses during the Relative load conditions mirrored those of the Absolute load condition but, because the demands were less, the trends occurred at a reduced level. Furthermore, the reduction in inter-individual variability indicates that relativised load carriage tends to stress the soldiers in a more uniform manner. All "local" RPE responses were higher than "central" ratings, suggesting soldiers were in good cardiovascular condition and experienced marginally more strain in the lower limbs. There was increased perceived strain corresponding to the increase in gradient, with little cumulative effect over the three hours. The shoulders and feet were the two regions in which most discomfort was experienced; the shoulders being the worst area in the first hour and the feet being rated the worst after the third hour of marching. This study clearly demonstrates the probability of a significant improvement in mean combat-readiness following loaded marching by showing that, if loads are set at levels commensurate with individual capabilities to carry them without undue strain, unnecessary physical demands experienced by smaller, more gracile soldiers are reduced.

There is a prevalent assumption in the recognition memory literature that the terms “novelty” and “familiarity” are words ascribed to differing extremities of a single memory strength continuum. The aim of the current thesis was to integrate experimental methodologies across human and rodents to further investigate novelty processing at both a cognitive and neural level, and assess whether it is dissociable from familiarity processing. This dissociation was questioned at a cognitive level in human participants in Experiments 1 to 3 and at a neural level in rats in Experiment 4 and 5. Participants were found to differentially assess novelty and familiarity when making confidence judgements about the mnemonic status of an item (Experiment 1). Additionally, novelty and familiarity processing for questioned items were found to be dissimilarly affected by the presence of a concurrent item of varying mnemonic statuses (Experiment 2 and 3). The presence of a concurrent familiar item did not impact novelty processing in the perirhinal cortex (Experiment 4 and 5), yet disrupted the neural networks established to be differentially engaged by novelty and familiarity (Experiment 5). These findings challenge the assumption that the terms “novelty” and “familiarity” relate to a single recognition memory process. Finally, to allow integration of the findings from the human and rodent experiments, the relationship between measures or recognition memory obtained from spontaneous object recognition (SOR) task in rats and recognition memory measures estimated from signal-detection based models of recognition memory in humans was investigated (Experiment 6 and 7). This revealed that novelty preference in the SOR was positively correlated to measures of recognition memory sensitivity, but not bias. Thus, this thesis argues for the future inclusion of a novelty as a dissociable process from familiarity in our understanding of recognition memory, and for the integrations of experimental methodologies used to test recognition memory across species.

The purposes of this study were to (a) investigate the physiological changes produced in college men after a nine-week circuit training and jogging conditioning program, (b) analyze the effects of deconditioning periods of four, six, and eight weeks upon the physical fitness of college men, and (c) compare the developmental and retentive aspects of muscular strength, muscular endurance, circulo-respiratory endurance, and skinfold measurements. Pearson Product-Moment correlations of pre-test measures, post-test measures, differences between pre-test and post-test measures, and differences between post-test and respective retention test measures did not identify any consistent pattern of developmental or retentive relationships. The components of fitness tended to develop and deteriorate independently of each other.

Made available in DSpace on 2014-08-13T14:50:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-10Bitstream added on 2014-08-13T18:00:08Z : No. of bitstreams: 1 000764915.pdf: 1095983 bytes, checksum: ca335ee2eef246c7b39b45c9469611d7 (MD5) / A motivação pode ser considerada uma importante variável a ser estudada na área da Psicologia do Esporte, uma vez que esta influencia o indivíduo de diversas maneiras, tanto na sua vida pessoal, quanto no seu desempenho esportivo. Pensando em esporte, o atleta apresenta grande vulnerabilidade necessitando de um preparo físico e psicológico equilibrado. As lesões são fatores constantes e influentes no esporte podendo levar o atleta a abandonar a carreira. O objetivo desse estudo foi investigar a motivação de atletas de voleibol pós-lesionados de voleibol para voltarem a jogar. Foi realizada uma pesquisa netnográfica com 32 atletas de voleibol acima de 18 anos, com qualquer tipo de lesão que responderam o Inventário de Motivação para Prática de Atividade Física (IMPRAF 54). Foi realizado um método misto explanatório dos dados. Os resultados obtidos pelos atletas nas escalas demonstraram que estes estão mais motivados na dimensão prazer e saúde, tendo como hipótese por estes atletas estarem ou terem sofrido alguma lesão e terem maior interesse e preocupação com essas variáveis no momento. Quando as dimensões foram avaliadas separadamente, os itens variaram um pouco em cada dimensão. No grupo focal via Facebook, percebemos a importância do autoconhecimento e autorreflexão dos indivíduos e do trabalho em grupo. Podemos concluir que os atletas lesionados apresentam autoconceitos que foram construídos e assim dão valores as variáveis psicológicas, no presente estudo a motivação, de acordo com o que foi construído e vivenciado durante toda sua vida. No caso, os atletas apresentaram características semelhantes a outros estudos realizados e mesmo inseridos no contexto esportivo não estão preocupados em competir, podendo considerar a faixa etária que estes indivíduos se encontravam, a competição não ser uma variável motivacional tão significativa

Assessments of skeletal muscle functional capacity or bilateral muscular asymmetry often necessitate maximal contractile effort, which exacerbates muscle fatigue or injury. Tensiomyography (TMG) has been investigated in laboratory settings, as a means to assess muscle contractile function following fatigue; however observations have not been contextualised by concurrent physiological measures. TMG has more sparingly been applied in the field, with elite athletes. The aim of this thesis was to examine acute alterations and underlying variations in muscle contractile mechanics, through the application of TMG, contextualised with established physiological measures; and to apply TMG within high performance sports programmes. TMG successfully detected fatigue, evident from reduced strength, by displaying impaired muscle displacement, accompanied by elevated resting muscle tension. Greater asymmetry was detected in individuals with asymmetric strength; however, symmetry was masked during more complex tasks. Increased day-to-day variability was detected among highly trained athletes compared to recreationally active individuals. Acute training adaptations were detected, in contractile mechanics, in individual muscles. TMG could be useful in establishing fatigue status of skeletal muscle without exacerbating the functional decrements of the muscle, whilst also providing useful screening information for detecting asymmetry which may not be apparent during functional actions.

Orientador: Afonso Antonio Machado / Banca: Priscila Carneiro Valim-Rogatto / Banca: Flávio Rebustini / Resumo: A motivação pode ser considerada uma importante variável a ser estudada na área da Psicologia do Esporte, uma vez que esta influencia o indivíduo de diversas maneiras, tanto na sua vida pessoal, quanto no seu desempenho esportivo. Pensando em esporte, o atleta apresenta grande vulnerabilidade necessitando de um preparo físico e psicológico equilibrado. As lesões são fatores constantes e influentes no esporte podendo levar o atleta a abandonar a carreira. O objetivo desse estudo foi investigar a motivação de atletas de voleibol pós-lesionados de voleibol para voltarem a jogar. Foi realizada uma pesquisa netnográfica com 32 atletas de voleibol acima de 18 anos, com qualquer tipo de lesão que responderam o Inventário de Motivação para Prática de Atividade Física (IMPRAF 54). Foi realizado um método misto explanatório dos dados. Os resultados obtidos pelos atletas nas escalas demonstraram que estes estão mais motivados na dimensão prazer e saúde, tendo como hipótese por estes atletas estarem ou terem sofrido alguma lesão e terem maior interesse e preocupação com essas variáveis no momento. Quando as dimensões foram avaliadas separadamente, os itens variaram um pouco em cada dimensão. No grupo focal via Facebook, percebemos a importância do autoconhecimento e autorreflexão dos indivíduos e do trabalho em grupo. Podemos concluir que os atletas lesionados apresentam autoconceitos que foram construídos e assim dão valores as variáveis psicológicas, no presente estudo a motivação, de acordo com o que foi construído e vivenciado durante toda sua vida. No caso, os atletas apresentaram características semelhantes a outros estudos realizados e mesmo inseridos no contexto esportivo não estão preocupados em competir, podendo considerar a faixa etária que estes indivíduos se encontravam, a competição não ser uma variável motivacional tão significativa / Abstract: Not available / Mestre