Introduction: With batting in cricket, there is no known end point, making the allocation of resources and the development of a suitable pacing strategy more difficult. How batsmen allocate resources and pace themselves when repeatedly sprinting between the wickets is therefore not known. According to the ‘anticipatory feedback’ model, the level of expertise/experience has a substantial influence on the development of a suitable pacing strategy. Skilled or experienced batsmen may therefore have a greater ability to develop and implement a pacing strategy compared to that of novice or less-skilled batsmen. Purpose: To assess whether the absence of a known end point at the beginning of repeated sprint bouts between the wickets effects how batsmen pace themselves comparing skilled and less-skilled batsmen. Methods: Twenty-four male cricketers from a university league were selected. Twelve skilled batsmen (players in the top five batting order), and 12 less-skilled batsmen (players in the bottom five batting order) completed three experimental. All trials required batsmen to complete the same number of shuttle sprints (14 shuttles and therefore 28 runs), while only the information provided before each trial differed. Control Trial: This trial is also referred to as the ‘informed’ trial as the batsmen are aware of the exercise requirements (end point). Unknown Trial: The batsmen were not informed of the exercise end point and were required to run on command for an indefinite period (28 runs). Deceptive Trial: Batsmen’ were incorrectly informed with regards to the number of sprints (told they were only doing 14 runs when in fact they were doing 28 runs). Muscle activity, sprint times and RPE measures were obtained during all three trials and compared. Results: Significant (p<0.05) group effects were apparent for sprint times and, ‘central’ and ‘local’ RPE. Specifically, skilled batsmen obtained the faster mean sprint times, and less-skilled batsmen reported the higher mean ‘central’ and ‘local’ RPE values in all three experimental trials. There were no significant group effects for muscle activation. Skilled batsmen did however have lower muscle activation compared to less-skilled batsmen in all three trials. Furthermore, general trends revealed that sprint times and muscle activation decreased over time (from shuttle 1 to shuttle 14), and RPE (‘central’ and ‘local’) ratings increased, regardless of the experimental trials. Skilled batsmen performed the best in all three trials. This was determined by the attainment of faster sprint times, lower muscle activation and low RPE ratings in each of the three trials. The assessment of the relationship of the dependent variables measured in each trial, did however suggest that skilled batsmen performed best in the deceptive trial while less-skilled batsmen performed best in the control trial. Skilled batsmen thus showed superior performance when trial requirements were unclear. Less-skilled batsmen however, were seen to experience decrements in performance when information regarding the end point was unknown or misleading. Conclusion: It can thus be concluded that previous experience facilitates in the obtainment of improved sprint times between the wickets, especially when the exact end point is unknown.

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

Suboptimal preparation for the Ironman triathlon can have detrimental effects on mental and physical condition. The purpose of this longitudinal investigation was to examine the relationship between a number of performance changes and fatigue markers during training for an Ironman as well as immediately after the event, in an attempt to better understand the effects of ultraendurance training. Eighteen athletes training for the Ironman; South Africa, 2009 were recruited for the study. Over the 6 month data collection period body mass, training load (TRIMP and Session x RPE methods), physiological responses (waking heart rate, postural dizziness, sleep ratings), changes in psychological state (profile of mood states - POMS), reported immunological responses (symptoms of illness), biochemical changes (salivary cortisol and alpha amylase) and performance (8 km submaximal running time trial (TT) and race day performance) were measured. These responses were compared to a control sample (n=15). Results show a significant increase (p<0.05) in training load (3899.4 ± 2517.8) four weeks prior to the event. Fatigue scores significantly increased (p<0.05) concurrently with this significant increase (p<0.05) in training. TT performance did not significantly (p<0.05) alter during the time course of training. It was however strongly correlated to training load (R2=0.85) and modestly related to race performance (R2=0.65). The signs and symptoms of upper respiratory tract infections (URTI) were prevalent during the training period, decreasing during the taper and race period. Large standard deviations were found within the majority of the responses. During the final two weeks of preparation, tension scores were significantly increased (p<0.05) while training load significantly decreased (p<0.05) during the final week of preparation. Cortisol increased significantly (p<0.05) immediately post race (0.507±0.15<g.DL-1) and 1.5 hours later (0.796±0.23<g.DL-1). Overall the results indicate that the POMS questionnaire was a sensitive marker of fatigue and stress associated with ultraendurance training, and that the event itself placed a great deal of stress on the athletes which was illustrated by the post event measures.

M.Tech. (Chiropractic) / Purpose: Movement time is the time it takes an individual to perform an actual task. A faster and better movement can be invaluable in athletes using their upper limb. This study aims to see the immediate effect of a chiropractic adjustment on the segments innervating the upper limb, 05 to Ti spinal levels, to movement time in the upper limb, in athletes. Method: This study was a comparative study and consisted of two groups of fifteen. The participants were between the ages of eighteen and thirty five, with a half male to female ratio. The potential participants were examined and accepted according to the inclusion and exclusion criteria. The method of treatment administered to each participant was determined by group allocation. Group 1 received chiropractic adjustments to the segments innervating upper limb (C5-T1). Group 2 was the control group and did not receive treatment, only a rest period of ten minutes was given in between tests. Objective data findings were based on the above treatment protocols. Procedure: Treatment consisted of six treatment consultations with an additional follow up consultation over a three week period, with two consultations being performed per week interval. Objective data readings were taken at the beginning of the first, fourth and seventh consultations. Objective data was collected by the tapping task test and the movement time evaluator program. Analysis of collected data was performed by a statistician. The chiropractic adjustments used were based on restrictions identified during motion palpation and were applied on all the consultations. Results: Clinically significant results were found in group i, the treatment group. Showing a decrease in overall movement time, especially between visit i and visit 4, but also between visit 4 and visit 7. Group 2, the control group, showed a decrease in movement time before and after visit i, but this was only due to learning effect of performing the test for the second time. No statistical significance was found between visit 1 and visit 4 or visit 4 and visit 7.

Research indicates that eccentric exercise is associated with delayed onset of muscle soreness (DOMS). The symptoms associated with DOMS is similar to other inflammatory conditions e.g. pain, swelling and tissue damage. The DOMS as a reaction to the muscle damage is accompanied by changes in cytokines, leukocytes and other markers of inflammation. Prolonged exercise training without adequate rest and nutrition can lead to chronic inflammation and altered cytokine production patterns, which could result in overtraining. Methodology The study included actively participating marathon runners and consisted of two groups, a control group (n = 24 athletes) and an experimental group taking Traumeel S (n = 26 athletes), assigned in a double-blind fashion. Subjects made use of the treatment protocol for a period of seven days and followed their normal training program with no additional training. DOMS was induced on day eight when subjects ran downhill at 75% of peak treadmill running speed (PTRS) for 45 minutes at a gradient of –10% with ratings of perceived exertion (RPE), perceived pain (RPP) and heart rate was measured during the run. After the DOMS was induced subjects reported for blood samples for serum creatine kinase (CK), serum cortisol and a differential white blood cell count was taken at the same time for four days after DOMS was induced. Results The t-test for independent groups was used to determine the statistical differences between the two groups and for inter-group analysis. The results showed minor and predominantly insignificant changes in CK-, basophil-, eosinophil- and lymphocyte-counts. The cortisol levels in the treated group were higher compared to the placebo group at 48-, 72- and 96-hours post-exercise. The treated subjects’ mean monocyte count fell significantly on the first day of recovery and remained significantly lower for the four days post-exercise. Conclusions The increased cortisol concentrations can assist the immune system to shut of the acute inflammatory reaction associated with DOMS and in so doing reduce exercise induced muscle damage and inflammation. The decreased monocyte counts will reduce blood vessel permeability and swelling, fewer pain receptors will be stimulated because of lower PGE2 levels associated with decreased monocyte activation. Secondary, muscle damage that can amongst others be associated with increased monocytic activity, will be limited. Additional blood tests and performance testing are needed to confirm and substantiate the findings of the research. / Dissertation (MA (Human Movement Sciences)--University of Pretoria, 2007. / Biokinetics, Sport and Leisure Sciences / unrestricted

Experienced male marathon runners, 9 black and 10 white, with marathon times of 2 hours 45 minutes or faster, acted as subjects for the study, the purpose of which was to determine whether black runners are better suited to marathon running than whites. Body composition was determined by anthropometry. Maximal oxygen uptake (VO₂ max) and other physiological variables were measured during a continuous, speed-incremented treadmill protocol using a computer-aided data acquisition system. Subjects also ran a simulated marathon at 92.5% of the running speed at which the ventilatory threshold (VT) occurred. Physiological, gait and RPE variables were measured at 10 minute intervals during the marathon. Major findings are detailed below:- The VO₂, max averaged 60.4 ∓ 6.5 and 63.2 ∓ 2.9 mI. kg⁻¹.min⁻¹ in the black and white runners respectively and was highly correlated with best marathon race time (r = 0.86 and 0.85 respectively) and VT (r = 0.84 and 0.60 respectively) (p < 0.05). No significant differences existed between the groups in submaximal oxygen uptake (VO₂,) or % VO₂ max utilised at 16 km.hr⁻¹, but the estimated % VO₂ max utilised during a marathon race was higher in the black (89.0 ∓ 5.5%) than the white runners (81. 5 ∓ 3.1%) {p .( 0.05). The % VO₂ max utilised at 16 km.hr⁻¹ (84.8 ∓ 9.1 and 78.6 ∓ 5.8% in the black and white runners respectively) was significantly correlated with the % VO₂, max utilised while racing in the white (81.5 ∓ 3.1%) (r = 0.70) (p < 0.05), but not the black runners (89.0 ∓ 5.5%). The VT occurred at 82.7 ∓ 7.7 and 75.6 :∓ 6.2% VO₂; max in the black and white groups respectively (p < 0.05). Post-marathon blood lactic acid levels were lower in the black (1.30 ∓ 0.26 mmo1.l⁻¹) than the white runners (1.59 ∓ 0.20 mmol.l⁻¹). The respiratory exchange ratio (R) was higher in the blacks than whites when running at 16 km.hr ⁻¹ (1.03 ∓ 0.07 and 0.98 ∓ 0.03 respectively) and during the marathon (p < 0.05). There was no significant difference in pulmonary minute ventilation (Vı) between the groups, but breathing frequency (f) was higher in the black (59 ∓ 12 breaths.min⁻¹) than the white runners (45 ∓ 8 breaths. min⁻¹ ) and tidal volume (V⊤) lower in the black ( 1.33 ∓ 0.16 l.breath⁻¹) than the white runners (1.75 ∓ 0.36 I.breath⁻¹) during submaximal running at 16 km. hr⁻¹ (p < 0.05). The same trend was observed during the marathon run. During the time-course of the marathon f increased and V⊤ decreased In both groups (p < 0.05). Stroke volume decreased and heart rate increased In both groups during the time-course of the marathon (p< 0.05). Cardiac output was therefore maintained. Thermal responses were similar in the two groups. A significant increase in rectal temperature coincided with a decrease in skin temperature and may have been related to an increase in f (r = 0.86 and 0.67 in the blacks and whites respectively), H/R (r = 0.70 and 0.67 respectively) and "local" (leg) RPE (r = 0.84 and 0.82 respectively). It was concluded that black runners were able to run marathon races at a higher % VO₂ more than whites due to the blacks having lower blood lactic acid levels when running at a similar % VO₂ max. Given similar maximal oxygen uptakes, this would enable blacks to run faster. Cardiopulmonary adjustments occur during the time-course of a marathon which maintains Q and Vı

M. Tech (Department of Information and Communication Technology, Faculty of Applied and Computer Sciences) Vaal University of Technology. / The author addressed the need of parents, school teachers and athletic coaches to be able to assess the level of performance and to compare performances of individual athletes of either gender and in any age group. This was achieved by creating formulas for the following areas in track and field athletics: • Correctly set base standards for all events from the results of 5 year weighted average performances. • Use the base standards to determine comparative standards for all events in all age groups. • Define a function to compare male and female performances in all events. • For all events, generate tables with a range from 0 to 1000 as a comparative measurement. These formulae were created using data from international and national meetings. Different case studies were used for each of the areas and the results were evaluated using the data. In all four areas, it was possible to define hybrid functions with a confidence factor better than 99%. The final performance tables can be updated during revision periods (every 2 to 4 years) by using the national results for the last 5 years. These revisions will be required as implements, tracks and training methods change with time and this will then in turn influence the performances. This is evident from the continuous improvement of records in all events. These tables will not only assist coaches to improve training techniques but it will also facilitate team managers to improve team selections, and it will open the options of meeting organizers to arrange meetings using different formats. As this is a new and unique formulation for measuring performances at junior level in world athletics it can be used as a basis for future improvements in the field of comparative measurement for athletics. Using these tables at senior level it may assist to settle arguments of performance comparisons that are not addressed by the current tables used by the International Amateur Athletics Federation (IAAF). It will also avoid the use of different tables for the same events in standard track and field athletics compared to those used for combined event competitions. The author of the tables used by the IAAF has recognised this work as a new and unique development. Future development will include the automatic update of all functions and creation of tables for publication from a standard Windows® based application. A companion application, using the results from this research, will be developed. This application will address all the administration functions required to conduct a meeting. It will include the preparation for the meeting, capturing of results during the meeting and result reporting after the meeting.

No description available.