Athletes who participate in sports where performance relies on repeated high-intensity efforts could benefit from creatine (Cr) ingestion due to an increased ability to perform and recover from high-intensity exercise bouts either during training or competition. However, few studies exist which have investigated the effects of acute short-term Cr supplementation on appropriately simulated soccer-specific performance.Aims. To determine the reproducibility of a 90 minute soccer-specific performance test and to subsequently examine the effects of acute short-term Cr ingestion (1 week) on soccer-specific physical performance. Study design. Two experimental designs were adopted for this thesis. For study one, a test-retest design was used to determine the reliability and validity of the Ball-sport Endurance And Sprint Test (BEAST). Two trials of the BEAST were performed, separated by five to seven days. For study two, a randomised, triple-blind, placebo-controlled experimental design was adopted to determine the efficacy of acute short-term Cr supplementation (seven days) on soccer-specific performance, using the BEAST protocol.Methods. Twenty male amateur soccer players volunteered to participate in the study. For study one, the test-retest reliability of several soccer-specific performance measures obtained during a modified version of the BEAST was quantified using the standard error of measurement (Van Cutsem, Duchateau, & Hainaut) (or typical error) (Hopkins, 2000), coefficient of variation (CV), and Intraclass Correlation Coefficient (ICC). For study two, the cohort was split and subjects randomly allocated to one of two groups (Cr supplementation and Placebo) on a matched-pair basis. The Cr group (mean age 25.4 ± 4.5 years, mean body-mass 79.3 ± 10.5 kg) ingested 20 g of Cr and 8 g of glucose powder per day for seven days, whereas the placebo (mean age 26.7 ± 4.6 years, mean body-mass 80.8 ± 8.6 kg) group ingested 20 g of corn-flour and 8 g of glucose per day for seven days. The effects of acute short-term Cr supplementation were analysed by repeated measures ANOVA. In addition, effect sizes (ES) were calculated and entered with the associated p-value into Hopkins' spreadsheet for determination of the ES confidence limits (95%) and the chances that the true effect was substantial (i.e. ES ≥ 0.2). Clinical/practical inferences were made accordingly.Results. Study 1: The BEAST protocol had good reliability (high ICC values, relatively low coefficients of variation, low noise to signal ratios) and face validity (HR, VO2, distances covered, duration, and movements performed in the BEAST were all similar to those reported in actual soccer matches). Study 2: Performance of the four major physical measures (12 m sprint, 20 m sprint, circuit time and vertical jump) during the BEAST deteriorated during the second half relative to the first half for both Cr and placebo groups, indicating a fatigue effect associated with the protocol. HR and body-mass values also decreased for both groups during the 90 minute protocol. However, there was no statistically significant differences between the groups for these four measures or for body-mass, HR or VO2max values, suggesting Cr had no substantial effect (relative to placebo) on improving physical performance (or reducing fatigue). When the effects were assessed for the whole 90 minute BEAST protocol, all effects showed a negative trend and, correspondingly, the chances of a detrimental effect were greater than the chances of a beneficial effect.Conclusions: The 90 minute BEAST protocol had good reliability and face validity making it a suitable soccer simulation and performance protocol with which to investigate the effects of Cr supplementation on soccer performance. However, no significant (statistical or clinical) effects of acute short-term Cr supplementation on soccer performance were observed suggesting its potential use as an ergogenic aid for soccer players is questionable.

Robot soccer provides a fertile environment for the development of artificial intelligence techniques. Robot controls require high speed lower level reactive layers as well as higher level deliberative functions. This thesis focuses on a number of aspects in the robot soccer arena. Topics covered include boundary avoidance strategies, vision detection and the application of evolutionary learning to find fuzzy controllers for the control of mobile robot. A three input, two output controller using two angles and a distance as the input and producing two wheel velocity outputs, was developed using evolutionary learning. Current wheel velocities were excluded from the input. The controller produced was a coarse control permitting only either forward or reverse facing impact with the ball. A five input controller was developed which expanded upon the three input model by including the current wheel velocities as inputs. The controller allowed both forward and reverse facing impacts with the ball. A five input hierarchical three layer model was developed to reduce the number of rules to be learnt by an evolutionary algorithm. Its performance was the same as the five input model. Fuzzy clustering of evolved paths was limited by the information available from the paths. The information was sparse in many areas and did not produce a controller that could be used to control the robots. Research was also conducted on the derivation of simple obstacle avoidance strategies for robot soccer. A new decision region method for colour detection in the UV colour map to enable better detection of the robots using an overhead vision system. Experimental observations are given.

Thesis (M.A.)--Reformed Theological Seminary, 1985. / Includes bibliographical references (leaves 99-105).

<p>Muscle fatigue has always been of vital importance in most sports. A few possible factors have been reported to be the cause of muscular fatigue during high intensity exercise; depletion of glycogen, oxidative stress, disruption of contractile mechanisms and accumulation of metabolites. One of the theories of the cause of muscular fatigue, both in endurance and intermittent sports, is decreased pH levels due to increased concentration of H+ ions dissociated from lactic acid in muscle. Carnosine, a fairly unnoticed ergogenic aid, taken in the form of β-alanine has shown to potentially delay the onset of fatigue. Supplementation of β-alanine, would increase carnosine levels in muscle and may counteract the decrease in pH since carnosine functions as a H+ buffer. The purpose of the present study was to examine the effects of 8 weeks supplementation of β-alanine in distance runners and Swedish division four soccer players on aerobic capacity, intermittent recovery and muscular fatigue. The runners (n = 15) were tested in lactate profiling tests and the soccer players (n = 22) were tested in the Yo-Yo intermittent endurance test pre and post the 8-week test-period. The yo-yo test did not result in significant difference between the soccer players’ β-group and control-group (p = 0,29). Neither did the lactate test result in significant differences between the distance runners’ β-group and control-group in any of the five variables measured. However, a trend in difference was seen between groups in both velocity at lactate threshold (VLT) (p = 0,11) and recovery blood lactate (RBL) (p = 0,14) where the β-group had increased slightly from 16,8 ± 1,6 km/h to 17,0 ± 1,2 km/h in VLT and decreased from 4,5 ± 1,6 mmol∙L-1 to 3,1 ± 1,0 mmol∙L-1 in RBL. The results suggested that β-alanine may delay the onset of fatigue and improve performance in endurance sports such as running by increasing the removal of lactate acid from muscle.</p>

Thesis (M.S.)--University of North Carolina at Greensboro, 2006. / Title from PDF title page screen. Advisor: Diane Gill; submitted to the School of Health and Human Performance. Includes bibliographical references (p. 54-57).

<p>Sammanfattning</p><p>Syfte och frågeställningar</p><p>Syftet med uppsatsen är att undersöka de målchanser som skapades under cupspelet i VM 2006 och analysera vilka som var mest effektiva, d.v.s. oftast resulterade i mål och varför.</p><p>För att besvara syftet användes följande frågeställning:</p><p>• Vilka typer av målchanser leder oftast till mål och är därmed mest effektiva?</p><p>Metod</p><p>Studiens datainsamlingsmetod har varit observation av 16 fotbollsmatcher från världsmästerskapen i fotboll 2006. Matcherna är inspelade på DVD från SVT:s och TV4:s TV-sändningar. Varje målchans har analyserats och kategoriserats och förts in i ett analysschema bestående av tio kategorier. Exempel på kategorier är försvarsmisstag (målchans som uppkommer efter misstag från det försvarande laget), individuell prestation (spelare som skapar en målchans på egen hand) och fast situation (målchans som uppkommer efter hörnspark, frispark, indirekt frispark, straffspark eller inkast.).</p><p>Resultat</p><p>Totalt skapades 366 målchanser varav 31 ledde till mål. Den målchans som oftast gav mål procentuellt sett var försvarsmisstag med 20 %. Individuell prestation gav mål i 14 % av fallen och fast situation 13 %.</p><p>Slutsats</p><p>De slutsatser som går att dra av studien är att försvarsmisstag, individuell prestation och fast situation, oftast leder till flest mål procentuellt räknat. Dessa typer av målchanser är därmed de mest effektiva.</p>

Sammanfattning Syfte och frågeställningar Syftet med uppsatsen är att undersöka de målchanser som skapades under cupspelet i VM 2006 och analysera vilka som var mest effektiva, d.v.s. oftast resulterade i mål och varför. För att besvara syftet användes följande frågeställning: • Vilka typer av målchanser leder oftast till mål och är därmed mest effektiva? Metod Studiens datainsamlingsmetod har varit observation av 16 fotbollsmatcher från världsmästerskapen i fotboll 2006. Matcherna är inspelade på DVD från SVT:s och TV4:s TV-sändningar. Varje målchans har analyserats och kategoriserats och förts in i ett analysschema bestående av tio kategorier. Exempel på kategorier är försvarsmisstag (målchans som uppkommer efter misstag från det försvarande laget), individuell prestation (spelare som skapar en målchans på egen hand) och fast situation (målchans som uppkommer efter hörnspark, frispark, indirekt frispark, straffspark eller inkast.). Resultat Totalt skapades 366 målchanser varav 31 ledde till mål. Den målchans som oftast gav mål procentuellt sett var försvarsmisstag med 20 %. Individuell prestation gav mål i 14 % av fallen och fast situation 13 %. Slutsats De slutsatser som går att dra av studien är att försvarsmisstag, individuell prestation och fast situation, oftast leder till flest mål procentuellt räknat. Dessa typer av målchanser är därmed de mest effektiva.

Muscle fatigue has always been of vital importance in most sports. A few possible factors have been reported to be the cause of muscular fatigue during high intensity exercise; depletion of glycogen, oxidative stress, disruption of contractile mechanisms and accumulation of metabolites. One of the theories of the cause of muscular fatigue, both in endurance and intermittent sports, is decreased pH levels due to increased concentration of H+ ions dissociated from lactic acid in muscle. Carnosine, a fairly unnoticed ergogenic aid, taken in the form of β-alanine has shown to potentially delay the onset of fatigue. Supplementation of β-alanine, would increase carnosine levels in muscle and may counteract the decrease in pH since carnosine functions as a H+ buffer. The purpose of the present study was to examine the effects of 8 weeks supplementation of β-alanine in distance runners and Swedish division four soccer players on aerobic capacity, intermittent recovery and muscular fatigue. The runners (n = 15) were tested in lactate profiling tests and the soccer players (n = 22) were tested in the Yo-Yo intermittent endurance test pre and post the 8-week test-period. The yo-yo test did not result in significant difference between the soccer players’ β-group and control-group (p = 0,29). Neither did the lactate test result in significant differences between the distance runners’ β-group and control-group in any of the five variables measured. However, a trend in difference was seen between groups in both velocity at lactate threshold (VLT) (p = 0,11) and recovery blood lactate (RBL) (p = 0,14) where the β-group had increased slightly from 16,8 ± 1,6 km/h to 17,0 ± 1,2 km/h in VLT and decreased from 4,5 ± 1,6 mmol∙L-1 to 3,1 ± 1,0 mmol∙L-1 in RBL. The results suggested that β-alanine may delay the onset of fatigue and improve performance in endurance sports such as running by increasing the removal of lactate acid from muscle.

Fotbollsdomare utsätts för en mängd olika stressorer. De använder sig av olika copingstrategier för att klara av dessa. Domare får utstå både knuffar, sparkar, slag och dödshot. Motivationen till att trots allt fortsätta döma har visat sig ligga i kärleken till sporten. Det saknas dock kvalitativ forskning inom området. Syftet var att undersöka fotbollsdomares upplevelser och hantering av kritik samt vad som motiverar dem att fortsätta. En intervjuundersökning genomfördes med åtta fotbolldomare. Resultatet gav nya insikter som visade att domare upplever kritiken de möter som träffande, förföljande, utsättande, ångestfull, påhoppande samt gav dem prestationskrav. Man hanterar kritiken genom att ta in viss kritik och undvikande av konflikter. Det som motiverade dem var att ta ansvar, hög strävan, glädje och inspiration. Att inte avancera i seriesystemet fick dem att tappa motivation. Domarna använde sig inte av mentala förberedelser inför match. Mentala förberedelser kan kanske underlätta för domare i sin arbetssituation.

Thesis (M.A.)--York University, 2007. Graduate Programme in Geography. / Typescript. Includes bibliographical references (leaves 197-205). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR29294