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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effects of caffeine supplementation on Women's National League soccer players' performance

Burke, Niamh R. January 2016 (has links)
Purpose: To determine the effects of acute caffeine ingestion on female soccer players repeated-sprint performance, time to exhaustion, heart-rate, and rating of perceived exertion. Additionally, to investigate if habitual caffeine consumption effects supplementation results. Methods: Using a randomised double-blind research design, 18 females from the Women’s National League ingested two-tablets containing either caffeine (400 mg) or placebo (lactose) 1 hour before completing an indoor multiple-sprint test (12 x 30 metre; separated by 35 seconds rest), and a multi-stage fitness test (Yo-Yo Intermittent Recovery Test Level 2). Participants attended two-testing sessions 7-days apart and consumed either placebo or caffeine on the first session, and the opposite on the second testing session. Sprint-times were recorded using dual-beam photocells, time to exhaustion was measured in seconds and metres covered using interval recording on paper. Heart rate was monitored continuously, while RPE was measured after every third-sprint and every-minute during the multi-stage fitness test. Results: Sprint 3, 4, and 5 in the multiple-sprint test showed significant results (three sprints p=0.001, sprint 3: caffeine 7.58±1.36, placebo 7.61±1.33, sprint 4: caffeine 7.54±1.35, placebo 7.60±1.31, sprint 5: caffeine 7.56±1.36, placebo 7.60±1.32), while sprint 8 and 9 showed a tendency for faster times. Time to exhaustion was significantly improved with caffeine (p=0.0001, caffeine 428±209 seconds, placebo 345±122 seconds), heart-rate was not significantly different between trials as no interaction effect was found between trials (p=0.183), RPE overall wasn’t statistically different between trials (all values were p > 0.005) with sprint 12 providing the only significant different rating of perceived exertion score (p=0.003, placebo 16.3±0.8, caffeine 15.7±0.9). Finally, habitual caffeine consumption wasn’t statistically different between conditions (time to exhaustion p=0.92, rating of perceived exertion p > 0.005, heart-rate p > 0.01, and multiple sprints p > 0.004). Conclusion: Caffeine supplementation improves female soccer performance by means of increased time to exhaustion, tendency to improve multiple-sprint performance, and doesn’t affect heart-rate. Caffeine does not affect rating of perceived exertion, however, due to the increase in performance seen it is thought that unchanged RPE allows the body to work at higher intensities for longer. Finally, habitual caffeine consumption does not affect results as long as an abstention period of 48 hours is undertaken prior to matches. Take home message: Caffeine in a 400mg dose positively effects female soccer performance and minimal health risks or negative effects are associated with this supplementation. Caffeine produces a huge positive increase in endurance capacity, such as time to exhaustion, while also increasing the ability to perform at higher intensities for longer, reduced perception of effort.
2

Monitoring fatigue status in elite soccer players

Thorpe, R. T. January 2016 (has links)
The physical demands of soccer players competing in the English Premier League have significantly increased in recent years (Barnes et al. 2014; Bush et al. 2015). Elite soccer players are required to compete on a weekly and often bi-weekly basis during a 9-month competitive season. During periods of fixture congestion, players may participate in three matches within a 7-day period. Previous researchers have reported that some components of performance and physiological measures may still be below a pre-match baseline 72 hours following match-play (Mohr et al., 2003; Andersson et al., 2008; Ispirlidis et al., 2008; Fatouros et al., 2010). Nevertheless, data are sparse for the quantification of player fatigue status during competitive periods. Therefore, the primary aim of this thesis is to evaluate potential indicators of fatigue which may be easily measured and utilised in elite soccer. The aim of the first study (Chapter 4) was to quantify the test-retest reliability of a range of potential fatigue variables in elite soccer players. During the pre-season period, resting perceived ratings of wellness (fatigue, muscle soreness, sleep quality and stress), counter-movement jump height (CMJ), sub-maximal heart rate (HRex), post-exercise heart rate recovery (HRRbpm and HRR%), heart rate variability (rMSSD and LnrMSSD) and salivary immunoglobulin-A (S-IgA) were measured during the morning on two consecutive non-training days in thirty-five English Premiership players. Mean values of perceived ratings of wellness (7-13 %CV), CMJ (4 %CV) HRex (3 %CV) and HRR% (10 %CV) were not substantially or statistically significantly different between days. HRV measures’ rMSSD (28 %CV) and Ln rMSSD (10 %CV), perceived ratings of sleep (CV 13%CV) and S-IgA (63 %CV) were statistically significantly different between days. All morning-measured fatigue variables with the exception of S-IgA were reliable enough to allow feasible sample sizes in future pre/post studies. These data indicate that the use of perceived ratings of wellness, CMJ, HRR%, and, to a certain extent, HRV (Ln rMSSD) are reliable enough to monitor the fatigue status of a sample of elite soccer players. The aim of the second study (Chapter 5) was to quantify the relationship between daily training load and a range of potential measures of fatigue in elite soccer players during an in-season competitive phase (17-days). Total high-intensity running (THIR) distance, perceived ratings of wellness (fatigue, muscle soreness, sleep quality), CMJ, HRex, HRR% and heart rate variability (Ln rMSSD) were analysed during an in-season competitive period (17 days). Within-subject fluctuations in fatigue (r=-0.51; large; P<0.001), Ln rMSSD (r=-0.24; small; P=0.04), and CMJ (r=0.23; small; P=0.04) were significantly correlated with fluctuations in THIR distance over the study period. Correlations between variability in perceived muscle soreness and sleep quality and HRR% and THIR distance were negligible and not statistically significant. Perceived ratings of fatigue and heart rate variability were sensitive to daily fluctuations in THIR distance in a sample of elite soccer players. Therefore, these specific markers show particular promise as simple, non-invasive assessments of fatigue status in elite soccer players during a short in-season competitive phase. The aim of the third study (Chapter 6) was to determine whether the sensitivity of a range of potential fatigue measures studied in Chapter 5 would be improved compared with the training load accumulated over the previous two, three or four days during a short in-season competitive period (17-days). Fluctuations in fatigue (r=-0.28-0.51; “small” to “large”; p<0.05) were correlated with fluctuations in THIR distance accumulation (1-4-day). Changes in HRex (r=0.28; small; p= 0.02) was correlated with changes in 4-day THIR distance accumulation. Fluctuations in Ln rMSSD (r=-0.24; small; P=0.04), and CMJ (r=0.23; small; P=0.04) were only sensitive to changes in THIR distance for the previous day (Chapter 5). Correlations between variability in muscle soreness, sleep quality and HRR% and THIR distance were negligible and not statistically significant for all accumulation training loads. Perceived ratings of fatigue were sensitive to daily fluctuations in acute THIR distance accumulation although sensitivity attenuated over time. Therefore, the present findings indicate that the sensitivity of morning-measured fatigue measures to changes in training load is not improved when compared with training loads beyond the previous days training. The fourth and final aim of the thesis was to quantify the mean daily changes in training load and parallel changes in measures of fatigue across typical in-season training weeks in elite soccer players. The training load of 29 elite soccer players was measured using the ratings of perceived exertion approach. Perceived ratings of wellness (fatigue, sleep quality and muscle soreness), sub-maximal heart rate (HRex), post-exercise heart rate recovery (HRR) and variability (HRV) were also recorded across training weeks in the in-season competitive period. Morning-measured perceived ratings of fatigue, sleep quality and muscle soreness tracked the changes in RPE-TL, being 35-40% worse on post-match day vs pre-match day (P<0.001). Perceived fatigue, sleep quality and muscle soreness improved by 17-26% from post-match day to three days post-match with further smaller (7-14%) improvements occurring between four days post-match and pre-match day (P<0.01). There were no substantial or statistically significant changes in HRex, HRR% and HRV over the weekly cycle (P>0.05). Morning-measured perceived ratings of fatigue, sleep quality and muscle soreness are clearly more sensitive than HR-derived indices to the daily fluctuations in session load experienced by elite soccer players within a standard in-season week. The results of this thesis have shown that simple, ratings of perceived wellness are reliable and sensitive to short training and competition phases and thus may be a suitable strategy for practitioners to use in the attempt to establish fatigue status in elite soccer players. In particular, this thesis has demonstrated that the greatest sensitivity was observed on a daily basis and during typical training weeks and not during short term load accumulation. . Future work is required to quantify whether perceived ratings of wellness and vagal-related heart rate responses are sensitive to changes in training and match load across an entire competitive season in elite soccer players.
3

Kvinnliga och manliga elitfotbollsspelares fotbollskonsumtion i Sverige / Female and male elite soccer players soccer consumption in Sweden

Elger, Jesper, Jönsson, Annie January 2023 (has links)
Authors: Elger, Jesper &amp; Jönsson, Annie  Advisor: Svensson, Daniel  Keywords: Consumption, Soccer/football, Femininity, Gender identities, Norms.  Purpose: The purpose of this study, based on a quantitative method is to investigate differences and similarities regarding football consumption in female and male elite football players in Sweden.   Method: The study is based on a deductive approach, which means that we have worked with already existing theoretical material and thereafter collected our own empirical data. Empirical data were collected through a questionnaire that was sent out to five different elite football clubs in Sweden.  Theory: The study is based on Hirdman's theory of the gender contract, as well as Lamont and Molnár's theory of boundaries.  Results and conclusion: With help from the questionnaire that was sent out to five different elite football clubs in Sweden the study can display an overall result regarding football consumption by female and male elite players. The overall result indicates that there were no significant differences and similarities regarding football consumption within five elite clubs in Sweden. The result in the study presents no significant differences and similarities regarding consumption of football but there is still an ability to draw conclusions with help from a theoretical framework based on Hirdman´s and Lamont´s Molnár´s theory. The final conclusion of this study was that there are many similarities between female and male elite football players' football consumption. The study's results and theories allow an argument regarding female and male football consumption. In addition to the fact that the majority on both the men's and women's side consume football primarily because the players "think it's fun", it is argued that there may be additional reasons for the players' individual consumption. This study reveals two reasons why Hirdman's gender contract does not have such a large impact regarding gender, elite soccer players and soccer consumption. The first reason is that men are standard bearers in both society and football, and that women have adapted to these standards, in this case to consume football, which is "manly". The second reason is that the boundaries have been changed in various ways, as described based on Lamont's and Molnár's theory. However, one does not necessarily exclude the other, but can work together.
4

Environmental stressors and cooling interventions on simulated soccer performance

Aldous, Jeffrey William Frederick January 2016 (has links)
The increasing globalization of elite soccer match-play means that soccer players are likely to compete in hot, hypoxic and hot-hypoxic environments over a season. Soccer match-play studies have identified a marked decline in soccer-specific physical performance in the heat and hypoxia due to increasing body temperatures and a reduction in partial pressure of oxygen (PO2), respectively. As hot environments are more prevalent in elite soccer match-play, cooling strategies have been assessed within the literature in an attempt to alleviate these heat-induced- decrements. However, utilising a soccer match-play design makes environmental and interventional inferences difficult to ascertain, as a plethora of match factors and adaptive pacing strategies cause high variability in key physical performance measures within soccer match-play. Therefore, the three experiments within thesis aimed to assess the reliability and validity of a non-motorised treadmill (NMT) based soccer-specific simulation [intermittent Soccer Performance Test - (iSPT)], to enable the reliable investigation of environmental stress on soccer performance and the efficacy of pre- and half-time-cooling to attenuate any heat- induced-decrements. The purpose of experiment 1 was to investigate the reliability and validity of iSPT which utilised a novel speed component called a ‘variable run’. This speed component quantified the distance covered at a self-selected speed above the second ventilatory threshold (VT2speed), which attempted to delimit a ‘high-intensity’ threshold. Twenty male University soccer players completed one maximal oxygen (O2) uptake (V̇ O2max ) test, three familiarisation (FAM) sessions and one peak speed assessment (PSA) on the NMT, before completing the iSPT twice (iSPT1 and iSPT2). The total distance, sprint distance and high-speed distance covered were 8,952 ± 476 m, 1,000 ± 74 m and 2156 ± 140 m, respectively. No significant difference (p>0.05) was found between repeated trials of the iSPT for all physical performance measures and physiological responses. Reliability measures between iSPT1 and iSPT2 showed good agreement [Coefficient of variation: <4.6%; Intraclass correlation: >0.80] compared with statistical guidelines. Furthermore, the variable run phase showed high speed running capacity was significantly decreased (p<0.05) in the last 15 min compared to the first 15 min, showing parity with previous match-play data. Experiment 1 validated the iSPT as a NMT based soccer- specific simulation compared to previous match-play data, and is a reliable tool for assessing and monitoring the physical performance and physiological responses in soccer players. Successfully completing the aim of experiment 1 facilitated the quantification of hot (HOT), hypoxia (HYP) and hot-hypoxia (HH) mediated decrements on maximal soccer-specific performance in experiment 2. Twelve male University soccer players completed three FAM sessions, one PSA and four randomised crossover experimental trials of the intermittent Soccer Performance Test (iSPT) in normoxic-temperate (CON: 18oC 50% rH), HOT (30oC; 50% rH), HYP (1,000m; 18oC 50% rH) and HH (1,000m; 30oC; 50% rH). Physical performance and its performance decrements, body temperatures [rectal (Tre), skin (Tsk) and estimated muscle temperature (Tmu)], heart rate (HR), arterial blood oxygen saturation (SaO2), perceived exertion, thermal sensation (TS), body mass changes, blood lactate (Bla) and plasma volume were all measured. Performance decrements were similar in HOT and HYP [total distance (-4%), high- speed distance (~-8%) and variable run distance (~-12%) covered] and exacerbated in HH [total distance (-9%), high-speed distance (-15%) and variable run distance (-15%)] compared to CON. A 4% increase in peak sprint speed was present in HOT compared with CON and HYP and 7% greater in HH. The sprint distance covered was unchanged (p > 0.05) in HOT and HYP and only decreased in HH (-8%) compared with CON. Body mass (-2%), temperatures (+2- 5%) and TS (+18%) were altered in HOT. Furthermore, SaO2 (-8%) and HR (+3%) were changed in HYP. Similar changes in body mass and temperatures, HR, TS and SaO2 were evident in HH compared to HOT and HYP, however, Bla (p < 0.001) and plasma volume (p <0.001) were only significantly altered in HH. Perceived exertion was elevated (p < 0.05) by 7% in all conditions compared with CON. Regression analysis identified that absolute TS and absolute rise in Tsk and estimated Tmu (r = 0.82, r = 0.84 r = 0.82, respectively; p <0.05) predicted the hot-mediated-decrements in HOT. The hot, hypoxic and hot-hypoxic environments impaired physical performance during iSPT. Future interventions should address the increases in TS and body temperatures, to attenuate these decrements in physical performance. Experiment 3 of this thesis aimed to identify three pre- and half-time-cooling strategies to attenuate the heat-induced-decrements previously seen in experiment 2. Eight male University soccer players completed four randomised experimental trials of iSPT, three with cooling and one control (i.e. No pre- or half-time cooling: CON). The pre- and half-time-cooling interventions involved were 30-min or 15 min in duration, respectively. Ice slurry ingestion (SLURRY), ice packs (PACKS) covering the upper legs and mixed-methods (MM: PACKS and SLURRY) were utilised as the three cooling interventions. Physical performance and its performance decrements, body temperatures (Tre, Tsk and estimated Tmu), HR, perceived exertion, TS, body mass changes and Bla were all measured. Compared with CON, both PACKS and SLURRY pre-cooling significantly reduced (p > 0.05) central (Tre) and peripheral (Tsk and estimated Tmu) body temperatures prior to iSPT, respectively. However, body temperature and physical performance were unchanged during the first half of PACKS and SLURRY compared with CON. The MM pre-cooling significantly reduced all body temperatures and TS both prior to and during the first half which coincided with an improvement in total distance (+3%), high-speed distance (+4%) and variable run distance (+5%) covered. Half-time-cooling via PACKS, SLURRY and MM had no ergogenic effect (p> 0.05) upon physical performance in the second half, compared with CON. The 30 min of mixed-method pre-cooling, via ice packs placed upon the upper legs and ice slurry ingestion, significantly improved simulated soccer performance during the first half, however, future research should identify a valid half-time-cooling strategy to offer further improvements to physical performance in the second half. The main findings within this thesis revealed that the iSPT showed validity with previous soccer match-play data and strong reproducibility between two tests (iSPT1 and iSPT2). Furthermore, the variable run component showed efficacy as sensitive measure of the decrements in high-speed running capability. As the iSPT demonstrated low test-retest error compared with the statistical guidelines and previous NMT based soccer-specific simulations, any changes to physical performance can be attributed to an intervention and not the variability of the measure, unlike in soccer match-play situations. No difference was seen for all physical performance measures in both HOT and HYP, however, the heat and hypoxic-induced- decrements stem from increasing body temperatures and changes to both SaO2 and HR, respectively. Such decrements may have a detrimental effect upon the match outcome. These heat-induced-decrements were attenuated in the first half after 30 min of mixed-methods pre- cooling, however, the 15 min of mixed-methods half-time-cooling did not significantly improve any physical performance measure in the second half. The mixed-method pre-cooling strategy tested within this thesis could go some way in maintaining physical performance during the first half of soccer match-play in hot environments (~30oC). However, future laboratory based research within a controlled environment should look to assess different combinations, times and strategies of cooling which may be applicable to the time constraints associated with elite soccer.
5

O processo de projeto da experiência do torcedor em estádios de futebol sob a ótica do design estratégico : um estudo de caso do Sport Club Internacional

Vilela, Ana Carolina Fajardo 11 April 2011 (has links)
Submitted by Mariana Dornelles Vargas (marianadv) on 2015-05-20T18:51:56Z No. of bitstreams: 1 processo_projeto.pdf: 4851335 bytes, checksum: 026fa5fae274a56075c9d4ed9cfb483a (MD5) / Made available in DSpace on 2015-05-20T18:51:56Z (GMT). No. of bitstreams: 1 processo_projeto.pdf: 4851335 bytes, checksum: 026fa5fae274a56075c9d4ed9cfb483a (MD5) Previous issue date: 2011-04-11 / Nenhuma / O presente estudo busca discutir os conceitos de Design em um contexto peculiar de consumo, do futebol. Limita-se, nesse sentido, a analisar como foi o processo de projeto da experiência do torcedor no estádio de futebol sob a ótica do Design Estratégico, a partir do caso do Sport Club Internacional de Porto Alegre. Para tanto, adotou-se o estudo de caso como metodologia de pesquisa, incluindo também a revisão bibliográfica. Foram aplicadas entrevistas com os realizadores do projeto de modernização do estádio Beira-Rio. Os resultados obtidos permitem avaliar que algumas etapas do caso analisado são compatíveis com os conceitos apresentados pelo Design Estratégico. Entretanto, percebe-se a oportunidade para a utilização da atividade metaprojetual como instrumento para a concepção de produtos e serviços inovadores. Além disso, evidencia-se a relação positiva entre design e a experiência do usuário. Estabelece-se, assim, o Design para Experiência como uma ferramenta que qualifica e propicia experiências únicas e memoráveis para os consumidores. / This study discusses the concepts of Design in a peculiar consumption context, namely, soccer. This study thus limits itself to the examination of the design process of fan experience in the football stadium, from the perspective of Strategic Design and based on the Sport Club Internacional of Porto Alegre case. To this end, the case-study was the adopted research methodology, as well as a review of literature. Interviews were applied to the main actors involved in the Beira-Rio stadium renovation project. The results indicate that some stages from the case in question are compatible with Strategic Design concepts. However, there is also an opportunity for the use of metadesign as a tool for the conception of innovative products and services. In addition, the positive relationship between design and user experience is evinced. Accordingly, Design for Experience is established as a tool that qualifies and affords unique and memorable experiences for consumers.
6

Vad är det viktigaste i pojkars utveckling inom fotboll? : Ur ett miljöperspektiv

Johansson, Martin, Wahlman, Anders January 2015 (has links)
Syfte Syftet med uppsatsen är att försöka få reda på ny kunskap om vad som kan vara den optimala miljön för en fotbollsspelare på pojksidan. Tanken med studien är också att jämföra hur kulturen i Stockholm och Halmstad ser ut gällande prestige, högsta serie, selektering, specialisering, föräldrar, värdering av att vinna i ung ålder, tränarens roll, faciliteter och vad har föreningarna för möjlighet gällande träningstimmar (bilaga 4). Dessa faktorer kan vara avgörande i varje individs utveckling. Frågeställningar Vad är en optimal miljö för en pojkfotbollsspelare att utvecklas i? Vad är skillnaderna och likheterna mellan miljön i Stockholm och Halmstad? Metod Detta är en kvalitativ studie bestående av intervjuer med en semistrukturell intervjuguide. Tre spelare från Stockholm och tre spelare från Halmstad har intervjuats och de svar som framkommit har analyserats och diskuterats med hjälp av tidigare forskning inom ämnena: faciliteter, familj, tränare, filosofi &amp; kultur, skador, status i skola och nyckeln till framgång. Resultat Resultaten visade på att alla individer är olika, och att det som hjälper en person att slå igenom och ta sig till landslaget kanske inte fungerar för en annan. Flertalet intervjupersoner har lyft familjen som den viktigaste faktorn för att de ska ha lyckats, medan andra har lyft fram deras inre motivation som den avgörande faktorn för deras fotbollsspelande. Gällande plantider så fanns det betydligt fler i Halmstad än i Stockholm sommartid, men under vintern så var det Stockholm som hade flest tider och detta berodde på tillgängligheten till konstgräsplaner. Slutsats I studien så har svaren från intervjupersonerna analyserats och mikrosystemet var den delen som ansågs vara viktigast av stegen ur utvecklingsekologin. Då genom att du måste känna en trygghet i den närmiljö du har. Att hela tiden känna att du kan lita på någon och få feedback från dessa personer. Detta kan både fälla eller stärka en spelare. Vissa spelare passar bättre in med mer regler medan andra passar in med fria tyglar. Här gäller det för spelarna att hitta sin egna väg att gå. De andra nivåerna påverkar givetvis också människan, men i den här studien fann vi mikronivån den viktigaste nivån.

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