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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.
91

Culture and the Social Elements of Playing Exergames : an Exploratory Study

Carlberg, Lovisa January 2021 (has links)
Involving whole-body movements into the way games are played can provide various experiences for players, especially when the gameplay requires social interactions together with other players. In addition, a person’s cultural background influences the way they look at themselves in relation to others and how they communicate. Therefore, this thesis will explore what social elements in games involving physical activity are important to consider when designing for different cultural patterns. The research was conducted using a mixed-method approach by collecting quantitative data from an online survey and qualitative data from interviews together with associates at a golf game company. The findings show that the social environment and relationship between players influence the motivation for playing different kinds of games that require physical movements. However, understanding and measuring culture can be a great challenge and the results open up for discussion about directions for future research. / Att involvera rörelser med hela kroppen i hur spel spelas kan ge olika spelupplevelser, särskilt när spelet kräver sociala interaktioner tillsammans med andra spelare. Dessutom påverkar en persons kulturella bakgrund hur de ser på sig själva i förhållande till andra samt hur de kommunicerar. Därför kommer denna studie att undersöka vilka sociala element är viktiga att tänka på när man utformar spel som involverar fysisk aktivitet baserat på olika kulturella mönster. Metoden bestod utav att både en insamling av kvantitativa data genom en enkätundersökning online samt kvalitativa data baserat på intervjuer tillsammans med medarbetare på ett företag som utvecklar golfspel. Resultaten visar att den sociala miljön och förhållandet mellan spelare påverkar deras motivation för att spela olika typer av spel som kräver fysiska rörelser. Att förstå och mäta kultur kan dock vara en stor utmaning och resultaten öppnar därför upp en diskussion om riktningar för framtida forskning.
92

Spacesuit and Portable Life Support System Center of Gravity Influence on Astronaut Kinematics, Exertion and Efficiency

Sridhar, Siddharth January 2015 (has links)
No description available.
93

Effects of self-control training and brain endurance training on endurance performance and ratings of perceived exertion

Trafford, Daniel 11 1900 (has links)
Self-Control Training (SCT) and Brain Endurance Training (BET) are novel training modalities designed to enhance physical endurance by building fatigue resiliency. Despite their similarities, it has yet to be examined whether combining SCT and BET provides an additive or redundant/overlapping effect on endurance exercise performance. This study investigated the effects of SCT and combined SCT+BET on performance of a maximal exertion isometric resistance endurance task (high plank) and ratings of perceived exertion (RPE). Participants (N = 33) were randomized to engage in 4 weeks (18 training sessions) of SCT (isometric handgrip; n = 13), SCT+BET (10-minute cognitively demanding task, followed by SCT; n = 10), or no-training/control (n = 10). Isometric endurance performance trials were completed at pre-, mid-, and post-training. One-way analysis of covariance (ANCOVA) models were computed for each of the mid- and post-training trials (controlling for pre-training high-plank performance) to assess effects on performance. Results showed no significant effects of training on high plank performance between groups at mid-training; however, a large and significant effect for SCT compared to control was observed at post-training (p = .044, d = .961). No significant main effects or interaction effects were found for changes in RPE over time (p’s > .05). Findings support the use of SCT as an effective training method for physical endurance performance and suggest that BET may not offer additional performance benefit compared to SCT under the training and testing conditions used in this protocol. Future research should explore potential dose-response effects of SCT on performance and moderators such as trait self-control. / Thesis / Master of Science (MSc)
94

Effects of Tool Weight on Fatigue and Performance During Short Cycle Overhead Work Operations

Kirst, Margaret Anne 31 December 1999 (has links)
This study is a subset of a larger body of research that examined shoulder time to fatigue during overhead work in an attempt to reduce the prevalence and impact of work-related musculoskeletal problems in the shoulder associated with overhead work, particularly during automobile assembly. Existing evidence suggests that shoulder injuries are diverse in terms of tissues affected and symptoms presented. Furthermore, the cause of these injuries is multifactorial. The work presented here assumes that musculoskeletal injuries of the shoulder mechanism are at least related to, if not caused by, fatigue localized to the shoulder musculature. While the exact relationship between fatigue and injury has not been clearly established, there is consensus among researchers that fatigue plays and important role. Muscular fatigue, therefore, is viewed as a surrogate measure of risk, and task design to avoid fatigue is seen as a rational method to minimize this risk. An experiment to determine the effects of tool weight on shoulder fatigue and performance during overhead work with work/rest cycles was performed. Times to fatigue were derived based on dependent measures including total task duration, controlled maximum muscle contractions, subjective ratings based on Borg's CR-10 RPE scale, electromyogram behavior (MdPF), and hand force performance measures. Experimental findings indicated that duty cycle (percentage of total task cycle time spent working) significantly affected task duration (p<0.0001), changes in maximum voluntary contraction values for the infraspinatus (p<0.05), and the minimum time for any shoulder muscle to fatigue as determined by changes in the EMG power spectrum (p<0.05). Time to fatigue for the mid deltoid as determined by changes in the median frequency of the EMG power spectrum was shown to change significantly (p<0.05) with change in tool weight. Large intersubject variation was observed for the dependent measures, which showed subjects experiencing different levels of fatigue while performing the same task. Limitations of the study and recommendations for future direction are also discussed. / Master of Science
95

Effects of Work Exposure on Maximum Acceptable Repetition Rates in a Manual Torquing Task

Kant, Ravi 30 August 2007 (has links)
Repetitive and forceful exertions have been dentified as an important risk factor for occupational injuries. One method used to determine appropriate exposures to these and other risk factors is psychophysics, which is based on individual perceptions of task demands and/or risk. Effects of work exposure have been indicated as of potential importance, but have not been well studied. Indications from an earlier study related to psychophysical limits for a repetitive manual torquing task were that five days of work conditioning had minimal effects on resulting Maximum Acceptable Repetition Rates (MARR). However, it is unknown whether and how longer work exposure durations might influence MARRs. The current study investigated the effects of work exposure on MARR and adjustment time over 10 working days (two weeks) with two days of rest after five days. Ten participants (five males and five females) performed a manual torquing (45 Nm load) task at mid-chest level in the coronal plane for a one hour test session. Starting repetition rate for each participant was set at single high and low rate on alternate days. Temporal (exposure) effects were determined, where day of exposure was the independent variable, and MARR and adjustment time were the dependent variables. Final MARRs were relatively lower during the first few exposure days (14 - 15 repetitions/min) and increased for days 5 - 7 (16 - 18 repetitions/min). On average participants made four adjustments to reach MARR . Day was not found to significantly affect MARR, though week affected both MARR and adjustment time. Thus, an exposure of two weeks may be needed to obtain stable and valid psychophysical limits for manual torquing and, perhaps, related tasks. / Master of Science
96

Expressão e seleção de microRNAs no músculo esquelético de homens saudáveis submetidos ao treinamento físico aeróbio\" / MicroRNA-206 skeletal muscle-specific modulates pattern of expression in myogenesis in response to endurance training in human

Alves, Cleber Renê 14 May 2014 (has links)
O treinamento físico aeróbio (TFA) foi estabelecido como uma conduta importante capaz de alterar a musculatura esquelética humana. Os microRNAs (miRs) surgiram como importantes reguladores de processos biológicos, modulando a expressão de genes pós-transcricionalmente. Os myomiRs são miRs específico do músculo esquelético, em especial o miR-206, que é necessário para uma eficiente regeneração das fibras musculares esqueléticas. No entanto, a expressão do miR-206 em resposta ao TFA, não é completamente comprendida. O objetivo do presente estudo foi determinar os padrões de expressão dos myomiRs na musculatura esquelética humana. Doze voluntários saudáveis foram biopsiados pré e pós-treinamento físico. As expressões gênicas e proteicas envolvidas na miogênese foram observadas, incluindo; PAX-7, MYF5, MYOD, MRF4, MYOG, CD31 e FSTL. Além disso, a freqüência cardíaca (FC), pressão arterial média (PAM), consumo máximo de oxigênio (VO2max), fluxo sanguineo no antebraço (FSA) e condutância vascular no antebraço (CVA), foram avaliados. Ademais, os myomiRs foram analisados por PCR em tempo real. O treinamento físico aeróbio foi realizado durante 16 semanas. Todas as variáveis foram reavaliadas após o treinamento. Os indivíduos apresentaram um aumento nas expressões dos myomiRs, em especial do miRs-206 de 93%. Estas alterações foram acompanhadas por aumento nas expressões dos genes; PAX-7, MYOD, MYF5, MFR4, MYOG e FSTL, respectivamente. No entanto, quando analisamos as expressões proteicas, houve redução na FSTL e PAX-7, de 24%, 29%, respectivamente. Além disso, em MYOD, CD31, MYOG e MHC houve aumentos de 21%, 41%, 79% e 94%, respectivamente. Ademais, houve uma diminuição na frequência cardíaca de reposuso de 12,5% e aumentos no VO2pico, FSA e CVA de 14,1%, 68%, 63%, respectivamente. Estes resultados sugerem que em indivíduos saudáveis o miRs-206 é altamente expresso após o treinamento físico aeróbio, dessa forma, modulando localmente processos miogênicos regenerativos em homens saudáveis / Endurance training (ET) has been established as an important phenotype capable of altering the human skeletal muscle. MicroRNAs (miRs) have emerged as important regulators of numerous biological processes by modulating gene expression at the post-transcriptional level. The myomiRs are particulars miRs of muscles, in special skeletal muscle-specific miR-206 that is required for efficient regeneration muscle fiber. However, the expression of myomiRs and in special miR-206 in response to ET in human skeletal muscle is not completely understood. Twelve healthy volunteers were biopsied pre and post period endurance training. Most of the biological processes involved in the transcriptional regulation were observed, including PAX-7, MYF5, MYOD, MRF4, MYOG, CD31 and FSTL, analyzed by real time PCR. Moreover, heart rate (HR), mean blood pressure (MBP), maximal exercise capacity (VO2peak) forearm blood flow (FBF) and forearm vascular conductance (FVC) were evaluated. The myomiRs levels analyzed by real-time PCR. Endurance training was performed for 16 weeks. All variables were re-assessed following completion of the training period. After endurance training, the individuals showed an increase in myomiRs, in special of 93% in human skeletal muscle in miRNA-206 levels. These alterations were accompanied by increase in PAX-7, MYOD, MYF5, MFR4, MYOG and FSTL gene expression, respectively. However, when analyzed by western blot comparing pre and post period there were reduction in FSTL of 24% and PAX-7 of 29% in protein levels, but in MYOD, CD31, MYOG and MHC there were increase of 21%, 41%, 79% and 94% in protein levels, respectively. In addition, there was a decrease in hear rate of 12.5% and increases in VO2peak of 14.1%, FBF of 68% and FVC of 63%.These results suggest that in healthy individuals the miR-206 is highly expressed after endurance training, thus modulating locally important parts in myogenic processes in humans
97

Expressão e seleção de microRNAs no músculo esquelético de homens saudáveis submetidos ao treinamento físico aeróbio\" / MicroRNA-206 skeletal muscle-specific modulates pattern of expression in myogenesis in response to endurance training in human

Cleber Renê Alves 14 May 2014 (has links)
O treinamento físico aeróbio (TFA) foi estabelecido como uma conduta importante capaz de alterar a musculatura esquelética humana. Os microRNAs (miRs) surgiram como importantes reguladores de processos biológicos, modulando a expressão de genes pós-transcricionalmente. Os myomiRs são miRs específico do músculo esquelético, em especial o miR-206, que é necessário para uma eficiente regeneração das fibras musculares esqueléticas. No entanto, a expressão do miR-206 em resposta ao TFA, não é completamente comprendida. O objetivo do presente estudo foi determinar os padrões de expressão dos myomiRs na musculatura esquelética humana. Doze voluntários saudáveis foram biopsiados pré e pós-treinamento físico. As expressões gênicas e proteicas envolvidas na miogênese foram observadas, incluindo; PAX-7, MYF5, MYOD, MRF4, MYOG, CD31 e FSTL. Além disso, a freqüência cardíaca (FC), pressão arterial média (PAM), consumo máximo de oxigênio (VO2max), fluxo sanguineo no antebraço (FSA) e condutância vascular no antebraço (CVA), foram avaliados. Ademais, os myomiRs foram analisados por PCR em tempo real. O treinamento físico aeróbio foi realizado durante 16 semanas. Todas as variáveis foram reavaliadas após o treinamento. Os indivíduos apresentaram um aumento nas expressões dos myomiRs, em especial do miRs-206 de 93%. Estas alterações foram acompanhadas por aumento nas expressões dos genes; PAX-7, MYOD, MYF5, MFR4, MYOG e FSTL, respectivamente. No entanto, quando analisamos as expressões proteicas, houve redução na FSTL e PAX-7, de 24%, 29%, respectivamente. Além disso, em MYOD, CD31, MYOG e MHC houve aumentos de 21%, 41%, 79% e 94%, respectivamente. Ademais, houve uma diminuição na frequência cardíaca de reposuso de 12,5% e aumentos no VO2pico, FSA e CVA de 14,1%, 68%, 63%, respectivamente. Estes resultados sugerem que em indivíduos saudáveis o miRs-206 é altamente expresso após o treinamento físico aeróbio, dessa forma, modulando localmente processos miogênicos regenerativos em homens saudáveis / Endurance training (ET) has been established as an important phenotype capable of altering the human skeletal muscle. MicroRNAs (miRs) have emerged as important regulators of numerous biological processes by modulating gene expression at the post-transcriptional level. The myomiRs are particulars miRs of muscles, in special skeletal muscle-specific miR-206 that is required for efficient regeneration muscle fiber. However, the expression of myomiRs and in special miR-206 in response to ET in human skeletal muscle is not completely understood. Twelve healthy volunteers were biopsied pre and post period endurance training. Most of the biological processes involved in the transcriptional regulation were observed, including PAX-7, MYF5, MYOD, MRF4, MYOG, CD31 and FSTL, analyzed by real time PCR. Moreover, heart rate (HR), mean blood pressure (MBP), maximal exercise capacity (VO2peak) forearm blood flow (FBF) and forearm vascular conductance (FVC) were evaluated. The myomiRs levels analyzed by real-time PCR. Endurance training was performed for 16 weeks. All variables were re-assessed following completion of the training period. After endurance training, the individuals showed an increase in myomiRs, in special of 93% in human skeletal muscle in miRNA-206 levels. These alterations were accompanied by increase in PAX-7, MYOD, MYF5, MFR4, MYOG and FSTL gene expression, respectively. However, when analyzed by western blot comparing pre and post period there were reduction in FSTL of 24% and PAX-7 of 29% in protein levels, but in MYOD, CD31, MYOG and MHC there were increase of 21%, 41%, 79% and 94% in protein levels, respectively. In addition, there was a decrease in hear rate of 12.5% and increases in VO2peak of 14.1%, FBF of 68% and FVC of 63%.These results suggest that in healthy individuals the miR-206 is highly expressed after endurance training, thus modulating locally important parts in myogenic processes in humans
98

Exercise-induced muscle soreness : a qualitative and quantitative study of human muscle morphology and function

Fridén, Jan January 1983 (has links)
Exercise-induced muscle soreness is characterized by stiffness, tenderness and pain during active movements and weakness of the affected musculature the days after unusually or particularly heavy work. The most pronounced subjective symptoms do not arise immediately but rather between a couple of hours to some days after the exercise (a delayed-onset of muscle soreness), the intensity of pain is greatest about 48 hours after the work. A particular association exists between muscle soreness and eccentric contractions. Despite the fact that muscle soreness is a well known phenomenon in the sphere of sports as well as working life, the pathophysiological mechanisms underlying this are still not understood. In the present study a detailed analysis of human muscle fibre population structure after high tension work (eccentric exercise) that gave rise to muscle soreness, was carried out. The objective was to elucidate how fibres of different types are influenced by repeated muscle contractions reaching extreme tension levels using qualitative and quantitative light and electron microscopic techniques. It was hoped that such morphological analysis would provide a basis for discussion of possible causes for muscle soreness. The muscle function after the work was measured by isokinetic methods. To improve the basis for the ultrastructural analysis the fibre populations in untrained and en­durance trained human m. vastus lateralis of age-matched individuals were classified into different fibre type groups according to their ultrastructure. The selective glycogen depletion from Type 1 fibres seen after long term submaximal work, visualized electron microscopically with PA-TSC-SP staining, substantiated the usefulness of the appearance of the M-band to differentiate between fibre types. Stereological data showed that neither volume density of mitochondria nor of lipid droplets provide sufficient criteria to differentiate between fibre types. After an eccentric exercise regimen sore muscles (m. soleus or m. vastus lateralis) showed disturb­ances of the cross striated band pattern. Fibres with disorganized myofibrillar material made up 1/3, 1/2 and 1/10 of the analysed material, 1 hour, 3 and 6 days after exercise, respectively. The myofibril­lar lesions were preferably localized in the Z-band. This showed streaming, broadening and sometimes total disruption. The Type 2 fibres were most affected. The reduction of strength was greatest with the most rapid contractions. Strength remained de­creased the period when the structural damage was most pronounced. Eight weeks of eccentric muscle training reduced all the above negative effects. The results indicate that the Z-disc constitute the weak link in the myofibrillar contractile chain at high muscle tensions. It is suggested that the myofibrillar lesions are a direct result of mechanical tearing. Rupture of myofibrils is thought to result in formation of protein components and a con- sequental release of protein bound ions that via osmosis result in oedema and soreness. Training, using eccentric contractions over a long period of time leads to adaptations at the fibre level by a reorgani­zation of the contractile apparatus as well as an optimization of nervous coordination. / <p>S. 1-40: sammanfattning, s. 41-79: 5 uppsatser</p> / digitalisering@umu
99

Análise da estratégia de corrida e suas relações com variáveis de desempenho de atletas / Relationship of the pacing strategy with performance variables

Pacheco, Marcelo da Silva 12 April 2012 (has links)
O objetivo do estudo foi examinar a influência de variáveis fisiológicas, perceptuais e mecânicas nas diferentes estratégias de corrida e no desempenho de atletas. Doze corredores especialistas em 5.000m realizaram: 1) um teste escalonado máximo para identificação do consumo máximo de oxigênio (VO2máx), velocidade de corrida associada ao VO2máx (vVO2máx), pico de velocidade em esteira (PVE) e velocidade de corrida associada ao limiar anaeróbio (vLAn); 2) uma prova de corrida de 5.000m avaliada a cada trecho (n = 5) de 1.000m em pista de atletismo para registro da frequência cardíaca (FC), percepção subjetiva de esforço (PSE) e velocidade de corrida. Os sujeitos foram divididos em dois grupos: saída lenta (SL) e saída rápida (SR) de acordo com a estratégia adotada, que por sua vez foi baseada na relação da velocidade de corrida no trecho inicial (Vel20%) com a velocidade média do teste de 5.000m. Os dados foram comparados entre os grupos de estratégia e posteriormente entre os trechos da prova esportiva para cada variável analisada. A velocidade de corrida no trecho inicial (SL = 16,9km.h-1 e SR = 19,1km.h-1) e no trecho final (SL = 19,1km.h-1 e SR = 16,7km.h-1) foi significantemente diferente (p < 0,05), o mesmo não ocorreu com a PSE. Já a FC nos três últimos trechos (SL = 185; 188 e 195 bpm e SR = 191; 193 e 200 bpm) apresentou diferença significante (p < 0,05) entre os grupos avaliados. Adicionalmente, foram encontradas associações entre PVE e Vel20% (rs = 0,57; p < 0,05), vVO2máx e Vel20% (rs = 0,55; p < 0,05), e entre vLAn e Vel20% (rs = 0,54; p < 0,05). Quando os parâmetros de desempenho (FC, PSE e velocidade de corrida) foram comparados dentro de cada grupo, apresentaram diferença significante (p < 0,05) entre todos os trechos analisados do teste. Dessa forma, concluímos haver influência da estratégia adotada no início da prova sobre a regulação da velocidade e sobre o desempenho na corrida de 5.000m, sobretudo, quando relacionada a parâmetros fisiológicos, perceptuais e mecânicos / The objective of this study was to examine the influence of physiological, perceptual and mechanical parameters in different pacing strategies and performance of athletes. Twelve runners performed: 1) a test scaled maximal to identify the maximum oxygen uptake (VO2max), running velocity associated with VO2max (vVO2max), peak treadmill velocity (PTV) and running velocity associated with the anaerobic threshold (vAnT); 2) a time trial evaluated in each 1,000m in the track to record heart rate (HR), rating of perceived exertion (RPE) and running speed. The subjects were divided into two groups: slow start (SS) and fast start (FS) in accordance with the strategy used, which in turn was based on the ratio of the velocity of the initial split (Vel20%) with the speed average of the time trial. Data were compared between groups of the pacing strategy for each variable analyzed. The velocity at the initial split (SS = 16.9 km.h-1 and FS = 19.1 km.h-1) and in the final split (SS = 19.1 km.h-1 and FS = 16.7 km.h-1) was different significantly (p < 0.05), but the same did not occur with the RPE. The HR in the last three splits (SS = 185, 188 and 195 beats.min-1 and FS = 191, 193 and 200 beats.min-1) showed significant difference (p < 0.05) between groups. In addition, associations were found between PTV and Vel20% (rs = 0.57, p < 0.05), vVO2max and Vel20% (rs = 0.55, p < 0.05) and between vAnT and Vel20% (rs = 0.54, p < 0.05). When the performance parameters (HR, RPE and running speed) were compared within each group, there were significant differences (p < 0.05) among all splits analyzed. Thus, we conclude there is influence of the strategy adopted at the start of the time trial and the speed regulation on the performance in the 5,000m running, especially when related to physiological, perceptual and mechanical parameters
100

Étude des mécanismes psychophysiologiques impliqués dans la réalisation d’une performance cycliste de haut-niveau / Analysis of the psychophysiological mechanisms of elite cycling performance

Ouvrard, Théo 06 December 2018 (has links)
Les travaux conduits dans le cadre de cette thèse avaient pour objectif d’étudier les mécanismes psychophysiologiques impliqués dans la mobilisation et la gestion des ressources nécessaires à la réalisation d’une performance de haut niveau en cyclisme sur route. Les mécanismes centraux et les paramètres psychologiques susceptibles d’influencer la commande motrice ont ainsi été analysés dans le contexte de compétitions cyclistes de haut-niveau.L’ensemble des résultats obtenus mettent en évidence que les mécanismes de régulation de l’intensité d’exercice, évalués à l’aide de la nouvelle méthode « Exposure Variation Analysis » (EVA) développée dans le cadre de cette thèse, seraient des paramètres déterminants pour la performance cycliste en contre-la-montre (CLM). En compétition officielle, la capacité du cycliste à exploiter au mieux ses qualités physiques et donc à développer la plus haute puissance moyenne possible était directement reliée à sa capacité à maintenir un niveau d’intensité d’exercice constant sur l’ensemble du CLM. De plus, cette justesse de régulation de l’intensité de l’effort serait également liée aux paramètres psychologiques de plaisir ressenti et de focus attentionnel : plus l’athlète ressentait un plaisir important et était capable de focaliser ses pensées sur des éléments extérieurs pertinents pour la performance et plus il était capable de maintenir un niveau de puissance constant sur l’ensemble de l’effort. Ainsi, la performance cycliste serait dépendante de l’interaction complexe entre les paramètres psychologiques, les mécanismes de régulation de l’effort et les qualités physiques des athlètes.Cependant, les résultats des études menées dans le cadre de cette thèse mettent également en évidence que les mécanismes de régulation de l’intensité d’exercice et les paramètres psychologiques associés varient selon le contexte environnemental et les caractéristiques de l’effort réalisé. Par exemple, la présence d’un équipier en montée permettrait au cycliste de ressentir un plaisir plus élevé pendant l’effort et de puiser davantage dans ses réserves afin de réaliser un sprint final plus important dans les derniers mètres avant l’arrivée. A l’inverse, les cyclistes de niveau élite possèderaient des qualités de gestion de l’effort remarquables leur permettant de réguler l’effort de manière identique lors de plusieurs montées répétées que lors d’un effort unique. L’étude de la performance cycliste doit donc prendre en compte le contexte environnemental ainsi que les caractéristiques des athlètes et de l’effort réalisé afin de réellement permettre une compréhension complète de la performance cycliste de haut-niveau.De plus, ces résultats mettent également en évidence que les mécanismes de régulation de l’effort peuvent évoluer entre les différentes compétitions, et pourraient ainsi expliquer les variations journalières de performance pour un même niveau de qualité physique. Les travaux menés dans le cadre de cette thèse ont ainsi tenté d’optimiser la méthode EVA afin de permettre le suivi de la justesse des mécanismes de régulation de l’effort du cycliste lors de plusieurs CLM. Cette méthode pourrait se révéler très intéressante pour les entraîneurs et les athlètes sur le terrain afin de tenter d’optimiser leurs mécanismes de régulation de l’effort avec l’entraînement dans le but d’exploiter au mieux leurs qualités physiques. Des techniques psychologiques pourraient notamment être utilisées afin d’augmenter le plaisir ressenti des athlètes ou d’optimiser leur gestion des pensées pendant l’effort, leur permettant ainsi de mieux réguler l’intensité d’exercice et d’améliorer leurs performances en CLM. / The studies conducted during this PhD thesis aimed to analyse the psychophysiological mechanisms of effort regulation during elite road cycling performance. Central mechanisms and psychological parameters influencing motor units recruitment were studied in different contexts of elite road cycling competitions.All the results show that exercise intensity regulation, quantified using the “Exposure Variation Analysis” method developed during this PhD, is a key parameter of cycling individual time-trial (ITT) performance. During official competitive ITT, the cyclists’ abilities to have a maximal use of their physical capacities in order to develop the highest mean power output possible was strongly related to their abilities to maintain a constant level of exercise intensity during the entire ITT. These exercise intensity regulation mechanisms were also strongly related to pleasure and attentional focus psychological parameters: the more the athletes felt a high level of pleasure and were able to focus mainly on external thoughts salient to the performance, the more they were able to maintain a constant power output over the entire ITT. Cycling performance seems related to the complex interaction between psychological parameters, exercise intensity regulation mechanisms and physical capacities.However, the studies conducted also revealed that exercise intensity regulation mechanisms and psychological parameters varied depending on the environmental context and the characteristics of the effort. For example, a leading teammate in uphill cycling allowed the athlete to increase their pleasure and to dig deeper into their physiological reserves in order to perform a greater end-spurt. Conversely, elite cyclists exhibited outstanding exercise intensity regulation capacities which allowed them to regulate their effort during repeated uphill ITT in the same way that during single ITT. Consequently, the study of elite cycling performance must consider both environmental context and characteristics of the athletes concerned to allow a complete understanding of the mechanisms underlying performance.Furthermore, these results also underline that exercise intensity regulation mechanisms can vary between races, and consequently can explain the day-to-day variability in cycling performance despite similar physical capacities. Thus, the EVA method was optimised in order to monitor exercise intensity regulation mechanisms during several ITT performed by the same athletes. This method can be interesting for coaches and athletes on the field to try to improve their exercise intensity regulation with training. Specific psychological interventions can be added to the training programs in order to help the athlete to increase their pleasure or to improve their attentional focus, allowing them to improve their exercise intensity regulation and to have a greater use of their physical capacities during ITT.

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