The regulation of exercise performance by a complex anticipatory system

 

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dc.contributor.advisor Noakes, Tim en_ZA
dc.contributor.author Tucker, Ross en_ZA
dc.date.accessioned 2014-07-28T18:15:36Z
dc.date.available 2014-07-28T18:15:36Z
dc.date.issued 2006 en_ZA
dc.identifier.citation Tucker, R. 2006. The regulation of exercise performance by a complex anticipatory system. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/3207
dc.description Includes bibliographical references (p. 228-241).
dc.description.abstract The present thesis examined the hypothesis that self-paced exercise performance and pacing strategies are regulated by a complex intelligent system in advance of a failure to maintain homeostasis in one or more physiological systems. In the first study, ten trained cyclists performed 20 km cycling time-trials in hot (35°C) and cool (15°C) conditions. The power output was reduced in the heat despite core temperatures that were sub-maximal and not different from those measured in the cool condition. Significantly, the reduction in power output was associated with a lower IEMG activity in the active muscle, suggesting that the brain recruited less muscle even at sub-maximal body temperatures. Thus, self-paced exercise in the heat was regulated in advance of thermoregulatory failure. This model was then applied to conditions where the oxygen content of the air was elevated (yperoxia). Eleven subjects performed 20km time-trails, and it was found that a higher power output was maintained throughput hyperoxic (F₁O₂0.21), and that the IEMG activity was elevated in hyperoxia. The subjective rating of perceived exertion (RPE), measured using the Borg scale, was similar in both this and the first study, despite differences in power output. It was suggested that the RPE may play a mediatory role. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Human Biology en_ZA
dc.title The regulation of exercise performance by a complex anticipatory system en_ZA
dc.type Doctoral Thesis
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Health Sciences en_ZA
dc.publisher.department Department of Human Biology en_ZA
dc.type.qualificationlevel Doctoral
dc.type.qualificationname PhD en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Tucker, R. (2006). <i>The regulation of exercise performance by a complex anticipatory system</i>. (Thesis). University of Cape Town ,Faculty of Health Sciences ,Department of Human Biology. Retrieved from http://hdl.handle.net/11427/3207 en_ZA
dc.identifier.chicagocitation Tucker, Ross. <i>"The regulation of exercise performance by a complex anticipatory system."</i> Thesis., University of Cape Town ,Faculty of Health Sciences ,Department of Human Biology, 2006. http://hdl.handle.net/11427/3207 en_ZA
dc.identifier.vancouvercitation Tucker R. The regulation of exercise performance by a complex anticipatory system. [Thesis]. University of Cape Town ,Faculty of Health Sciences ,Department of Human Biology, 2006 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/3207 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Tucker, Ross AB - The present thesis examined the hypothesis that self-paced exercise performance and pacing strategies are regulated by a complex intelligent system in advance of a failure to maintain homeostasis in one or more physiological systems. In the first study, ten trained cyclists performed 20 km cycling time-trials in hot (35°C) and cool (15°C) conditions. The power output was reduced in the heat despite core temperatures that were sub-maximal and not different from those measured in the cool condition. Significantly, the reduction in power output was associated with a lower IEMG activity in the active muscle, suggesting that the brain recruited less muscle even at sub-maximal body temperatures. Thus, self-paced exercise in the heat was regulated in advance of thermoregulatory failure. This model was then applied to conditions where the oxygen content of the air was elevated (yperoxia). Eleven subjects performed 20km time-trails, and it was found that a higher power output was maintained throughput hyperoxic (F₁O₂0.21), and that the IEMG activity was elevated in hyperoxia. The subjective rating of perceived exertion (RPE), measured using the Borg scale, was similar in both this and the first study, despite differences in power output. It was suggested that the RPE may play a mediatory role. DA - 2006 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2006 T1 - The regulation of exercise performance by a complex anticipatory system TI - The regulation of exercise performance by a complex anticipatory system UR - http://hdl.handle.net/11427/3207 ER - en_ZA


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