Thesis (M.S.)--University of Wisconsin--Madison, 1985. / Typescript (photocopy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 168-174).

This study investigated the influence of computer-generated reminders on the rate in which distance learners submitted assignments and completed courses. The computer-generated reminders, sent via email, served as a time management support strategy. Participants were randomly divided into two groups: control and treatment. Both groups received a list of target due dates for course assignments. The control group did not receive reminders. The treatment group received reminders when they failed to submit an assignment by a target due date. The results indicated no significant difference between the control and treatment groups in terms of assignment submission rates and course completion rates. However, results of this study did reveal that the number of assignments in a distance course influences the timeliness of assignment completion and the likelihood of course completion. / Ph. D.

Pacing, a common form of stereotypy in captive animals, poses challenges for animal welfare and conservation initiatives. The current study used a comprehensive measurement system to investigate the impact of introducing a food-related activity on the daily patterns of multiple behaviors, including stereotypic pacing, in two zoo-housed cougars. The results showed that, while the intervention did not mitigate pacing overall, it did cause a shift in the cougars' routines. This demonstrated the significant influence of keeper behavior on the animals. Furthermore, the differing effects on each cougar's behaviors underscored the necessity for individualized interventions tailored to the specific needs of animals.

É reconhecido que as técnicas de enriquecimento ambiental são importantes ferramentas para a melhoria do bem-estar de animais cativos. No entanto, questões em torno da efetividade e temporariedade dos efeitos das práticas requerem investigação e aprimoramento. O presente estudo foi realizado com o objetivo de analisar a influência de diferentes tipos de enriquecimentos, assim como o tamanho do recinto no comportamento de felinos em cativeiro. O estudo foi dividido em três partes, na primeira, buscou-se analisar se um enriquecimento classificado como intrínseco (catnip) e outro extrínseco (quebra-cabeça alimentar) apresentaram efeitos na expressão de comportamentos direcionados ao enriquecimento e de pacing em jaguatiricas (Leopardus pardalis) quando aplicados por meio de frequências de exposição consecutiva (sete dias) ou intermitente (a cada dois dias). A segunda parte do estudo concentrou-se em investigar se jaguatiricas alojadas em recintos maiores apresentaram diferenciada expressão de pacing em comparação àquelas residentes em recintos menores, sob duas condições: sem aplicação (linha de base) e com aplicação de enriquecimento (catnip e quebra-cabeça alimentar). Por fim, a terceira parte investigou se três enriquecimentos intrínsecos (bola de feno sem odor, com catnip e canela) influenciaram de forma distinta os comportamentos de guepardos (Acinonyx jubatus) e tigres de Sumatra (Panthera tigris sumatrae) em termos da expressão dos comportamentos de pacing, locomoção, inatividade, exploração e comportamento direcionado ao enriquecimento. Em síntese, os resultados indicaram que as dimensões dos recintos influenciaram no comportamento de pacing em jaguatiricas, apresentando maior ocorrência de pacing nos indivíduos alojados em cativeiros pequenos. O enriquecimento extrínseco utilizado (quebra-cabeça alimentar) demonstrou efeito de longa duração em comparação ao intrínseco (catnip), em termos de tempo de interação, assim como, indicaram maior influência na redução da expressão da estereotipia. Por outro lado, os enriquecimentos intrínsecos aplicados no estudo demonstraram um efeito de curto prazo para os comportamentos direcionados ao enriquecimento, contudo, a essência de canela reduziu significativamente os níveis de pacing em guepardos e tigres de Sumatra. Em termos de frequencia de exposição, os felinos não demonstraram efeitos de habituação aos estímulos apresentados entre sessões (ao longo do período experimental), para ambas as condições de apresentação (consecutiva e intermitente). As descobertas do presente estudo contribuíram com a resolução de questões relacionadas ao aprimoramento da ciência do enriquecimento. Dentre estas destacam-se: 1) tipos diferentes de enriquecimentos demonstraram causar efeitos distintos no comportamento dos animais, sugerindo que as práticas devem ser em aplicadas para atingir objetivos específicos de acordo com os efeitos provocados (longo-prazo, curto-prazo e/ou redução de estereotipias); 2) características ambientais, como o tamanho do recinto, podem influenciar o comportamento de animais que ocupam grandes extensões em relação a comportamentos anormais; e por fim 3) a complexidade proporcionada pelo enriquecimento pode minimizar esses efeitos maleficentes. Os resultados apresentados nesta pesquisa destacam a importância de investigações focadas no impacto das características do recinto, eficácia do enriquecimento nas interferências comportamentais e no design metodológico, a fim de atender às necessidades comportamentais dos animais em cativeiro. / Environmental enrichment techniques have been shown to be a powerful tool to improve the welfare of captive animals. However, many issues regarding effectiveness and temporality of the effects on behavioural interference require investigations and improvement. This study was conducted to analyse how environmental enrichments classified as intrinsic and extrinsic, as well the enclosure sizes influence the behaviour of wild cats kept in captivity. In the first part of this study the effects of an intrinsic (catnip scent) and an extrinsic (puzzle-feeder) environmental enrichment on the duration of enrichment-directed and pacing behaviours in captive ocelots (Leopardus pardalis), considering two application schedules, consecutive (seven days) or intermittent (every two days) was addressed. In the second part it was investigated if the enclosure size affects the duration of pacing behaviour by ocelots kept under enriched (catnip and puzzle-feeder) and non-enriched (baseline) environmental conditions; and in the third part it was tested if three intrinsic enrichments (hay balls without scent, with catnip and with cinnamon) had distinct effects on cheetahs (Acinonyx jubatus) and Sumatran tigers (Panthera tigris sumatrae) behaviour regarding pacing, locomotion, inactive, exploratory and enrichment-directed behaviours. In summary, results demonstrated that the enclosure size have a high impact in the duration of pacing behaviour expressed by the ocelots. The extrinsic enrichment (puzzle-feeder) presented a long-term effect on ocelots behaviour, resulting in a reduction of pacing time. On the other hand, the intrinsic enrichments promoted a short-lived effect in cheetahs and Sumatran tigers, and cinnamon demonstrated a better influence on the reduction of pacing behaviour than catnip. In terms of frequency of exposure the wild cats did not get habituated to the practices between sessions (over experimental days), for either consecutive or intermittent application schedules. The findings presented here elucidated issues related to enrichment science improvement. Among these stand out: 1) different types of practices cause distinct effects on animals behaviours, and should be applied according to the aim proposed to achieve (long-term, short-term or stereotypy reduction); 2) enclosure sizes can influence the behaviour of wide-ranging animals kept in captivity; and 3) the environmental complexity, provided by the environmental enrichment practices, reduces the negative effect of small sized enclosures in ocelots. The presented outcomes highlight the importance of investigations focused on the impact of enclosure features and the efficacy of environmental enrichment and methodological design for its application for the welfare of captive animals.

The effect of CRT on incidence of AF development in patients with severe HF was explored by comparing 36 patients with conventional indication for the CRT to 36 HF patients without CRT, matched for age, sex and LV systolic function (Publication 5). After a follow up of 3 years, the annual incidence of AF in the CRT group was 2.8%, which was significantly lower than the control group (10.2%). Moreover, the echocardiographic benefit by CRT was compared between these 36 patients with SR and 15 patients with persistent AF. The results showed that the echocardiographic response was similar between the two groups. These findings suggested that CRT may have the potential to reduce AF burden in patients with severe HF and that patients with persistent AF may also benefit from CRT. / The objective of the study (Publication 1) was to assess the feasibility of using non-contact LV mapping to delineate the LV endocardial activation pattern in 7 HF patients in NYHA class III, with low LVEF and wide QRS complex (>120ms). Non-contact mapping was safely performed and there were two endocardial conduction patterns identified, namely homogenous (Type I) and conduction block (Type II). The second part of the study (Publication 2) was to determine the implication of these two distinct activation patterns to echocardiographic and clinical response to CRT. 23 patients in NYHA class III, with LVEF <35% and QRS duration >120ms were recruited in this study. 15 patients had Type II pattern and 8 Type I. The QRS duration between the two types of conduction patterns were comparable. Patients with Type II pattern had a more favourable echocardiographic and clinical response to CRT than those with Type I. It was concluded that, despite the similar QRS duration between the two types of LV endocardial activation patterns, patients with Type II pattern had a more favourable response to CRT. / The significance of baseline renal function in CRT was assessed in 85 consecutive patients with conventional indication for the CRT (Publication 7). There was no significant relationship between baseline renal function and significant LV reverse remodeling after CRT, suggesting baseline renal insufficiency probably would not affect the response to CRT. (Abstract shortened by UMI.) / This study (Publication 3) was to determine the effect of CRT in patients with narrow QRS complex and evidence of mechanical dyssynchrony as determined by TDI. 51 patients in NYHA class III or IV, with LV ejection fraction <35%, and QRS duration <120ms were recruited for the CRT. The effect of the device therapy on LV systolic function in this cohort was compared to 51 patients who fulfilled the current criteria with wide QRS complex. CRT significantly improved the LV systolic function, NYHA class and exercise capacity in those with narrow complex to a similar extent in those with wide complex. With co-existing mechanical dyssynchrony determined by TDI, patients in both narrow and wide QRS complex groups showed more favourable response to CRT than those without significant mechanical dyssynchrony. This confirmed that QRS was a poor marker of mechanical dyssynchrony and the current selection criteria are probably not adequate to include more potential responders to the therapy. / This study (Publication 4) was to determine the role of optimal medical therapy in CRT recipients before implantation. The echocardiographic and clinical effect of CRT in 30 patients without the optimal combination of ACEi or ARB and beta-blockers was compared to 30 patients matched for age, sex, NYHA class and HF etiology. Patients with optimal medical therapy had significantly better echocardiographic and clinical response to CRT. The results confirmed that optimal medical therapy is necessary to achieve maximal response by CRT. / This study (Publication 6) was to determine if patients with moderate LV systolic function and wide QRS complex would benefit from the CRT. Significant improvement in LV systolic function was observed in 15 patients with LVEF between 35 and 45%, NYHA class III and QRS duration >120ms after CRT, suggesting that presence of LV systolic dysfunction and cardiac dyssynchrony may be the major determining factors for favourable CRT response. Therefore, patients with less advanced HF may also benefit from the CRT. / "May 2007." / Adviser: Yu Cheuk Man. / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4657. / Thesis (M.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 133-151). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / School code: 1307.

A presente dissertação procurou determinar as fases do pacing strategy em \"U\" e analisar o desenvolvimento da fadiga neuromuscular e o perfil metabolômico em um teste contrarrelógio de 4 km no ciclismo (4 km CT). No estudo 1, foi proposto dois modelos (visual e matemático) para determinar as três fases do pacing strategy em \"U\" durante um 4 km CT. Foram recrutados 15 ciclistas para realizar dois testes 4 km CT em dias separados. Para o modelo visual, quatro avaliadores experientes analisaram o pacing strategy duas vezes, sete dias de diferença. O modelo matemático foi composto pela média da potência durante a fase 2 (1 até 3 km) mais dois desvios padrões, identificando o ponto de mudança (PM) da fase 2 entre fase 1 (PM1) e 3 (PM2). O PM1 ocorreu em 419 ± 186 e 415 ± 178 m e PM2 ocorreu em 3646 ± 228 e 3809 ± 213 m para o modelo visual e matemático. Não houve diferença entre os modelos para ambos PM (p > 0,05). A reprodutibilidade intra avaliadores no modelo visual para PM1 e PM2 foi ICC >= 0,87 e >= 0,96 (p < 0,05), e entre avaliadores foi ICC >= 0,89 (p < 0,05). Gráficos de Bland-Altman mostraram boa concordância entre modelos, maioria da diferença ficou abaixo de 5%. O estudo 1 sugere que ambos modelos são reprodutíveis e produzem valores similares para determinar as fases do pacing strategy em \"U\". No estudo 2, 11 ciclistas visitaram o laboratório em seis ocasiões, sendo familiarizados três vezes com 4 km CT e técnica de estimulação elétrica no nervo femoral. Nas últimas três visitas, o mesmo pacing strategy da familiarização foi reproduzido, porém foram interrompidos ao final da fase 1 (F1FINAL), fase 2 (F2FINAL) e fase 3 (F3FINAL), randomizado. Antes e logo após o exercício, os ciclistas realizaram a técnica de estimulação elétrica e amostras sanguíneas foram coletadas para determinar o perfil metabolômico. A F1 teve duração de 68 ± 14 s (83,1% acima do ponto de compensação respiratória (PCR), em relação ao tempo total da F1), a F2 durou 287 ± 17 s (24,9% acima do PCR, tempo total da F2) e F3 durou 33 ± 7 s (74,5% acima do PCR, tempo total da F3). Houve apenas efeito principal de tempo para maioria das variáveis neuromusculares (p < 0,05) e não houve efeito principal de condição (p > 0,05). Apenas 5 metabólitos tiveram diferença estatística. Valores menores de 2-oxoisocarporate e dimatilamina para F1FINAL comparado com F2FINAL (p < 0,05). Valores menores de succinato para F1FINAL comparado com F3FINAL (p < 0,05). Asparagina e lactato apresentaram valores menores para F1FINAL em comparação à F2FINAL e F3FINAL (p < 0,05). Esses achados sugerem que, ao longo de um teste 4 km CT, o nível de fadiga neuromuscular é estabelecido logo no início e mantido até o final da tarefa. Não obstante, o perfil metabolômico parece estar associado com metabólitos da via oxidativa e outros marcadores relevantes para o SNC controlar a intensidade do exercício / The present dissertation aimed to determine the distinct phases of \"U\" pacing strategy and the development of neuromuscular fatigue and metabolomic profile during a 4 km cycling time trial (4 km TT). The study 1 developed two models (visual and mathematical) to determine the three different phases of \"U\" pacing strategy during a 4 km TT. Fifteen cyclists were recruited to perform two 4 km TT at different days. For the visual model, four experienced evaluators analysed the pacing twice, seven days apart. The mathematical model was composed by the mean of power output during phase 2 (1 until 3 km) plus two standard deviation, which was the criteria to distinguish the change point (CP) of phase 2 among phase 1 (CP1) and 3 (CP2). CP1 occurred at 419 ± 186 and 415 ± 178 m and CP2 occurred at 3646 ± 228 and 3809 ± 213 m for the visual and mathematical models. There was no difference between models for both CP (p > 0.05). The intra-evaluator reliability of visual model for CP1 and CP2 were ICC >= 0.87 and >= 0.96 (p < 0.05), and the betweenevaluator was ICC >= 0.89 (p < 0.05). The Bland-Altman plots showed great agreement between models, with most values lower than 5% of difference. In conclusion, both models were reliable and produced similar values to distinguish the phases during \"U\" pacing strategy. At study 2, 11 cyclists visited the lab on six occasions, where they were familiarized three times with the 4 km TT and the femoral nerve stimulation technique. On the last three visits, the same pacing strategy from the familiarization was performed, but the cyclists were interrupted at the end of phase 1 (P1END), end of phase 2 (P2END) and end of phase 3 (P3END), randomized. Before and immediately after the exercise, the cyclists performed the stimulation technique and blood samples were collected to determine the metabolimic profile. The P1 had duration of 68 ± 14 s (83.1% above the respiratory compensation point (RCP), in relation with total time of P1), P2 lasted 287 ± 17 s (24.9% above RCP, from total time at P2) and P3 lasted 33 ± 7 s (74.5% above RCP, from total time at P3). Most of neuromuscular variables showed main effect of time (p < 0.05) but no main effect of condition (p > 0.05). Only five metabolites were statistically different among conditions. 2- oxoisocarporate and dimethylamine were lower for P1END compared with P2END. Succinate was lower for P1END compared with P3END. Asparagine and lactate were lower for P1END compared with P2 END and P3END. Those findings suggest that during a 4 km TT, the level of neuromuscular fatigue is established at P1END and maintained until the end of the exercise task. Moreover, the metabolimic profile might be associated with oxidative metabolites and other relevant markers for central nervous system, which may act as feedback to control the exercise intensity

No description available.

É reconhecido que as técnicas de enriquecimento ambiental são importantes ferramentas para a melhoria do bem-estar de animais cativos. No entanto, questões em torno da efetividade e temporariedade dos efeitos das práticas requerem investigação e aprimoramento. O presente estudo foi realizado com o objetivo de analisar a influência de diferentes tipos de enriquecimentos, assim como o tamanho do recinto no comportamento de felinos em cativeiro. O estudo foi dividido em três partes, na primeira, buscou-se analisar se um enriquecimento classificado como intrínseco (catnip) e outro extrínseco (quebra-cabeça alimentar) apresentaram efeitos na expressão de comportamentos direcionados ao enriquecimento e de pacing em jaguatiricas (Leopardus pardalis) quando aplicados por meio de frequências de exposição consecutiva (sete dias) ou intermitente (a cada dois dias). A segunda parte do estudo concentrou-se em investigar se jaguatiricas alojadas em recintos maiores apresentaram diferenciada expressão de pacing em comparação àquelas residentes em recintos menores, sob duas condições: sem aplicação (linha de base) e com aplicação de enriquecimento (catnip e quebra-cabeça alimentar). Por fim, a terceira parte investigou se três enriquecimentos intrínsecos (bola de feno sem odor, com catnip e canela) influenciaram de forma distinta os comportamentos de guepardos (Acinonyx jubatus) e tigres de Sumatra (Panthera tigris sumatrae) em termos da expressão dos comportamentos de pacing, locomoção, inatividade, exploração e comportamento direcionado ao enriquecimento. Em síntese, os resultados indicaram que as dimensões dos recintos influenciaram no comportamento de pacing em jaguatiricas, apresentando maior ocorrência de pacing nos indivíduos alojados em cativeiros pequenos. O enriquecimento extrínseco utilizado (quebra-cabeça alimentar) demonstrou efeito de longa duração em comparação ao intrínseco (catnip), em termos de tempo de interação, assim como, indicaram maior influência na redução da expressão da estereotipia. Por outro lado, os enriquecimentos intrínsecos aplicados no estudo demonstraram um efeito de curto prazo para os comportamentos direcionados ao enriquecimento, contudo, a essência de canela reduziu significativamente os níveis de pacing em guepardos e tigres de Sumatra. Em termos de frequencia de exposição, os felinos não demonstraram efeitos de habituação aos estímulos apresentados entre sessões (ao longo do período experimental), para ambas as condições de apresentação (consecutiva e intermitente). As descobertas do presente estudo contribuíram com a resolução de questões relacionadas ao aprimoramento da ciência do enriquecimento. Dentre estas destacam-se: 1) tipos diferentes de enriquecimentos demonstraram causar efeitos distintos no comportamento dos animais, sugerindo que as práticas devem ser em aplicadas para atingir objetivos específicos de acordo com os efeitos provocados (longo-prazo, curto-prazo e/ou redução de estereotipias); 2) características ambientais, como o tamanho do recinto, podem influenciar o comportamento de animais que ocupam grandes extensões em relação a comportamentos anormais; e por fim 3) a complexidade proporcionada pelo enriquecimento pode minimizar esses efeitos maleficentes. Os resultados apresentados nesta pesquisa destacam a importância de investigações focadas no impacto das características do recinto, eficácia do enriquecimento nas interferências comportamentais e no design metodológico, a fim de atender às necessidades comportamentais dos animais em cativeiro. / Environmental enrichment techniques have been shown to be a powerful tool to improve the welfare of captive animals. However, many issues regarding effectiveness and temporality of the effects on behavioural interference require investigations and improvement. This study was conducted to analyse how environmental enrichments classified as intrinsic and extrinsic, as well the enclosure sizes influence the behaviour of wild cats kept in captivity. In the first part of this study the effects of an intrinsic (catnip scent) and an extrinsic (puzzle-feeder) environmental enrichment on the duration of enrichment-directed and pacing behaviours in captive ocelots (Leopardus pardalis), considering two application schedules, consecutive (seven days) or intermittent (every two days) was addressed. In the second part it was investigated if the enclosure size affects the duration of pacing behaviour by ocelots kept under enriched (catnip and puzzle-feeder) and non-enriched (baseline) environmental conditions; and in the third part it was tested if three intrinsic enrichments (hay balls without scent, with catnip and with cinnamon) had distinct effects on cheetahs (Acinonyx jubatus) and Sumatran tigers (Panthera tigris sumatrae) behaviour regarding pacing, locomotion, inactive, exploratory and enrichment-directed behaviours. In summary, results demonstrated that the enclosure size have a high impact in the duration of pacing behaviour expressed by the ocelots. The extrinsic enrichment (puzzle-feeder) presented a long-term effect on ocelots behaviour, resulting in a reduction of pacing time. On the other hand, the intrinsic enrichments promoted a short-lived effect in cheetahs and Sumatran tigers, and cinnamon demonstrated a better influence on the reduction of pacing behaviour than catnip. In terms of frequency of exposure the wild cats did not get habituated to the practices between sessions (over experimental days), for either consecutive or intermittent application schedules. The findings presented here elucidated issues related to enrichment science improvement. Among these stand out: 1) different types of practices cause distinct effects on animals behaviours, and should be applied according to the aim proposed to achieve (long-term, short-term or stereotypy reduction); 2) enclosure sizes can influence the behaviour of wide-ranging animals kept in captivity; and 3) the environmental complexity, provided by the environmental enrichment practices, reduces the negative effect of small sized enclosures in ocelots. The presented outcomes highlight the importance of investigations focused on the impact of enclosure features and the efficacy of environmental enrichment and methodological design for its application for the welfare of captive animals.

Spatio-temporal variation in activation rates during ventricular fibrillation (VF)provides insight into mechanisms of sustained re-entry during VF. This study had three objectives related to spatio-temporal dynamics in activation rates during VF. The first objective was to quantify spatio-temporal variability in activation rates,that is, in dominant frequencies, computed from epicardial electrograms recorded during VF in swine. Results showed that temporally and spatially, dominant frequencies variedas much as 20% of the mean dominant frequency, and the mean dominant frequencies increased during first 30 sec of VF. These results suggest that activation rates are nonstationary during VF. The second objective of the study was to develop a new stimulation protocol for quantifying restitution of action potential duration (APD) by independently controlling diastolic intervals (DI). A property of cardiac cells that determines spatio-temporal variability in dominant frequencies is restitution of APD, which relates APD to the previous DI. Independent control of DI permits explicit determination of the role of memory in restitution. Restitution functions quantified using mathematical models of activation and our stimulation protocol, showed significant hysteresis. That is, for adiastolic interval, the action potential durations were as much as 15% longer during periods when the DI were decreasing than when the DI were increasing. We verified the feasibility of implementing our protocol experimentally in isolated and perfused rat hearts with action potentials recorded using floating glass microelectrodes. The third objective of our study was to verify that spatio-temporal variability in dominant frequencies during VF could be modified using spatially distributed pacing strength stimuli. Simulated VF was induced in 400x400 and 400x800 matrices of cells. Electrical function of cells was simulated using the Luo-Rudy model. Stimulators were arranged in the matrices such that there were 5 rows of line stimulators. Results showed that it was possible to modify activations in almost 54% of the area and to modify spatio-temporal variability in activation during VF into a desired pattern by the use of synchronized pacing from multiple sites. These results support further exploration of distributed stimulation approach for potential improvements in defibrillation therapy.

The aim of this thesis was to directly test the key underpinnings of recent propositions for systems of central control of exercise regulation. Fatigue and exercise tolerance have traditionally been explained through peripheral mechanisms, such as excitation-contraction coupling failure and the inability to supply sufficient metabolic substrate to contracting muscle in order to meet increasing energy demand. More recently, models of central control, which are proposed to regulate exercise intensity in an anticipatory/feedforward manner, with the ultimate aim of avoiding physiological ‘catastrophe’, have received a great deal of attention. This thesis investigated several of the key requirements and mechanisms stated in these models. The central governor model (CGM) and teleoanticipation are stated to use a combination of prior experience and distance knowledge of an exercise bout to work in a feedforward manner, so that a pacing strategy is set before exercise commences which ensures the bout is completed in an optimum time but in the absence of premature fatigue. Study one examined the influence of distance knowledge, prior experience and distance feedback on the setting and regulation of a pacing strategy in 4 km time trial (TT) cycling in trained cyclists (n = 18). When performing 4 × 4 km TT intervals, it was found that prior experience of the exercise (in the absence of distance feedback and distance knowledge) allowed the creation of a pacing strategy that produced a performance which was as competitive as cyclists who were provided with prior experience, distance knowledge and distance feedback. The difference in TT completion time between groups (CON = feedback group, EXP = no feedback group) was reduced with subsequent TT (CON TT1 367 ± 21 s; EXP TT1 409 ± 45 s; CON TT2 373 ± 19 s; EXP TT2 389 ± 30 s; CON TT3 375 ± 18 s; EXP TT3 383 ± 26 s; CON TT4 373 ± 20 s; EXP TT4 373 ± 14 s), so that by the final TT, completion time between groups was almost exactly the same. It was concluded that when sufficient prior experience is attained in the absence of distance knowledge and feedback, a successful pacing strategy can be set. In order for pacing to be set prior to an exercise bout and adjusted in a feedforward/anticipatory manner during exercise, an internal mechanism must exist which monitors the passage of time. Study two examined the accuracy and robustness of this ‘internal clock’ by assessing cyclist’s (n = 16) ability to gauge the distance they had cycled during repeated 4 km and 6 km TT. The internal clock was shown to be inaccurate to absolute measures of distance, but showed a calibration capacity following experience of a TT of unknown distance (24.6 ± 18.2 % error in distance judged completed vs. 8.2 ± 5.5 % error in distance judged completed). This process was fragile and occurred in the absence of any significant performance improvement. It was concluded that relative quantities appear more important in creating a pacing strategy, and that times are of greater importance than distances. Study three examined the influence of comparative performance feedback in a field setting in 4 km track TT cycling in trained cyclists (n = 5). Correct feedback produced a significantly faster TT time (t4 = -3.10, p < 0.05) than non-contingent feedback (341 ± 8 s vs. 350 ± 12 s), with differences in mean lap speed apparent between the conditions at the start of the TT (t4 = 4.71, p < 0.05) and at the end of the TT (t4= 3.45, p < 0.05; t4 = 3.30, p < 0.05). The study provided empirical support for the assumption that performance feedback is advantageous during exercise and provided insights into past and present exercise comparison and its role on the setting of a pacing strategy. A central component of the CGM and theories of central exercise regulation is the role of afferent feedback during exercise and the premature termination of exercise before a true maximum intensity has been reached. Study four used acetaminophen to blunt cyclists’ (n = 13) pain response during ten mile (16.1 km) TT in order to disrupt the afferent feedback processes. When using acetaminophen, cyclists produced significantly faster (t12 = 2.55, p < 0.05) TT completion times (1575 ± 96 s) than under a placebo condition (1605 ± 122 s). When using acetaminophen, cyclists had a higher power output during the middle section of the TT (F1, 12 = 4.79, p < 0.05), yet showed no significant difference in RPE (F1,12 = 0.72, p > 0.05) or pain scores (F1,12 = 0.30, p > 0.05). It was concluded that acetaminophen reduced levels of pain during the TT, thereby disrupting the comparative afferent feedback mechanism and allowing cyclists access to a ‘metabolic reserve’. The research presented has advanced our knowledge and supported propositions of models of central control and regulation during exercise. The research has provided further insight in the role of prior experience, distance knowledge, distance feedback, the internal clock, performance feedback and afferent feedback on the setting and maintenance of a pacing strategy in 4, 6 and 16.1 km TT cycling.