Dissertations / Theses: 'Exercise medicine'

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Edmunds, Kim. "Cost-effectiveness of exercise medicine for prostate cancer." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2021. https://ro.ecu.edu.au/theses/2405.

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Background Androgen deprivation therapy (ADT) is associated with numerous adverse effects that impact on quality of life and contribute further to the cost burden of prostate cancer (PCa) via treatment and supportive care. Exercise medicine is effective in slowing PCa progression, reversing treatment adverse effects and improving quality of life and survival of patients, however, no economic analyses have been conducted to determine whether exercise is cost-effective in this population. Objectives Firstly, to examine the adverse effects of ADT for PCa and the evidence supporting the use of exercise medicine in their management. Secondly, to conduct the first economic evaluations of exercise medicine in the management of the adverse effects of ADT for PCa to strengthen the evidence base for the development of effective health policy around exercise and PCa survivorship. Methods A systematic review was conducted to determine the incidence of the adverse effects of ADT for PCa. A rapid review examined the role of exercise in managing these adverse effects. Three economic evaluations were then conducted to determine the cost-effectiveness of supervised exercise for men with PCa receiving ADT. Two trial-based cost-effectiveness analyses (CEAs) compared exercise training and usual care (a suggestion to exercise). The first involved a preliminary randomised controlled trial (RCT) of exercise for 20 men with metastatic PCa. A value of information (VOI) analysis was also conducted to examine the need for and value of a larger trial. The second CEA involved a RCT of exercise for men previously treated with radiation therapy and ADT. For the third economic evaluation, a decision analytic Markov model was constructed to evaluate the cost-effectiveness of an exercise intervention in preventing falls and fractures for men with localised or locally advanced PCa receiving ADT. All economic analyses were conducted from a healthcare payer perspective and the primary outcome measure was quality adjusted life years (QALYs) gained. Uncertainty in the results was explored using deterministic univariate and probabilistic sensitivity analysis where appropriate. Results The systematic review generated incidence evidence for nine adverse effect groups and 19 sub-groups, with statistically significant increased risks in 17 sub-groups. The rapid review revealed that exercise was effective in improving body composition, physical function and fatigue, as well as mitigating the bone loss, sexual dysfunction and psychosocial effects associated with ADT. The first within-trial CEA of exercise for men with metastatic PCa resulted in an incremental cost-effectiveness ratio (ICER) of $133,509 and a 30% probability of being cost-effective after three months at a willingness-to-pay of AU$50,000. VOI analysis suggested further research is likely to be cost-effective to conduct. The second within-trial CEA of exercise for men who received radiation therapy and adjuvant ADT for localised PCa resulted in an ICER of $64,235 and a 41 per cent probability of cost-effectiveness after six months at a willingness-to-pay of AU$50,000. For the modelled cost-utility analysis, the exercise intervention dominated usual care (a suggestion to exercise), as it was less costly and more effective. Net monetary benefit (NMB) was $102,112 and probabilistic sensitivity analysis showed a 58% probability of cost-effectiveness at a willingness-to-pay of AU$50,000. Conclusion This research is the first to examine the cost-effectiveness of exercise for men with PCa receiving ADT. Supervised exercise is effective in managing many adverse effects of PCa treatment and cost saving in preventing falls and fractures. Future efforts need to focus on strengthening the evidence base in exercise for ADT adverse effect management. Uncertainty in economic evaluation can be reduced with more comprehensive cost and outcome data, longer follow up and larger sample sizes. This research has the potential to translate into changes in clinical practice, better informed policy decisions, cost savings for healthcare payers, and ultimately, better health and quality of life for PCa patients, survivors and their families.

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Rogerson, Michael. "Green exercise : combined influence of environment and exercise to promote wellbeing." Thesis, University of Essex, 2016. http://repository.essex.ac.uk/17575/.

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Exercise participation is linked to mental health and wellbeing. However, we need to identify optimal settings for promoting exercise-associated wellbeing outcomes, and for promoting exercise adherence. The literature suggests environmental settings may be important. The aim of this thesis was to rigorously test influences of environmental settings on exercise-related wellbeing outcomes. These over-arching research questions guided the experimental chapters: (i) is there an optimal green exercise environment for promoting wellbeing? (ii) When exercise is controlled, are findings consistent with previously reported psychological outcomes? (iii) Do environmental settings influence social outcomes of exercise or intentions to repeat exercise behaviours? Via field-based sampling, Chapter 3 found large proportions of affective benefits were universally obtainable across four typical green exercise environments, and suggested that the processes component of green exercise warranted further investigation; however, this method lacked control. Chapter 4 used laboratory-based methodology to control exercise and isolate the visual environment; consistent with both theory and previous research, nature environments facilitated wellbeing-related attention restoration. However, this method did not provide an accurate multisensory experience, therefore lacking ecological validity. Chapter 5 investigated methodologies for controlling the exercise component, comparing wellbeing-related outcomes of indoor versus outdoor exercise. This was important because previous research had not rigorously controlled exercise, therefore potentially confounding its findings. Results for environment-related exercise differences and affective outcomes were inconclusive. Chapter 6 merged laboratory-based methods with the indoor versus outdoor exercise paradigm, ensuring control and ecological validity. Environmental setting did not influence perceived exertion or mood; green settings promoted attention restoration and social interaction; for green exercise, social interaction predicted exercise intentions. Green exercise promotes wellbeing improvements; environmental influences on affective outcomes may be contributed to by differences in exercise performed. Independent of exercise differences, green environments promote attention restoration and social interaction during exercise, which may in turn influence exercise intentions.

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Wall, Bradley A. "Exercise as medicine : reversing treatment toxicities in prostate cancer patients." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/691.

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A common treatment for prostate cancer, which is the most common form of cancer after skin cancer in Australian males, is androgen deprivation therapy (ADT). However, ADT is associated with an array of adverse effects including reduced bone and lean mass, loss of muscle strength, negative change in lipid profile, and increased risk of cardiovascular disease (CVD) as well as diabetes, all of which can compromise physical function and quality of life. Physical exercise has been suggested as a key lifestyle intervention for this group of cancer patients as it has enormous potential to limit and even reverse the effects of such treatment toxicities. This thesis is comprised of a review of the literature and three experimental chapters examining the effects of androgen deprivation therapy (ADT) and the role of exercise in ADT treated prostate cancer patients. The review of literature provides a background to cancer, in particular prostate cancer and the commonly reported side effects of treatment. The review identified gaps in the literature that highlighted the need for well controlled and longer term experimental studies to: 1) investigate the impact of androgen deprivation therapy duration on cardiovascular and metabolic outcomes, and 2) investigate the effects of a long term exercise intervention in reversing cardiovascular risk factors and unfavourable alterations in the metabolic profile. Study 1 examined the feasibility and safety of a maximal treadmill exercise test in ADT treated prostate cancer patients as this was a key assessment of physiological response to the exercise intervention. One hundred and twelve prostate cancer patients undergoing ADT took part in a physician supervised multistage maximal stress test (Bruce protocol). Of these men, 85% were able to meet the criteria for the attainment of VO2max whilst three positive tests (3.2%) were observed. The three participants who recorded a positive stress test were sent for further examination and subsequently cleared of any serious issues. Apart from the relatively low VO2max (10-15th percentile), compared to healthy age matched controls, the cardiovascular response to exercise is similar in this cancer population. Maximal exercise testing in this population was demonstrated to be feasible and safe providing a direct assessment of VO2max whilst treatment duration did not appear to influence the cardiovascular responses to exercise. Study 2 was a cross-sectional design comparing chronic versus acute ADT treated patients to examine if therapy time exposure leads to additional risk factors for CVD and metabolic toxicities in prostate cancer patients. One hundred and seven men undergoing ADT for treatment of prostate cancer were stratified into two groups, either acute (months) or chronic (>3 months) exposure. Chronic ADT exposure was associated with a 17% reduction maximal aerobic capacity (-0.4 L.min-1) and an 8% reduction in resting metabolic rate (-147 kcal/24hr). The chronically exposed group also exhibited 8-22% lower maximal strength values (chest press -5.9kg, seated row -3.9kg, leg press -27.5kg and leg extension -12.2 kg) and a corresponding decrement in physical function variables ranging from 9-16% (400m walk +24.9s, chair rise +2.0s, and stair climb +0.7s). Whilst not significant, there was also a trend towards a decrease in lean mass of 3.5% (-2.1kg) and an increase in fat mass of 6.5% (1.5kg) in the chronically suppressed group. ADT exposure did in fact have a negative effect on CVD risk factors as well as physical function outcomes. Whilst the exact mechanisms remain unclear as to why these cardiovascular alterations and physical function variables are further declining as treatment time progresses, it is possible that factors other than those assessed in this study, such as reduced physical activity levels, may have influenced the results. Study 3 utilised a randomized controlled trial (RCT) study design to examine the long-term effects (6 months) of a combined aerobic and resistance training intervention in reducing or stabilizing CVD and diabetes risk factors in men receiving ADT. Participants were randomly allocated to either an exercise (EX) group (n= 50) or a control (CON) group (n= 48). The combined aerobic and resistance training program consisted of twice weekly clinic based sessions at which the participants completed 20mins of aerobic activity (70- 90% maximal intensity) and 6 resistance based exercises targeting the major upper and lower body muscle groups. In addition, participants were prescribed a home based training program consisting of 110 minutes of aerobic activity. The control group were instructed to adhere to their usual lifestyle and care routine. Body composition [lean mass 1.1% (+0.8kg), fat mass -4.2% (-1.1kg) & body fat -3.8% (-1.1kg], muscular strength [chest press 9.6% (+3.6kg), seated row 7% (+6.0kg), leg press 14.8% (+20kg) & leg extension 19.4% (+10.2kg)], muscular endurance [chest press 49.4% (+5.0 reps) & leg 49.9% (+7.7 reps)] and 400m walk [-4.8% (-13s)] significantly improved (p This research has demonstrated that: 1) maximal cardiorespiratory exercise testing is safe and feasible in this population, 2) prolonged exposure to androgen deprivation therapy (>3 months) has a negative impact on a number of cardiovascular, metabolic and physical function outcomes, and 3) a combined aerobic and resistance training program can be safely undertaken in men undergoing ADT and results in an array of benefits for cardiovascular and metabolic outcomes as well physical function. As a result of these findings, patients prescribed ADT for the treatment of prostate cancer should be appropriately counselled as to the negative side effects commonly associated with this form of treatment and be made aware of the safety and beneficial effects an appropriately administered exercise intervention can have on reversing these adverse alterations occurring throughout the course of treatment. Further, these specifically designed exercise interventions should be commenced as soon as practically possible post prostate cancer diagnosis and continue for the course of treatment and ideally beyond.

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Ting, Justin William. "The infrastructure of sport and exercise medicine in Canada." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/43939.

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Currently, the Canadian Academy of Sport and Exercise Medicine (CASEM) is seeking special designation for sport and exercise medicine (SEM) from the College of Family Physicians of Canada. Infrastructure is a key criterion in a medical discipline recognition model. The purpose of the study is to evaluate the infrastructure of Canadian SEM in a quantitative and qualitative manner using a mixed-method study of a cross-sectional survey and focused interviews. The survey study examines the demographics, physician practice profiles, academic presence, research activity and organizational presence of Canadian SEM physicians. The focused interviews examine the promoters and barriers of providing SEM education, providing event coverage and conducting SEM research; and the benefits of SEM organizational bodies to the practice of SEM. The survey response rate was 55%. There is a national distribution of SEM physicians. The majority of respondents act as consultants and dedicate the majority of their practice to SEM. Eighty-six percent of respondents teach SEM and teaching is primarily done in a clinical setting. The post-secondary affiliation of a physician and the population size of where a physician practises predict the amount of time that a physician dedicates to clinical teaching and research. Approximately half of the respondents provide event coverage in a typical week and nearly one-third of respondents had conducted research within the past five years. Various forms of enjoyment are the main promoters for teaching, event coverage and research while lack of financial compensation and time are the main barriers to these activities. Interviewees appreciated SEM organizations for network and educational opportunities and identified many areas for improvement. The current SEM physician demographics, geographic distribution, practice profiles, and support from other health professionals indicate that SEM has sufficient infrastructure to support a focused practice. There is a willingness to teach among SEM physicians; however, there may be a need for stronger SEM curriculum in medical education. The barriers to SEM teaching, event coverage and research will need to be addressed to progress Canadian SEM. Professional SEM organizations are managing SEM physician activities and are viewed as leaders to promote SEM as a profession.

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Clark, Andrew Lawrence. "Exercise limitation in chronic heart failure." Thesis, Imperial College London, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389907.

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Shaw, Aaron P. "The Effect of a Pre-Exercise Nutritional Supplement on Muscle Fatigue During Handgrip Exercise." University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1373030510.

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Miner, Jared Todd. "Enabling Exercise Prescription: Developing a Comprehensive Intervention Strategy for Exercise Counseling and Prescription in Family Medicine." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1302270180.

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Mann, Steven. "An ecologically valid assessment of the 'exercise is medicine' hypothesis." Thesis, University of Greenwich, 2014. http://gala.gre.ac.uk/13589/.

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Widespread physical inactivity and resultant increases in cardiovascular and metabolic disease is a serious public health concern in the developed World. Unsurprisingly, the vast majority of research evidence suggests that physical activity is an effective intervention in addressing this state of affairs. An apparently strong case exists for the widespread clinical prescription of physical activity (PA). The application of PA in both preventative and remedial health is often termed ‘exercise is medicine’. Whilst on the basis of a large volume of laboratory data there is some consensus regarding the optimal delivery of health related PA, there is an apparent discrepancy between data emanating from laboratory and/or clinical studies and those emanating from real world interventions. In short, real world interventions do not appear to be as effective in promoting health as laboratory research suggests should be the case. This situation is compounded by a relative paucity of peer reviewed research studies reporting real world PA research, and furthermore by even less clinically relevant data. On this basis, a clear picture of the degree of translation from laboratory to the field is not yet possible. It is however not unreasonable to argue that the setting of the vast majority of research studies investigating the exercise is medicine hypothesis - that is laboratories, hospitals and clinics – might theoretically limit the translation of these findings to real world public health settings, and on that basis, more real world research is warranted. In Chapters 1 and 2 of this thesis the above arguments are developed into a case for a large scale ecologically valid translational study to investigate the effects of exercise on clinically relevant health variables. Chapter 3 presents the results of a pilot study that assessed the comparative effectiveness of structured PA (STRUC), unstructured PA (FREE), and PA counselling (PAC), among sedentary individuals in a community fitness centre setting. Significant improvements were observed in cardiovascular risk factors in all three groups, with no significant between-group differences. Chapters 4, 5 and 6 report data from a large scale, ecologically valid, longitudinal (48 week), multi-centre (n=26) investigation comparing the three interventions above with a measurement only condition. Participants were 1146 previously sedentary individuals. The ecological validity of the exercise is medicine hypothesis was tested from a clinical (Chapter 4) and behavioural (Chapter 5) perspective. Survey data pertaining to factors influencing the effectiveness of the interventions are explored in Chapter 6. Data suggest that the baseline health status of participants mediated effects over time, with participants most at risk of cardiovascular disease experiencing clinically significant improvements in health (e.g. VO2max: STRUC High -7.52% vs Low 32.03% (P=0.005), FREE High -4% vs Low 24.31% (P=0.023), PAC High -8.19 vs Low 35.8% (P=0.007), COM High -5.22% vs Low 8.17% (P=0.663)). These effects differed by condition. Improvements in body composition and VO2max following STRUC are consistent with previous laboratory findings. However, behavioural data indicate a stark contrast between retention rates observed in the current study and those reported elsewhere in laboratory studies (STRUC 34%, FREE 34%, PAC 29%, COM 31%). Post intervention survey data suggest that engaging with previously sedentary and/or low fitness participants within a fitness facility is challenging, and that as a consequence necessary levels of communication and motivation can be difficult to maintain. Overall data highlight several factors that differ between laboratory research and real world practice. These collectively potentially reduce the ecological validity of the exercise is medicine hypothesis. It is suggested that more real world research is warranted to better identify factors that might both mediate and moderate the relationship between physical activity and health.

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Witard, Oliver Charles. "Protein feeding and exercise recovery." Thesis, University of Birmingham, 2009. http://etheses.bham.ac.uk//id/eprint/508/.

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The importance of protein feeding for maximising the anabolic effect of resistance exercise is well established. Ingestion of amino acids or intact protein sources with and without carbohydrate during exercise recovery further stimulates muscle protein synthesis. Less clear is the impact of an acute bout of resistance exercise on the protein synthetic rate of muscle already stimulated by food intake. This thesis demonstrates that an acute bout of resistance exercise further augments the protein synthetic rate of muscle already stimulated by food intake. Simulating everyday practice, whereby resistance exercise is typically performed in the fed state, an exercise-induced elevation in muscle protein synthesis was accompanied by an increased phosphorylation status of signaling proteins downstream of mammalian target of rapamycin (mTOR). Recent studies advocate the potential role for protein feeding in improving subsequent performance following acute bouts of fatiguing endurance-type exercise. However, previous studies have focussed upon carbohydrate nutrition, rather than examining the role of protein feeding for exercise recovery in the context of an intense period of endurance training. Increasing dietary protein intake partially countered the blunted minimal mobilisation of antiviral lymphocytes during exercise following intensified training. In addition, the number of negative symptoms of psychological stress experienced following intensified training was attenuated with additional dietary protein intake. The mechanism(s) underpinning the suggestion that a high protein diet may potentiate a better maintainence of endurance performance following intensified training could not be definitively elucidated from our experimental design. The most likely explanation appears to be related to psychological status.

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Westergren, Jens. "Sodium bicarbonate ingestion increases pH in blood but does not attenuate exercise induced arterial hypoxemia or enhance performance." Thesis, University of Gävle, Department of Caring Sciences and Sociology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-434.

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Introduction: The exact causes of Exercise Induced Arterial Hypoxemia (EIAH) are not yet known. Earlier studies on the ergogenic effects of NaHCO3 have neglected to investigate the occurrence of EIAH among their subject, something that could explain the conflicting results, EIAH cannot be over looked since reportedly 50% of well trained athletes experience EIAH. One possible ergogenic effect of NaHCO3 would be to attenuate EIAH through an increase in blood pH in a subject. This has been shown previously by means of intravenous infusion during maximal rowing.

Aim: The aim of the study was to examine the effect of oral intake of NaHCO3 on EIAH and performance in trained cyclists.

Method: Seven male cyclists (age 23.7 (22-27) years, VO2peak 64 (60-72) ml min-1 (kg body mass) -1 volunteered for the study. The subjects performed two maximal exercise tests to exhaustion 48 hours apart in a counter balanced cross over double blind fashion. Subjects received 0.3 g kg BW-1 CaCO3 and 0.3 g kg BW-1 NaHCO3 in the placebo and bicarbonate trial respectively.

Free flowing arterialized capillary blood was sampled at rest and exhaustion and analyzed for pH, O2 Saturation, pO2, pCO2, and blood lactate. Ventilatory variables were measured continuously throughout the test V'O2, V’CO2, V'E, V'E/VO2, RER and HR. In addition pulse oximetry was used to evaluate O2 saturation.

Results/Discussion: At rest pH and PCO2 was elevated (p<0.05) in the bicarbonate trial compared to the placebo trial. At exhaustion in the bicarbonate trial pH, blood lactate, RER, was significantly elevated (p<0.05) when compared to the placebo trial. O2 saturation from blood samples at exhaustion in the bicarbonate trial showed a trend towards improving (p=0.061). No difference was seen between the two trials in PO2, VO2peak, V'Emax, HRmax or performance. During exercise, bicarbonate ingestion increased blood pH but did not improve arterial saturation or performance. The increase in blood pH achieved by ingestion of bicarbonate was not as large as the increase achieved by intravenous infusion in another study. Even with the larger increase in blood pH in those studies, there was only a small improvement in performance. One possible explanation for the performance improvement with bicarbonate infusion in that study was a reduced ventilation that could effect respiratory muscle work and thereby work capacity. The bicarbonate ingestion in the present study did not reduce ventilation. This could possible be achieved with higher doses of NaHCO3, which would most likely result in increased frequency of gastrointestinal distress among subjects.

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Thomson, Stephen D. "Exercise testing and non-invasive haemodynamics in the assessment and monitoring of pulmonary hypertension : novel submaximal and peak exercise variables." Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/8918/.

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Pulmonary hypertension is a disease characterised by progressive pulmonary vascular remodelling and obliteration with consequent development of right heart failure and ultimately death. First described many decades ago with a median survival of less than 3 years and no available treatments, the development of disease specific pulmonary vasodilator therapy has led to only modest improvements in survival and it remains an almost universally fatal disease. One of the key symptoms of pulmonary hypertension is exercise intolerance, primarily a consequence of the underlying right ventricular failure and an inability to augment stroke volume on exercise. The gold standard diagnostic test is right heart catheterisation but this is unattractive as a tool for ongoing monitoring as it is invasive and not without risk, albeit that risk is small. As a result most monitoring of disease progression and of treatment response is carried out using surrogate markers, often exercise based such as the 6 minute walk test. Increasing attention is focused on the role of exercise both in that monitoring of patients and also in helping to understand better the pathophysiology. The work presented in this thesis therefore aimed to explore novel exercise derived variables and noninvasive haemodynamic measurement as tools to improve our understanding of the disease limitation, to enhance our monitoring of treatment response and to give additional prognostic information. In Chapter 3 the role of peripheral muscle oxygen extraction and exercise limitation was explored by performing right heart catheterisation on exercise with measurement of mixed venous oxygen saturation. This demonstrated that patients with pulmonary hypertension demonstrate no evidence of impaired oxygen extraction and that they appear to extract at least as much oxygen on exercise as healthy individuals have been shown to in other studies. This indicates that impairment of oxygen extraction is not a cause of exercise limitation in pulmonary hypertension. 3 Chapter 4 describes a series of studies evaluating the potential role of the oxygen uptake efficiency slope in pulmonary hypertension. This variable derived from the oxygen consumption and ventilation across an incremental cardiopulmonary exercise test has demonstrated promise as a potential submaximal measure of exercise performance and predictor of survival in left heart failure. The studies conducted demonstrated that this variable is a measure of peak exercise performance in pulmonary hypertension, that it can be measure on submaximal levels of exercise and that it predicts survival in patients with Group 1 and Group 4 disease. The studies described in Chapter 5 investigated the rates of recovery of heart rate and oxygen consumption after exercise and found that both could predict survival. In particular the rate of recovery of heart rate after exercise was demonstrated to be a strong predictor of survival on multivariate analysis, thus providing a further method of assessing prognosis with exercise. Finally the ability of noninvasive measures of stroke volume to predict outcome was explored in the studies detailed in Chapter 6. The underlying haemodynamic abnormalities are not assessed when surrogate measures such as exercise testing are employed in patient follow up. Standard practice is to review patients 3 to 4 months after any change in treatment and to assess them using these surrogate measures. Acute haemodynamic changes are able to be detected invasively immediately after administration of pulmonary vasodilator therapy. This study therefore investigated the ability of two noninvasive methods of measuring stroke volume, inert gas rebreathing and cardiac MRI, to detect treatment response after only 2 weeks and assess how this related to functional improvement at the standard 4 months. The study found that haemodynamic changes were able to be detected at 2 weeks and these appeared to relate to changes in 6 minute walk distance at the same time point but did not appear to relate to 6 minute walk distance at 4 months. This study however did not reach its recruitment target and therefore further work is needed in this area.

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Cocking, S. "Enhancing exercise performance through ischaemic preconditioning." Thesis, Liverpool John Moores University, 2019. http://researchonline.ljmu.ac.uk/9835/.

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Ischaemic preconditioning (IPC) is an intervention whereby brief intermittent ischaemic episodes are induced in a limb (usually 4x5-minute arterial occlusion bouts, interspersed with 5-minutes of reperfusion) either at the site of interest (IPC), or at a distance from the site of interest (Remote; RIPC). Although originally linked to cardiology, recently studies have investigated the effects of IPC administered on a limb prior to exercise with some showing improvements in exercise performance. The overarching aim of the present thesis was to investigate how to optimise IPC to further enhance exercise performance. The optimal protocol of IPC on exercise performance was quantified by manipulating: 1. the number of cycles, 2. amount of muscle tissue, and 3. local vs Remote occlusion, which were applied in a randomized counterbalanced order in study 1 (Chapter 3). IPC dose, location and occlusion area differed prior to a 375 KJ time trial (TT) performance in 12 trained men. The traditional 4x5-min IPC stimulus resulted in the fastest TT time compared to SHAM [17 secs (90% CI: 0, 34 secs); P=0.097], but there was no benefit of applying a greater number of cycles [5 secs (-35, 26 secs); P=0.49] or employing unilateral IPC [18 secs (-11, 48 secs, P=0.29]. Local versus Remote cuff placement did not result in changes in TT time [0 secs (-16, 16 secs; P > 0.9]. Overall, regardless of location, the 4x5-minute dose seemed to provide the most benefit to exercise performance. The ability of IPC to enhance exercise capacity may be mediated through altering exercise-induced blood flow and/or vascular function. Study 2 (Chapter 4) investigated the blood flow response to exercise, using ultrasound, when exercise was preceded by a control (SHAM) condition, or either local or Remote (R)IPC in eighteen recreationally trained males. Vascular 4 function tests were also performed before SHAM and (R)IPC and at the end of exercise. IPC resulted in enlarged brachial artery diameter during exercise [0.016 cm (0.003 to 0.03 cm); P=0.016] compared to RIPC, but blood flow during exercise was similar between conditions. No changes in post-exercise vascular function were observed between conditions. Therefore, enhanced vasodilation following local (but not Remote) IPC, when performed prior to exercise, does not translate into increased blood flow during exercise nor impact post-exercise vascular function. IPC could alleviate deleterious muscle damage responses after exercise-induced muscle damage (EIMD; often lasting < 72 hours). Study 3 (Chapter 5) investigated whether IPC could negate eccentric exercise-induced reductions in torque production. Eleven recreationally trained males completed 200 repetitions of maximal eccentric contractions when preceded by IPC or SHAM performed in a randomized order, separated by a 9-week washout period. Muscle function tests were performed after IPC/SHAM prior to eccentric exercise and at 1-hour, 24-hours, 48-hours & 72-hours post-EIMD. Venous blood samples were taken at all time points. Greater maximal [15.2 N.m-1 (6.2 to 24.1); P=0.006] and mean [13.3 N.m-1 (5.3 to 21.3); P=0.007] torque production during a fixed angle voluntary maximal voluntary contraction (MVC) task and during a 60 deg·sec-1 [10.1 (4.9 to 15.3); P=0.002 & 9.8 N.m-1 (6.1 to 13.5; P < 0.005] isokinetic task were evident after IPC versus SHAM prior to eccentric exercise (EIMD). This was maintained throughout the (72-hour) muscle damage window. Lower cytokine (IL-6 and IL-1ra) were reported after IPC versus SHAM (P < 0.002, respectively). IPC resulted in greater overall HSP-27 & 32 levels (P < 0.01) whilst HSP-72 was lower (P=0.001) versus SHAM. Therefore, IPC can enhance maximal torque production during isokinetic dynamometry, before and after muscle damaging exercise and induce advantageous extracellular stress responses to EIMD in humans. 5 Study 4 employed IPC in a practical exercise-priming model, that aimed to maximise repeated sprint ability (RSA). Eleven trained cyclists performed 4 experimental visits in a repeated measures design. The "traditional" 4x5-minute local IPC (IPC) dose was compared to a SHAM condition (20 mmHg). IPC or SHAM were performed on two separate visits, each combined with either passive muscle heating (HEAT) on two visits, or thermoneutral (non-heated) insulation on two visits, prior to an "all out" repeated sprint task (10x6-second sprints with 24-seconds of recovery). There were no meaningful changes in 10x6-second average [12 (-7 to 31) watts; P=0.28] or peak [6 (-14 to 26) watts; P=0.62] power output following IPC versus SHAM. Additionally, no benefit was observed when muscle temperature was elevated in combination with IPC [5 (-14 to 19) watts; P=0.67], or separately to IPC [9 (-9 to 28); P=0.4] versus SHAM. Overall, it appears that IPC, nor (the combination of) muscle heating can positively impact RSA performance in trained cyclists versus a SHAM condition. The findings from this thesis suggest that using a "traditional" dose of 4x5-minute cycles, either on the legs or the arms, promote performance enhancements in aerobic tasks such as cycling TT performance. These potential performance improvements are likely not resultant from increased limb blood flow. IPC can also enhance muscle function following muscle damaging exercise and induce advantageous extracellular stress responses to EIMD. Nevertheless, IPC alone or when combined with local muscle heating likely has no meaningful enhancements in repeated sprint cycling performance. The findings from this thesis may help athletes to establish a better understanding of how IPC can be used prior to exercise.

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Cardoso, Fernando M. F. "Improving the assessment of exercise capacity and cardiorespiratory fitness in patients attending exercise-based cardiac rehabilitation." Thesis, University of Essex, 2016. http://repository.essex.ac.uk/18038/.

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The aim of this thesis is ‘’Improving the Assessment of Exercise Capacity and Cardiorespiratory Fitness in Patients Attending Exercise-Based Cardiac Rehabilitation’’. Cardiorespiratory capacity is an important predictor of morbidity and mortality in cardiac patients, due to the prognostic power, is an essential outcome to measure in cardiac patients in clinical practice. In cardiac rehabilitation programmes the assessment of cardiorespiratory capacity (by field tests or treadmill test) is an essential practice supported by U.K., European and U.S.A. guidelines, which gives support to patients risk evaluation and stratification, setting individual patients goals, exercise prescription, and evaluation of the same. Overall, the findings of this thesis, which were generate by meta-analysis, crosssectional studies and laboratory research, provide an nsight into the factors associated with patients’ initial performance, and oxygen cost in functional capacity tests. Together, this data may improve the application, interpretation and patient understanding of these test results. One aim of CR is to improve patients’ functional capacity; we provide a standard value for ΔFitness, and information on factors which clinicians may need to consider when setting patient goals and interpreting changes in functional capacity, or ΔFitness due to CR.

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Parr, Bridget Marianne. "Exercise training in patients with peripheral vascular disease." Master's thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/3448.

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Bibliography: leaves 91-98.
Patients with peripheral vascular disease (PVD) suffer from the symptom of intermittent claudication and are walking intolerant. However, it is not clear what contributes to walking intolerance in patients with PVD.

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Davies, Christopher S. "The role of oxygen-dependent substances in exercise." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4273/.

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This thesis investigated the role of O$_2$-dependent substances in mediating the vasodilatation seen following exercise (post-exercise hyperaemia) and in fatigue development. Additionally we compared young and old subjects to investigate the effects of ageing in both of these phenomena. Breathing supplementary 40% O$_2$ during handgrip exercise at 50% of maximum voluntary contraction had no effect of the magnitude of post-exercise hyperaemia compared to air breathing control. Furthermore, aspirin administration did not alter magnitude of post-exercise hyperaemia or the levels of prostaglandin E metabolites assayed from the forearm venous efflux. Similarly the magnitude of post-exercise hyperaemia was not affected by aminophylline administration. Collectively these suggest that prostaglandins and adenosine are not obligatory mediators of post-exercise hyperaemia. Supplementary O$_2$ breathed during recovery had no effect on fatigue in a second bout of exercise or any of the substances proposed to mediate fatigue, in young subjects. We demonstrated that older subjects showed no changes in the magnitude of post-exercise hyperaemia, but they were more fatigue resistant. There was no O$_2$-dependence of either post-exercise hyperaemia or fatigue in older subjects. In conclusion, we have found no evidence of O$_2$-dependent mediators in either post-exercise hyperaemia or fatigue.

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Randell, Rebecca. "Factors affecting fat oxidation in exercise." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4736/.

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Increasing fat oxidation rates during exercise may be beneficial for the athletic population. At rest, ingestion of Green Tea Extract (GTE) has been found to augment fat oxidation, but there are limited data on the effects during exercise. This thesis systematically investigated the effects of GTE ingestion on exercise metabolism in physically active males. We set out to determine if longer-term feeding of GTE could increase fat oxidation rates during a steady state exercise bout to a greater degree than an acute dose. However, irrespective of the length of ingestion no measureable change in substrate metabolism was found. Due to the large individual differences in fat oxidation at a given absolute and relative exercise intensity, we investigated the effects of acute GTE ingestion during a graded exercise test. Again, no change in fat metabolism was found over a wide range of exercise intensities. Finally, we collected fat oxidation data from a large cohort of athletes. From these data we set new criteria to define individuals as either a fat or carbohydrate metabolic type. Although it is still not known fully what determines metabolic type, the use of a nutritional intervention may be more effective in one type over the other.

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17

Williams, Arthur. "Exercise induced bronchospasm and chlorine in swimming pools." Master's thesis, University of Cape Town, 2004. http://hdl.handle.net/11427/2770.

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Includes bibliographical references (leaves 47-57).
The purpose of this thesis was firstly to review the possible relationship between chlorine in swimming pool water and exercise induced bronchospasm, and secondly to assess whether chlorine exposure during swimming provokes EIB in well-trained swimmers with and without a history of EIB.

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18

Drew, Nichola. "Exercise-associated muscle cramping (EAMC) in Ironman triathletes." Master's thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/7428.

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Includes bibliographical references (leaves 73-77).
Exercise-associated muscle cramping (EAMC) is a common condition of spontaneous, painful skeletal muscle spasms that occur in exercising muscles during exercise or in the immediate post-exercise period. There is a high prevalence in endurance athletes, including ultra-distance triathletes. The exact cause for this condition has not been defined but various hypotheses have been proposed. Over the last decade the ""fatigue hypothesis"" has received most of the support in the scientific literature. Evidence from animal experiments, clinical studies on endurance athletes and situational information, suggest that neuromuscular fatigue may precede the increased neuromuscular excitability leading to EAMC. The objective of this research study was to identify factors associated with EAMC in endurance triathletes in an attempt to further elucidate the aetiology. Triathletes competing in the 2006 South African lronman triathlon were recruited as subjects in a prospective cohort study. A total of 44 triathletes made up the cramping group and 166 the non-cramping group. A detailed questionnaire, including information on training, personal best performances and a cramping history was completed by both groups of triathletes. Full clinical data was also collected from both groups. This included pre-and post race body weights, and pre- and post-race serum electrolyte concentrations. The main findings of the study were that the two independent risk factors for EAMC in these triathletes were a faster overall race time (and cycling time), and a past history of cramping (in the last 10 races). Results showed that EAMC was correlated with faster overall and cycle section times. The athletes who had experienced cramps in this event not only achieved taster race times but also predicted faster times, despite similarly matched preparation and performance histories as those who did not cramp. A higher intensity of racing would thus be required by these athletes, predisposing them to premature fatigue. The results thus agree with the ""fatigue hypothesis"" as an aetiological mechanism for EAMC. This study also showed no correlation between EAMC and changes in hydration status or changes in serum electrolyte concentration. This study thus adds to the evidence against disturbances in hydration and electrolyte balance as causes for cramping in exercise and further focuses attention on neuromuscular fatigue as a possible primary factor.

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Myerson, Saul Gareth. "Exercise physiology and the renin-angiotensin system : role of the ACE gene insertion/deletion polymorphism in cardiac growth and endurance exercise." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270592.

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20

Drust, Barry. "Metabolic responses to soccer-specific intermittent exercise." Thesis, Liverpool John Moores University, 1997. http://researchonline.ljmu.ac.uk/5574/.

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The intermittent exercise pattern associated with soccer makes analysis of the demands of the sport more complex than in many individual sports. The aim in this thesis was to determine the physiological and metabolic responses to soccer-specific exercise. The demands associated with elite level match-play were evaluated by techniques of motion-analysis. Laboratory based soccer-specific intermittent exercise protocols were then devised to determine the physiological strain associated with soccer and investigate the effects of increased ambient temperature and whole body pre-cooling on performance. The work-rate profiles of elite South American soccer players and English Premier League players, performing in international and club level respectively, were determined. English Premier League players covered a greater total distance during a game than the South American players (P< 0.05). Differences were found for the total distance covered for playing positions with midfield players covering larger distances than forwards. Defenders covered a greater distance jogging backwards than forward players with forwards sprinting a greater distance than defenders. Work-rate was reduced in the second half of the game for all player. The total distance covered by the international players was done mainly at submaximal intensities. High intensity exercise was infrequent and bouts were of short duration. No significant correlations were observed between the work-rate profile and anthropometric charactersitics of individuals. The use of the doubly-labelled water technique to indicate the energy expenditure during soccer match-play was investigated. The doubly-labelled water technique cannot determine energy expenditure during a soccer match as the rate of turnover of the isotopes is too small to allow the accurate estimation of energy expended. Laboratory based soccer-specific intermittent protocols elicited physiological responses that were similar in magnitude and pattern to soccer match-play. Physiological demands fluctuated with exercise intensity during intermittent exercise. Oxygen consumption and heart rate were not significantly different during soccer-specific intermittent exercise and steady-rate exercise at the same average intensity. Rectal temperature did not differ significantly between the two protocols, although intermittent exercise performance resulted in a greater rise in rectal temperature as the protocol progressed (P< 0.05). Sweat production did not differ significantly between the two exercise sessions, though the rating of perceived exertion was significantly higher (P< 0.05), for the session as a whole, during intermittent exercise. Intermittent exercise performance at 26 ° C did not result in significant increases in the physiological, metabolic or thermoregulatory responses when compared to intermittent exercise at 20 ° C. The physiological and metabolic responses were also similar when intermittent exercise was performed after a whole body pre-cooling manoeuvre. Rectal temperature was lowered by the pre-cooling strategy prior to exercise (- 0.6 ± 0.6 ° C, P< 0.05). Rectal temperature during exercise was only significantly lower after pre-cooling than during exercise at 26 ° C. No significant differences were observed in rectal temperature during exercise between the normal and pre-cooled condition. The increase in rectal temperature during the second half of the protocol was significantly greater than the increase observed at 26 ° C or under normal conditions. This may be a consequence of an altered thermoregulatory response due to the pre-cooling manouvre. In conclusion, the work-rate demands of soccer seem to be predominantly aerobic in nature with anaerobic bouts and the performance of specific match activities increasing the demands placed on players. The demands of intermittent exercise are not significantly different from continuous work performed at the same average intensity though there is tentative evidence for a decrease in the efficiency of the thermoregulatory system during intermittent work. No adverse effects upon intermittent exercise performance were noted under conditions of moderate heat stress, while any thermoregulatory benefits of whole body pre-cooling during intermittent work are probably only transient.

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21

Graham, Rebecca. "Stakeholder perspectives of an exercise referral scheme." Thesis, Liverpool John Moores University, 2006. http://researchonline.ljmu.ac.uk/5778/.

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22

Alhowikan, Abdulrahman M. "Impact of exercise duration on maximal and sub-maximal markers during clinical cardio-pulmonary exercise testing." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3224/.

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Currently, the American College of Sports Medicine (ACSM) recommends that protocols for cardiopulmonary exercise testing (CPET) should last between eight and twelve minutes. However, the justification for these exercise durations rely on limited experimental data. These recommendations have a significant impact on the ability of frail patients to be assessed using CPET and should conform to evidence based practice. This thesis begins by assessing the validity of these recommendations in relation to maximal exercise responses before assessing the consequences of these recommendations on sub-maximal exercise measurements. These studies were conducted in a relatively large cohort (compared to the study that underpins the ACSM guidelines) of heterogeneous volunteers (they are both men and women, with a significant age range and varied functional capacity) to make the data more relevant to clinical exercise testing. The data presented in chapter three demonstrate that it is very difficult to obtain exercise duration conforming to the current ACSM guidelines by using a standardised ramp exercise protocol on both treadmill and cycle ergometer exercise. However, sub-group analyses for those subjects who achieved moderate (8-12 minutes) and short (less than 8 minutes) exercise durations. In addition, a separate analysis was carried out for a different sub-group of those who achieved moderate (8-12 minutes) and long (more than 12 minutes) of durations of exercise. Despite this, it was possible to demonstrate in sub-group analysis that there was no significant difference in peak oxygen uptake, peak carbon dioxide output, peak heart rate, peak ventilation and peak power output when exercise duration was less or more than that prescribed by the ACSM recommendations. In addition, the effects of long, moderate or short duration exercise per se were also analysed in this chapter and again exercise duration was shown to be without effect on the main maximal markers of exercise performance. In chapters four, five and six, the initial findings were extended to determine the effects of exercise duration on a range of clinically relevant sub-maximal markers of exercise performance. It was likely, since exercise duration did not affect maximal exercise that the physiological determinants of maximal performance were not significantly altered during short or long duration exercise and consequently it was likely that sub-maximal markers of functional capacity would not be affected. However, the quality of the data obtained during CPET can obviously influence the accurate measurement physiological responses during exercise and much of the analysis in these chapters focused on the validity of the data analysis. Chapter four investigated the limitations to measuring the break point in the relationship between oxygen uptake and carbon dioxide output during progressive exercise (the so called ventilatory threshold or ‘V-slope’). The accurate measurement of this break point was determined by standard gas exchange criteria and the effects of reducing the data available for analysis (by reducing the amount of breaths available for comparison at reduced exercise durations) were examined. The data showed that reducing the data available for analysis had an impact on the quality of the data (decreasing the goodness of fit) but no significant effect on the determination of the ventilatory threshold. Chapter five determined the effects of exercise duration on the oxygen uptake efficiency slope (OUES). As expected, the effects of exercise duration were not significant but additional investigation into the commonly employed data analysis procedures was performed. These data show that the log transformation of the relationship between ventilation and oxygen uptake allows reliable assessment of ventilatory efficiency in most cases, however, the impact of the lactate threshold on ventilation and the biological variability in where the threshold occurs as a proportion of functional capacity can impact on the sensitivity of this measurement to predict aerobic and/or anaerobic capacity. Chapter six determined the effects of exercise duration on the breathing reserve index and found no significant difference during short, moderate or long exercise duration exercise. Further analysis was performed to demonstrate limitations in the use of predicted maximum voluntary ventilation (rather than direct measurement). Taken together, these data demonstrate that the current ACSM recommendations for CPET are too restrictive and may limit the application of such testing in populations that cannot exercise for between eight and twelve minutes. The data further suggest that the testing and analysis procedures used during CPET are central to producing valid maximal and sub-maximal markers of functional capacity and the recommendations should focus include guidelines in relation to such aspects.

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23

Williams, Craig. "Peripheral muscle fatigue during intense exercise." Thesis, University of Chichester, 2005. http://eprints.chi.ac.uk/840/.

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The role of adenine nucleotide metabolism is central to the electro-mechanical processes in muscular contraction. Interventions which alter the cellular micro-environment can impact on the fatigue response during exercise possibly mediated by the balance between ATP and ADP. This thesis examined the response of biochemical and physiological markers of muscle fatigue in dietary interventions aimed to alter the cellular environment. Contractile measures included force and relaxation times from contractions of the knee extensors, whilst biochemical markers included anunonia and lactate after voluntary isometric and incremental cycle exercise. Evoked contractile measurements afforded experimental objectivity independent of voluntary intervention whilst the voluntary measures afforded greater transferability. In Chapter 3 the relaxation time response to a train of evoked fatiguing contractions varied depending on the choice of relaxation method (upper exponential, lower exponential, 60-40 exponential, 100-75,95-45,75-37.5,75-25%). Methods describing the earlier portions of the relaxation curve slowed less during fatigue than those comprising the latter portions. Intra-session variability ranged from 1.3 to 5.02% and inter-session variation ranged from 2.85 to 6.97% dependent upon the adopted relaxation method. Such variability was comparable with other laboratories demonstrating significant intervention-induced changes. This has implications for future studies in the choice of relaxation method and magnitude of change necessary for identification of intervention-induced changes. In chapter 4 the magnitudes of change in MVC and time to fatigue in a voluntary isometric contraction between creatine and placebo supplementation were -3% and 2% respectively. The fatigue-induced slowing of evoked relaxation times was greater by -4% and these changes were not significant. The differences in markers of adenine nucleotide degradation after creatine and placebo supplementation were also insignificant. In chapter 5 the creatine supplementation-induced change in the decline in evoked force during a fatiguing train was -1 % but was insignificant. For the voluntary and evoked relaxation times, in chapter 5, the magnitude of changes between placebo and creatine supplementation were <1 %, and insignificant. The ingestion of NaHCO, accelerated the loss of evoked force during a fatiguing train, with a trend towards shorter relaxation times that was only evident in the 100-75% method. Bicarbonate ingestion resulted in higher plasma lactate but had minimal effect on markers of adenine nucleotide degradation. The rate of evoked force loss was greater when muscle glycogen stores were reduced by exercise and low CHO diet and this trend was reversed by additionally supplementing with creatine, but this was not associated with similar trends in markers of nucleotide degradation during incremental cycling. A novel finding of this study was that reducing muscle glycogen resulted in a more severe slowing of relaxation times that was reversed when combined with creatine supplementation. In this thesis the changes in the biochemical markers of ADP homeostasis (NH,) by dietary interventions were insignificant. However, the force and relaxation time responses may highlight the functional importance of maintaining ADP homeostasis. The fatigue-induced slowing of evoked relaxation times was different depending on the chosen method. Despite a smaller relative slowing during fatigue the 100-75% method appeared to be most sensitive to dietary interventions.

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24

Fernandez-Fernandez, Alicia. "An investigation of exercise behaviors and barriers to exercise among community-dwelling adults of diverse cultural groups." FIU Digital Commons, 2002. http://digitalcommons.fiu.edu/etd/3311.

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The purpose of this study was to investigate exercise habits in different cultural groups in order to provide guidelines for health promotion interventions. A 21-item survey with demographic information and standardized scale questions was completed by 140 individ ls. The two largest subgroups were Hispanics (n=101) and non-Hispanic whites (n=23). Statistical analysis indicated that (I) non-Hispanic whites reported significantly higher outs of exercise; (2) there were no significant differences in exercise frequency or barriers to exercise between the groups; (3) income and health status influenced exercise habits; and (4) lower health status scores were related to higher frequencies of barriers to exercise describing health limitations. Factors such as ethnicity , income, or health status influence exercise habits, and health promotion interventions should be tailored to these characteristics. Health behaviors, however, are ultimately unique to each individual. A careful analysis of personal needs that avoids stereotypes must be performed to obtain optimal outcomes.

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25

Bradley, Helen Elizabeth. "Glucose transporter 4 and localisation in skeletal muscle : the effect of glucose and insulin administration, acute exercise and exercise training." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/4832/.

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Glucose transporter 4 (GLUT4) in skeletal muscle plays a vital role in the maintenance of glucose homeostasis. Chapter 2 of this thesis develops an immunofluorescence microscopy method to generate novel information in human skeletal muscle on the effect of physiological stimuli on GLUT4 localisation, translocation to the plasma membrane and total protein content. Chapter 3 shows that training-induced increases in total GLUT4 protein content are driven by increases in the number of large and size of smaller intracellular GLUT4 storage clusters in human skeletal muscle. In chapter 4 the method successfully demonstrates GLUT4 translocation 30 min following glucose ingestion and 30 min after the start of moderate intensity cycling exercise in humans. GLUT4 translocation after glucose ingestion is transient and modest in comparison to the exercise response. Chapters 5 and 6 report no changes in GLUT4 translocation following an 80 min hyperinsulinaemic-isoglycaemic clamp in rats and a 2 h hyperglycaemic clamp in humans despite elevated rates of whole body glucose disposal in both experiments. This immunofluorescence method will be a valuable analytical tool in future studies investigating the mechanisms behind changes in muscle glucose uptake in response to obesity, age-related chronic diseases and therapeutic interventions including diet and exercise.

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26

Digenio, Andres G. "Effects of exercise training on left ventricular function and exercise capacity in patients with coronary artery disease and varying degrees of left ventricular dysfunction." Doctoral thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/26919.

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The medical profession has increased its acceptance of the benefits of exercise training for patients with uncomplicated coronary artery disease. Access to more modem technology and better management of this condition has led to an increase in the number of patients surviving acute coronary episodes . Some of these patients may have developed chronic asymptomatic left ventricular dysfunction and/or residual myocardial ischaemia, and could become potential candidates for cardiac rehabilitation if exercise training could induce physiological benefits without further deteriorating their condition. Over the last 10 years, several patients at moderate to high risk of future cardiovascular events because of the presence of left ventricular dysfunction and/or myocardial ischaemia have been accepted for cardiac rehabilitation at the Johannesburg Cardiac Rehabilitation Center. The purpose of the study was to evaluate the effects of exercise training on left ventricular function and exercise capacity in patients with coronary artery disease and varying degrees of left ventricular dysfunction and/or myocardial ischaemia attending the Johannesburg Cardiac Rehabilitation Center.

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27

Reynolds, Linda J. "Acute post-exercise cardiovascular responses in healthy participants." Thesis, University of Gloucestershire, 2013. http://eprints.glos.ac.uk/942/.

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The overall aim of this project was to investigate the acute cardiovascular post-exercise response in healthy individuals. The aim of the first study was to establish the within day and between day reproducibility of supine and tilt baroreflex sensitivity (BRS) utilising time (sequence) and spectral indices in 46 healthy adult males employing three repeat measures; baseline, + 60 min and + 24 h. Reproducibility was assessed by the 95% limits of agreement (LOA) to assess the extent of agreement and an alternative approach of estimating the technical error of the measurement (TEM) to assess reproducibility was also undertaken. The LOA indicated same day reproducibility was marginally better than between day reproducibility for spectral parameters while between day reproducibility was marginally better than same day reproducibility for sequence parameters with reproducibility markedly improved across all BRS outcome measures during tilt. Precision expressed by TEM for all spectral outcomes was good in both supine and tilt BRS (< 6 %) although precision was lower, but acceptable, for sequence BRS outcomes in both positions (< 11%). Thus, all BRS outcome measures and the tilt procedure were incorporated into the exercise study. The aim of the second study was to compare the response of supine and tilt BRS following a single bout of moderate intensity exercise and high intensity exercise. Further details are given in the full abstract above.

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28

MacLaren, Donald Peter Maurice. "Effects of carbohydrate intake on metabolism during exercise." Thesis, Liverpool John Moores University, 1995. http://researchonline.ljmu.ac.uk/5521/.

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29

Ussher, Michael Henry. "Randomised controlled trial of an exercise intervention for smoking cessation." Thesis, St George's, University of London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270983.

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30

Morgan, A. D. "Psychological and physiological factors affecting exercise tolerance in chronic bronchitis." Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/19158.

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31

Riley, Heather L. "Hypoxia adaptation and exercise performance at altitude." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/57196/.

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Hypoxia is defined as a deficiency in the amount of oxygen reaching the tissues, and is a common problem in critically ill patients. It is not currently possible to predict how well an individual will adapt to hypoxic conditions, and patients presenting with hypoxia are often treated with supplemental oxygen. However, this blanket-treatment approach is not suitable in all cases and a more personalised approach is required. My thesis project builds on information acquired during the Caudwell Xtreme Everest (CXE 2007) expedition, where over 200 volunteers trekked to Everest Base Camp. CXE uses studies on healthy volunteers exposed to extreme environments to aid in the understanding of the complicated issues concerned with critical illness, and aims to use these findings to improve the treatment of critically ill patients, without putting them directly at risk. My thesis project has combined physiological information acquired during CXE with biochemical information measured in plasma samples taken during CXE. Performance at altitude has been used as a proxy for hypoxia adaptation, with individuals who show a small loss of performance at altitude compared to London assumed to be adapting better compared to individuals who show a larger loss. Analysis of the physiological and biochemical data for a core group of 24 individuals has culminated in the application of multiple linear regression to produce a number of models capable of predicting the key changes in physiological response as a function of a number of biochemical metabolites. These models have been used to identify a set of biochemical metabolites to measure in a further 190 individuals, to allow validation and training of the models on a larger sample size. These models can then be adapted for use in a critical illness environment, to allow the prediction of how well an individual will adapt to hypoxic conditions.

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32

Ferrario, Chiara. "Functional electrical stimulation (FES) leg cycling exercise in paraplegia : a pilot study for the definition and assessment of exercise testing protocols and efficacy of exercise." Thesis, University of Glasgow, 2006. http://theses.gla.ac.uk/1534/.

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A custom FES-cycling ergometer equipped with an electric motor and an integrated feedback system for accurate control of exercise workrate and cadence has been employed in this study. This experimental setup allowed the imposition of arbitrary workrate profiles with high precision and provided the potential for highly-sensitive exercise testing. One aim of the work described in this thesis was to propose and evaluate novel protocols for incremental exercise test (IET) and step exercise test (SET). Valid protocols would allow reliable estimation of the key markers of cardiopulmonary fitness in SCI subjects performing FES-cycling. Measures which can be used to evaluate the effect on cycling performance of changes in stimulation parameters, and which might therefore be used to optimise them, were also investigated. Thus, a second aim of this work was to determine whether oxygen uptake and a new measure of stimulation cost (i.e. the total rate of stimulation charge applied to the stimulated muscle groups during cycling) are sensitive enough to allow discrimination between the efficacy of different activation patterns during constant-power cycling. A discussion on the concept of metabolic efficiency in AB and SCI subjects is presented in this thesis. Efficiency of FES-cycling is much lower than that of voluntary cycling. Therefore, a third aim of this work was to define new efficiency measurements that are more appropriate for the SCI population. Two volunteer subjects took part in this study and the data obtained from the tests they performed are presented as case studies. The main outcome shows feasibility of the two exercise testing protocols. Moreover, the first report of a ventilatory threshold in SCI subjects during FES-cycling has been provided here. Oxygen uptake and stimulation cost measurements both allow discrimination between the efficacy of different muscle activation patterns. However, stimulation cost is more easily determined in real time, and responds more rapidly and with greatly improved signal-to-noise properties than oxygen uptake.

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33

Tam, Nicholas. "The maintenance of Body Fluid Homestasis during exercise when drinking ad Libitum." Master's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/2769.

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The prescription of an optimal fluid intake during exercise has been a controversial subject in sports science over the past decade. Only recently has it evolved from 'blanket' prescriptions to more individualised recommendations. Currently the American College of Sports Medicine (ACSM) advise that sufficient fluid should be drunk in order to ensure that body mass (BM) loss does not exceed >2% of starting BM in order to avoid exercise-associated medical complications. Historically BM changes have been used as a surrogate for fluid loss during exercise. It would be helpful to accurately determine fluid shifts in the body in order to provide physiologically appropriate fluid intake advice. The measurement of total body water (TBW) via deuterium oxide has been found to be the most accurate measure to detect changes in body fluid content. Thus the aim of this thesis was to understand body fluid homeostasis during exercise when drinking according to the dictates of thirst (ad libitum). This thesis begins with a review of the literature examining the basis for fluid intake prescription with the use of BM, the concepts of 'voluntary and involuntary dehydration' and the major routes by which the body is potentially able to gain and lose fluid during exercise. We initially found that changes in TBW are more variable than BM at rest, although technical machine error accounted for a majority of the total error in the TBW measurement. Interestingly BM remains very stable at rest compared to the dynamic nature of changes in TBW both daily and weekly. We also found that measurements of both BM and TBW produce reproducible results at rest. Our first finding was that with the adoption of an ad libitum fluid intake during exercise athletes participating in the study were able to finish races of varying distances without any medical complication along with a >2% BM loss. Which leads onto our second and more important finding that we have also demonstrated that despite a >2% BM loss, all of our subjects finished their respective races whilst maintaining plasma sodium concentration ([Na+]) and plasma osmolality (POsm) within the normal range when drinking ad libitum. This finding demonstrates the reality of drinking in athletes competing in various types of foot races and that it is unnecessary to drink to maintain BM in order to successfully complete races of any distance Thirdly and most pertinent finding was that associated with this >2% BM loss we measured TBW changes during these races and found that changes in BM do not track changes in TBW during real-life competition in athletes when drinking ad libitum. This finding illustrates that to some extent, sweat losses during exercise are offset by internal water sources associated with metabolic water formation and water associated with glycogen storage ensuring the maintenance of body fluid homeostasis. It was also noted that athletes performing the best often experience the greatest BM loss during the 21.1km and we found a similar trend in the 56km race. We have suggested that this can be explained by both behavioural and physiological reasons. Lastly all athletes successfully completed their respective races without encountering any exercise-associated medical complications with the adoption of an ad libitum fluid intake approach. The outcomes from this thesis support the prescription of more physiologically appropriate advice for fluid intake prescription during exercise. We hope that these studies will provide adequate corroboration that during exercise together with an ad libitum approach, athletes are able to maintain adequate hydration (maintenance of POsm and plasma [Na+]) regardless of significant decreases in BM, which is often associated with superior performance in some athletes.

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Hughes, Adrienne Rachel. "Effect of an exercise consultation on maintenance of physical activity after completion of phase III exercise-based cardiac rehabilitation." Thesis, University of Glasgow, 2003. http://theses.gla.ac.uk/2526/.

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Aims: The primary aim of this randomised-controlled trial was to evaluate the effect of an exercise consultation (experimental condition) compared with standard exercise information (control condition) on maintenance of physical activity six and 12 months following completion of a phase III hospital-based exercise programme. Secondary aims included assessing the effect of an exercise consultation compared with exercise information on physiological and psychological variables at six and 12 months. Conclusions: This study demonstrated that the exercise consultation was more effective than exercise information in maintaining self-reported physical activity for 12 months after completion of a phase III exercise programme. However, the change in CSA accelerometer readings over the 12-month study period did not parallel the significant decrease in self-reported physical activity observed in the control group. The exercise consultation was not effective in maintaining exercise capacity for 12 months after completion of phase III. Significant decreases in peak VO2 from baseline to 12 months were observed in both groups. In contrast, an improvement in the VO2 at the lactate threshold, which is an index of submaximal endurance capacity, was recorded in the experimental group compared to the control group from baseline to follow-up. Finally, the exercise consultation had no significant effect on processes of exercise behaviour change, lipid profile and psychological function. These variables were normal at baseline and were maintained over the study period in both groups. The results of this study demonstrate that the exercise consultation may be an effective intervention for maintaining physical activity after completion of phase III hospital-based exercise programmes. The exercise consultation is a minimal intervention that could be delivered by physiotherapists to patients at the end of phase III or by British Association of Cardiac Rehabilitation (BACR) trained exercise instructors to patients in phase IV.

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Barakat, Hashem M. "Preoperative supervised exercise and outcomes following elective abdominal aortic aneurysm repair." Thesis, University of Hull, 2014. http://hydra.hull.ac.uk/resources/hull:11175.

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Objective: The aim of this research was to evaluate the role of preoperative supervised exercise training on perioperative outcomes and cardiopulmonary exercise testing (CPET) parameters in patients undergoing elective abdominal aortic aneurysm (AAA) repair, and to analyse the value of different preoperative risk assessment tools in predicting postoperative complications following this intervention. Methods: Participants in this project were patients with large AAA (≥ 5.5 cm), awaiting elective open or endovascular repair. Study 1: was a prospective randomised controlled trial. Participants were randomised in two parallel groups: a 6-week preoperative exercise training programme or standard treatment. The primary outcome measure was the composite endpoint of postoperative cardiac, pulmonary and renal complications. Secondary outcome measures were: lengths of hospital and critical care stay, APACHE II scores recorded within 6 hours postoperatively, SIRS criteria, thirty-day mortality, reoperation and postoperative bleeding. Patients were followed up for 3 months postoperatively. Study 2: was a sub-group study within Study 1. A sub-group of patients from Study 1 consented to undergo two rather than one preoperative CPETs: the first at baseline, and a second following completion of 6 weeks of exercise or on the day immediately prior to surgery. The primary outcome measure was the effect of exercise on CPET parameters. Study 3 utilised univariate and multivariate analysis to assess the value of different preoperative risk assessment tools in predicting postoperative complications in patients undergoing elective AAA repair. Results: Study 1: 136 patients were recruited, 12 withdrew before operative interventions and were not included in the analysis. A total of 124 patients (62 in each group) were included (111 men, mean (s.d.) age 73 (7) years), of which 46 patients underwent EVAR (23 in each group). 14 patients (22.6 per cent) sustained postoperative complications in the exercise group, compared to 26 (41.9 per cent) in the non-exercise group (P=0.021). Four patients (3.2 per cent; 2 in each group) died within 30 days postoperatively. Length of hospital stay was significantly shorter in the exercise group (median (IQR) 7 (5-9) days) than the control group (median (IQR) 8 (6.0 - 12.3) days) (P=0.025). There were no significant differences in the length of critical care stay (P=0.845), APACHE II scores (P=0.256), incidence of re-operations (P=1.000) or postoperative bleeding (P=0.343) between the two study groups. Study 2: 48 patients were recruited: 33 patients in the exercise group, and 15 in the control group. All participants completed their two CPET assessments. A 6-week exercise schedule improved aerobic fitness parameters compared to the control group. Median (IQR) VO2 peak improved from 18.4 (15.0-20.9) to 20.0 (16.9-21.3) ml O2/kg/min; P=0.004, and median AT improved from 12.0 (10.4-14.5) to 13.9 (10.6-15.1) ml O2/kg/min; P=0.012. There were no statistically significant changes in CPET parameters in the control group. Study 3: In 124 patients undergoing elective AAA repair, lower AT (OR 0.59, 9% C.I. 0.38 to 0.89, p=0.014) and higher V-POSSUM scores (OR 1.42, 95% C.I. 1.16 to 1.75, p=0.001) were the only independent predictors of postoperative complications. A low AT was an independent predictor of cardiac complications (OR 0.59, 95% C.I. 0.36 to 0.96, p=0.034) and a high VE/VCO2 predicted pulmonary complications (OR 1.24, 95% C.I. 1.03 to 1.51, p=0.027). Conclusion: Preoperative supervised exercise training appears to reduce postoperative complications and length of hospital stay in patients undergoing elective AAA repair. The mechanism appears to be an improvement in aerobic fitness preoperatively. CPET is a valuable preoperative assessment tool for elective AAA patients as it predicts organ-specific complications and may be useful in directing perioperative care.

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Steiner, Michael Charles. "The nutritional enhancement of exercise training in chronic obstructive pulmonary disease." Thesis, University of Leicester, 2003. http://hdl.handle.net/2381/29444.

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Learmonth, Yvonne Charlotte. "Therapeutic exercise for those moderately affected with Multiple Sclerosis." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3595/.

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Multiple Sclerosis (MS) is a chronic progressive disease which presents with a variety of cognitive, motor and sensory deficits. Rehabilitation strategies to help manage some of these deficits include increasing physical activity and undertaking therapeutic exercise. A literature review begins this thesis and where relevant gaps are highlighted. These include; minimal literature on the long-term effects of therapeutic exercise, the views of those with MS taking part in therapeutic exercise and the characteristics of outcome measures used to assess those with MS. To address these areas three studies are presented related to therapeutic exercise for those moderately affected with MS (defined as an Expanded Disability Status Score of 5 to 6.5). In the first study, a 12-week therapeutic exercise programme was delivered to twenty people with MS, whilst 12 people acted as controls who received usual care. Clinical outcomes were assessed at five time points over the intervention and 12-month follow-up period of the study. No statistically significant results emerged to suggest the intervention was effective, however calculated effect sizes indicated the intervention had a positive effect on areas related to the physiological (strength, mobility, fatigue and body composition), functional (mobility, balance and activity participation) and psychological (mood and quality of life) status of participants. The second study sought to establish the views and opinions of participants, who had attended the exercise intervention. Three inter-related themes emerged. These were (1) the Exercise Class, which developed as a bridge to allow participants to realise (2) the Benefits of the Class, helping them to overcome (3) Barriers to Exercise. Results suggested the benefits to participating in exercise and the exercise intervention included social support and symptom improvement. Barriers to exercise included perceived psychosocial factors, symptoms and lack of service. A third study investigated the test re-test reliability of four outcome measures used in the first study, calculations were done to establish the clinically significant change and precision of the outcome measures. The test re-test reliability of the outcome measures was good, with the calculated clinical change and precision of the outcome measures in those moderately affected with MS highlighting the problems of assessing those with MS. The overall investigation suggests that therapeutic exercise and monitoring its effect in MS is good. Clinical and research recommendations emerged from this work, these include that the heterogeneity of symptoms presented in MS should be considered in future research designs and that group therapeutic exercise may improve physiological, functional and psychological status of those with MS, with the social benefits important to participants.

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Chantler, Paul David. "Age-and-exercise-related effects on cardiac power output." Thesis, Liverpool John Moores University, 2004. http://researchonline.ljmu.ac.uk/5640/.

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Ageing is an inevitable process characterised by a progressive deterioration in the function of a number of organs and systems, ultimately reducing the individual's quality of life. Despite its obvious importance, our understanding of the basic age-related changes in cardiac function remains poor. In part because past studies, describing the changes in cardiac function with age, have not always adequately controlled for different lifestyles or superimposed diseases, while using less than complete measures of overall cardiac function and appropriate scaling models. The aim of this thesis was to determine the changes in overall cardiac function associated with healthy ageing, using the comprehensive, non-invasive method of cardiac power output (CPO). After identifying that CPO was not affected by circadian rhythms, 149 sedentary men and women (19-75 years) and 60 active men were investigated. All were free from cardiovascular diseases and medications. The findings indicated that healthy ageing, in all subject populations, was associated with an ~17% decline in CPOrest, ~15% in CPOmax, and ~14% in CR. Age for age, sedentary men had greater CPO values than women, both at rest (~19%) and at maximal exercise (~25%). In addition, cardiac function was greater in the active men, compared with age-matched, sedentary controls, with values ranging from 11-30% greater. It was also found that body composition had a significant impact on the interpretation of CPO data. For example, when scaled allometrically for fat free mass (FFMb), absolute sex-related differences in CPO disappeared, as did the age-related decline in CPOrest. Also, in women no age-related changes in CPOmax were found once normalised to FFMb even though in men, CPOmax and CR still declined with age. Clearly, how these data are normalised relative to body composition is crucial to the interpretation of the effects of ageing or an active lifestyle. These are novel findings and indicate that healthy ageing is associated with reductions in overall cardiac function, as represented by significant declines in CPOmax and CR in men, but not women. In addition, endurance training improved aerobic capacity while attenuating the changes in cardiac function.

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Barwell, Nicholas Dominic. "Studies of the interaction between diabetes family history, exercise, adiposity and metabolic health." Thesis, University of Glasgow, 2010. http://theses.gla.ac.uk/2072/.

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The rising tide of obesity and type 2 diabetes has been recognised to have reached epidemic proportions. There is a significant burden of mortality and morbidity associated with the development of these conditions and current estimates suggest that the burden of disease in the next two decades is likely to place considerable strain upon healthcare systems, particularly in the developing world. The development of insulin resistance is a key contributor to the pathogenesis of type 2 diabetes, however the origin of insulin resistance is complex and it is currently unclear precisely how the inter-related components of this metabolic dysfunction are triggered. Obesity is also implicated in the pathogenesis of insulin resistance and represents a risk factor which is potentially modifiable by lifestyle interventions such as exercise and weight loss. Observational and prospective studies have also shown the benefits of lifestyle intervention in reducing the incidence of diabetes in those judged to be at greater risk. People with a parental history of type 2 diabetes have an increased lifetime risk of diabetes and frequently display metabolic abnormalities which, despite persisting normoglycaemia, are evidence of a ‘pre-diabetic’ state and which may themselves carry increased morbidity and mortality. Observational studies suggest a greater difference in insulin sensitivity between active and sedentary offspring, compared to the difference between active and sedentary individuals with no diabetes family history. This is thought to represent an interaction between positive energy balance, a sedentary lifestyle and a ‘thrifty genotype’. These observations suggest that individuals with a parental history of diabetes are more susceptible to the deleterious health effects of a sedentary lifestyle, but that they may be more responsive to an increase in physical activity. Exercise interventions can be expected to have positive effects upon metabolic health and adiposity however, the individual response to exercise is extremely variable. Other factors such as lifestyle alteration have been implicated in the difference between the observed and predicted response to exercise. Therefore, the aim of this thesis was to examine the physical, metabolic and lifestyle differences between sedentary pre-menopausal women with a parent with type 2 diabetes and matched control subjects with no family history of the condition. In particular, this thesis aimed to explore the effect of an aerobic exercise intervention on metabolic health and body composition, whether the response to exercise is dependent upon a familial history of diabetes and the processes by which exercise might induce any observed changes. In order to explore the impact of a sedentary lifestyle on women with, and without a family history of type 2 diabetes, thirty four pre-menopausal, sedentary women with a parental history of diabetes (Offspring) and thirty six matched women without a familial history of diabetes (Controls) were recruited. Assessments of body composition, insulin sensitivity, adipose tissue-derived hormone concentration, substrate utilisation, endothelial function by carotid-radial pulse wave velocity, cardiorespiratory fitness, diet and habitual physical activity were performed. Twenty eight Offspring subjects and thirty four matched Controls participated in a seven-week aerobic exercise intervention, training at 65-80 % of predicted maximal heart rate with incremental increases in training duration on a weekly basis. The previously described assessments were performed before and 15-24 hours after the intervention and in a subgroup of 19 Controls and 17 Offspring subjects, further assessments of insulin sensitivity, adipose tissue-derived hormone concentration, substrate utilisation and endothelial function were performed after a further three day period without exercise. In order to determine potential mediators of exercise-induced fat loss fifty five women participated in measurements of substrate utilisation, body composition, endothelial function, insulin sensitivity, cardiorespiratory fitness, dietary intake and habitual physical activity prior to, and after the seven week exercise intervention. The findings from these studies confirmed that sedentary women with a family history of type 2 diabetes displayed lower insulin sensitivity than those without a parental history of diabetes. In addition, insulin resistance in this group appears to be related to a greater sensitivity to the influence of adipose tissue, particularly circulating non-esterified fatty acids and adipose tissue-derived inflammatory cytokines. In Offspring alone, baseline insulin sensitivity was associated with plasma adiponectin concentration and negatively associated with circulating non-esterified fatty acid concentration. These associations may represent physiological attempts to compensate for developing insulin resistance. Offspring also displayed an augmented metabolic response to the exercise intervention in comparison to Controls. This study showed a 23% increase in post-intervention insulin sensitivity in Offspring with no significant increase in insulin sensitivity in Controls despite a similar improvement in cardiorespiratory fitness and adherence to the exercise regime. Improved post-intervention insulin sensitivity was accompanied by reduced circulating leptin, increased fat and decreased carbohydrate oxidation in both fasting and post-glucose states. No change in diet was observed but Offspring appeared to increase their level of habitual physical activity. The magnitude of change in insulin sensitivity was associated with a parental history of diabetes, but stronger associations were observed between baseline insulin resistance and an ability to reduce circulating leptin in response to exercise. Wide individual variation in fat mass change was observed in the response to exercise, and as expected the strongest predictor of exercise-mediated fat mass reduction was the net energy cost of the intervention. However, a change in fasting respiratory exchange ratio (RER), suggesting an increase in fat oxidation was also independently associated with reduced fat mass. The combined findings of this thesis suggest that sedentary pre-menopausal daughters of people with type 2 diabetes are more insulin resistant and that this state is, in part, a consequence of heightened sensitivity to fatty acid and inflammatory cytokine release from adipose tissue. However, it would also appear that they represent a high-risk group who are susceptible to the insulin-sensitising effects of exercise and that this may be mediated by a metabolic pathway which involves reductions in circulating leptin concentrations. Finally, the ability to lose fat mass in response to exercise is related to the energy deficit incurred by the activity but also by an individual’s ability to shift fasting substrate utilisation towards fat oxidation. Public health strategies have traditionally focused upon lifestyle interventions which are directed at the population in general. However, awareness of the risks conferred by obesity and familial history of type 2 diabetes and the potential benefits of intervention may suggest that targeting public health resources towards these high-risk groups is a more appropriate and effective strategy.

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Kerr, Morag Graham. "Biochemical and physiological aspects of endurance exercise in the horse." Thesis, University of Glasgow, 1985. http://theses.gla.ac.uk/3993/.

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A number of biochemical and haematological changes are known to occur in horses involved in long distance riding competitions of 40- 160 km, particularly changes associated with disturbances in fluid/ electrolyte balance, catabolism of body fuel stores and alterations in the integrity of the muscle cell membrane. This study investigated these changes in more detail in 50 horses involved in competitive rides and in four horses undergoing two 80 km rides under controlled conditions. In addition, experiments were carried out on horses and ponies exposed to a hot, humid environment (41°C, 33°C wet bulb) and during intravenous adrenaline infusion, in order to study further the fluid/ electrolyte alterations associated with sweating and in particular the composition of equine sweat. Changes in plasma and urine biochemistry were also studied over 24 hours in horses at rest for comparative purposes. Significant changes were shown in 13 of the 14 plasma parameters measured in the resting horses. Most of these could be related to feeding, in particular to hay feeding which caused alterations in fluid/ electrolyte balance associated with salivary secretion. Urine composition changed very markedly during the 24 hours. Urine flow rate and creatinine and urea excretion were higher during the day and increased following drinking, as in man. Urine potassium and chloride excretion were much higher than sodium excretion and all three electrolytes (and pH, which was alkaline) showed diurnal variations markedly different from those in man. The competing endurance horses demonstrated moderate haemoconcentration, but plasma electrolyte alterations, particularly an increase in sodium concentration, were not always consistent with the production of apparently hypertonic sweat. The pattern of fuel utilisation was one of exhaustion of liver glycogen after about 40 km with extensive fat mobilisation and the use of glycerol for gluconeogenesis. Breakdown of phosphocreatine was extensive and evidence of protein catabolism was observed. Large variable increases in plasma CK and AST activities unassociated with fatigue suggested a non-pathological alteration in muscle cell membrane integrity in a number of horses. During heat exposure changes in PCV and plasma proteins were poorly related to fluid losses but changes in electrolyte concentrations were consistent with the sweat tonicity. Hypertonic chloride and potassium, and isotonic sodium concentrations (relative to plasma) were maintained in the sweat for 4.5 hours. In contrast sweat magnesium and protein concentrations were initially high but decreased exponentially with time. There was a very close correlation between these two parameters. Most of the changes in plasma parameters seen during adrenaline infusion were attributable to the adrenaline per se, but the profuse sweating induced in the horses caused some haemoconcentration. Small ponies sweated much less in response to adrenaline than Thoroughbred horses. Hypertonic sweat concentrations of chloride, sodium and potassium were maintained for 3 hours and significant differences, particularly in Na/K ratio, were found between heat and adrenalineinduced sweat. Sweat urea concentration was related to plasma urea concentration and glucose appeared in the sweat when the plasma glucose concentration exceeded 10 - 12 mmol/l. The sweat magnesium was not protein-bound and the two main electrophoretic fractions of the sweat protein were not present in serum. The possible function of this protein as a wetting agent was discussed. During the controlled 80 km rides total fluid loss was 33.5% of the total ECF volume: 78% of this was sweat and 22% respiratory evaporation. Although sweat electrolyte concentrations were again hypertonic to plasma, theoretical concentrations in total body (sweat plus respiratory) water loss were much closer to plasma concentrations - slightly hypotonic for sodium, slightly hypertonic for chloride. As a result changes in plasma electrolyte concentrations were small, an increase of 9 mmol/1 (5.7%) in sodium and a decrease of 4 mmol/l (3.5%) in chloride. Potassium appeared to move out of the intracellular fluid at the start of exercise and back in immediately afterwards and this obscured any effect of sweat losses on plasma concentration. The only urinary constituent which was conserved in the exercising horses was chloride, and the absence of any decrease in urea excretion suggested that the increase in plasma urea concentration was due to increased protein catabolism, probably from the liver. Body fuel utilisation was similar to that seen in the competing horses and plasma CK and AST activities again suggested that a non-pathological disruption of muscle cell membrane integrity was occurring in some horses which continued intermittently for several months. It was concluded that in the horse, unlike man, the thermoregulatory fluid is approximately isotonic to plasma, which minimises electrolyte imbalances and allows prolonged exercise with less need for drinking. After exercise the large caecum and colon and the sodium contained in them appear to be important in the controlled replacement of the extensive water and electrolyte losses which result.

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Chua, Tuan Peng. "Chronic heart failure and factors contributing to the increased ventilatory response to exercise." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363087.

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42

Pitsiladis, Yannis P. "Diet manipulation, altered fat and carbohydrate metabolism and exercise performance in trained humans." Thesis, University of Aberdeen, 1996. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU089995.

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The aim of the first two experiments was to determine whether alterations in dietary carbohydrate (CHO) intake would affect performance of high intensity exercise in well-trained individuals. This was achieved by comparing the effects of a 70 and 40% CHO diet on the performance of high intensity exercise lasting approximately 10 min (Experiment 1) or 30 min (Experiment 2). At both exercise intensities, no difference in exercise performance was found. These results demonstrated that moderate changes in diet composition during normal training do not significantly affect performance of high intensity exercise in well-trained individuals. These findings would suggest that total muscle glycogen concentration was not limiting high intensity exercise performance. The higher than normal daily energy intake of the subjects' diet may have adequately compensated for the reduced percentage of CHO on the two low CHO diets. An increased fat oxidation on the low CHO trial may also have contributed to these results. These results do not exclude the possibility that the glycogen content of individual muscle fibres was limiting high intensity exercise performance. The aim of the third experiment was to determine the effects of an exercise and diet regime, which was intended to alter initial muscle glycogen concentration, on the capacity of well-trained individuals to perform prolonged strenuous exercise to exhaustion in the heat and the cold. Exercise capacity in the heat was reduced compared with exercise in the cold, irrespective of diet. The exercise and diet intervention, when aimed at increasing muscle CHO stores, improved exercise capacity both in the heat and in the cold compared with when the intervention was aimed to reducing CHO stores.

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Bridge, Matthew Wakefield. "Mechanisms of fatigue during prolonged exercise in the heat." Thesis, University of Birmingham, 2002. http://etheses.bham.ac.uk//id/eprint/471/.

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Increase in body temperature is a major factor limiting endurance performance in the heat and it is shown in this thesis that the effects of raised body temperature on performance, perception and neuroendocrine response to exercise are mediated by an interaction of body temperatures. Prolactin has been used as an indicator of hypothalamic activity and the pathways regulating its release have been investigated using pindolol as a 5-HT$_ $ antagonist. The prolactin response to a buspirone challenge has been shown to be approximately 50% serotonergic and 50% dopaminergic, but with a wide inter-subject variation. Passive heating is a potent stimulus for prolactin release and it was shown that 5-HT$_ $ stimulation plays virtually no part in this process, raising the possibility that prolactin release during hyperthermic exercise may also be largely due to withdrawal of dopamine inhibition. A comparison of exercise tolerance in the heat and the sensitivity of central serotonergic and dopaminergic pathways further indicates the importance of dopamine in central fatigue. The action of caffeine in enhancing endurance performance has been shown not to involve the hypothalamus and this draws attention to other pathways that may be involved in central fatigue including the basal ganglia and limbic system.

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Ghafouri, Khloud Jamil. "Effect of exercise, diet and ethnicity on metabolic responses in postprandial state." Thesis, University of Glasgow, 2018. http://theses.gla.ac.uk/8634/.

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Cardiovascular disease is a leading cause of mortality and morbidity worldwide. One of the key factors mediating cardiovascular disease risk, and the underlying atherogenic disease process, is disturbances to metabolism in the postprandial state, particularly with respect to lipoprotein metabolism. A number of studies have demonstrated that prior exercise can reduce postprandial triglyceride (TG) concentrations, with recent evidence indicating that increased clearance from the circulation of large very low density lipoproteins (VLDL1) plays an important role. However, it was unclear how exercise facilitated this potentially beneficial effect and this was the focus of the present work. The first experimental study in this thesis demonstrated, in 10 overweight/obese men, that 90 minutes of prior moderate exercise increased the affinity of VLDL1 for TG hydrolysis by lipoprotein lipase by 2.2-fold in the fasted state (p = 0.02) and 2.6-fold in the postprandial state (p = 0.001), but did not significantly alter the affinity of chylomicrons, a novel observation that adds to understanding of the mechanism by which exercise lowers TG concentrations. Postprandial responses to meal ingestion depend on the macronutrient composition of the food ingested. In the second experimental chapter, postprandial responses to ingestion of a test meal containing 75g glucose, or 75g fat, or a combination of 75g glucose and 75g fat were compared in 10 overweight/obese men. The main finding was that co-ingestion of fat with the glucose load reduced the postprandial glucose response, but not insulin response, compared with glucose ingestion alone. Co-ingestion of fat with the glucose load also substantially reduced the postprandial suppression of non-esterified fatty acids (NEFA) compared to glucose only ingestion. Postprandial TG responses were similar when only fat was consumed compared with co-ingestion of fat and glucose, but postprandial VLDL1 concentrations were lower in the latter condition. It is well established that ethnic differences exist in the prevalence of cardio-metabolic diseases. In particular, diabetes prevalence is high in Middle-Eastern populations. It is not known whether ethnic differences in postprandial metabolism contribute to these differences in risk. In the third experimental study, eight white European men and eight men of Middle-Eastern origin consumed a mixed-meal and postprandial responses were assessed. Postprandial insulin responses were higher in the Middle-Eastern men and postprandial TG concentrations were higher in the European men. This suggests that ethnic differences may exist in the inter-relationship between insulin resistance and lipoprotein metabolism. Thus, overall this thesis has provided insights into how postprandial metabolism is modulated by exercise, macronutrient intake and ethnicity.

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Richardson, Katharine. "The effect of preoperative exercise and training on postoperative outcome." Thesis, University of Kent, 2015. https://kar.kent.ac.uk/50849/.

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The overall aim of this thesis was to investigate the effect of preoperative exercise and training on postoperative outcome. Poor cardiorespiratory fitness has been associated with poor postoperative outcome including increased length of hospital stay and postoperative complications. Thus, increasing cardiorespiratory capacity prior to surgery via preoperative exercise training could potentially alter postoperative outcome. High intensity exercise training (HIIT) has been demonstrated to be an efficient training intervention to increase cardiorespiratory capacity in as little as 2 weeks. It was hypothesised that chronic preoperative exercise training (i.e. 2 weeks HIIT) would improve postoperative outcome measures (i.e. length of stay, complications and mortality) in urology cancer resection patients in comparison to a usual-care-only group (UC). Thirty-five urology cancer resection patients voluntarily enrolled into the study, of these thirty completed the study (15 UC, 15 EXP). There was a significant increase in length of stay (LOS) in the EXP group in comparison to the UC group (4.0 ±6.0 versus 3.0 ±1.5 days, P=0.03), respectively. However, after accounting for covariates (surgical severity, number of operations) LOS was not significantly different between groups (5.8 ±0.8 versus 5.0 ±0.8 days; P=0.24) for UC and EXP patients, respectively). There were no significant differences between groups for postoperative complications on days 1-8 post-surgery (P>0.05), despite significant differences between groups for VO2peak change data (-2.2 ±0.8 ml.kg-1.min-1 versus +1.3 ±0.8ml.kg-1.min-1; Eta2:0.24; P=0.02) for UC and EXP patients). Overall, two weeks preoperative HIIT does not appear to alter postoperative outcome in urology cancer resection patients. The effect of two weeks preoperative HIIT was investigated in colorectal cancer resection patients. It was hypothesised that chronic preoperative exercise training (i.e. 2 weeks HIIT) would improve postoperative outcome measures (i.e. LOS, complications and mortality) in colorectal cancer resection patients in comparison to the UC group. Twenty-one colorectal patients voluntarily enrolled into the study and completed the study (12 UC, 9 EXP). There were no significant differences between groups for LOS, (7.0 ±8.5 versus 6.0 ±2.0 days, Eta2:0.04; P=0.38) for UC and EXP patients, respectively). The Cox Regression hazard ratio was 1.55, suggesting that there was a 55% increased likelihood of being discharged on any given postoperative time point in the EXP group when compared to the UC group (95% CI: 0.25 to 1.65; P=0.36). There were no significant differences between groups for postoperative complications for days 1-10 post-surgery (P>0.05). Though, there was a moderate to large effect size for a reduction in postoperative complications on the 2nd (Eta2: 0.09), 4th and 8th postoperative day (Eta2: 0.07), in favour of the EXP group. There were no significant differences between groups for cardiorespiratory measures (i.e. AT, VO2peak) (P0.05). Thus, 2 hours hypoxia (O2: 14.5%) did not appear to significantly alter salivary stress markers. Therefore, the role of the cross-stressor adaptation hypothesis in exercise induced cardioprotection is unclear. The overall conclusion of this thesis is that preoperative exercise appears to improve postoperative outcome measures in AAA patients. However, the benefits of preoperative exercise training on postoperative outcome in colorectal and urology patients is equivocal. Though, there was a group effect on postoperative complications on days 2, 4 and 8 post-surgery in colorectal patients, in favour of the EXP group. Lastly, an acute bout of exercise did not appear to attenuate the stress response to a subsequent stressor.

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Hodgson, Adrian. "Influence of nutritional interventions to optimise fat metabolism and exercise performance." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4676/.

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This thesis investigated three commonly used nutritional interventions that are often claimed to alter substrate metabolism and improve exercise performance: green tea extract (GTE), coffee and vitamin D. GTE and caffeine have been hypothesized to increase fat oxidation at rest and during exercise, thereby lowering the reliance on skeletal muscle glycogen and improving endurance exercise capacity. We observed that 7 days GTE supplementation resulted in an increase in metabolites related to fat and energy metabolism at rest but not during moderate intensity exercise. The current thesis also found that endurance exercise performance can be improved to the same extent by either using coffee or caffeine. However, these improvements in endurance exercise performance were independent of changes to fat oxidation during exercise. We also demonstrate that athletes living in Birmingham, United Kingdom, display a high prevalence of vitamin D deficiency during the winter and thus require nutritional support. However, despite the high prevalence of vitamin D deficiency, there was no association between vitamin D status and skeletal muscle function or exercise performance. Short term vitamin D supplementation at doses above the current recommended daily allowance was highly effective in correcting vitamin D deficiency to sufficiency. But supplementation did not alter any measure of performance.

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Clarke, Neil David. "Strategies for optimal hydration and energy provision for soccer-specific exercise." Thesis, Liverpool John Moores University, 2006. http://researchonline.ljmu.ac.uk/5787/.

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Sari-Sarraf, Vahid. "The effects of soccer-specific intermittent exercise on salivary IgA responses." Thesis, Liverpool John Moores University, 2006. http://researchonline.ljmu.ac.uk/5817/.

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Exercise has been demonstrated to influence susceptibility to upper respiratory tract infections (URTI) because various aspects of immune function including mucosal immunity are temporarily changed after exercise. Lower concentrations of salivary 19A (s-IgA) as a predominant immunoglobulin and component of saliva or a chronic deficiency in s-IgA have been associated with an increased frequency of URTI episodes. Previous studies of aerobic exercise have incorporated the performance of running or cycling. Responses of s-19A to intermittent exercise patterns as they occur in soccer remain to be resolved. A laboratory based soccerspecific intermittent exercise protocol was used within this thesis to mimic the physiological stress associated with soccer, characterised by highintensity activity as noted during soccer play. The aims of this thesis were to determine the s-IgA responses to a bout or repeated bouts of soccerspecific intermittent exercise and investigate the effects of carbohydrate ingestion on s-IgA when such exercise is performed in increased ambient temperature. Laboratory based soccer-specific intermittent exercise and continuous exercise at the same moderate exercise intensity evoked insufficient stimulation of the hypothalamic-pituitary-adrenal axis to modify s-IgA responses. Changes in s-19A and cortisol did not differ between exercise types during or immediately following exercise, or 6 h, 24 h and 48 h afterwards. Physiological responses to intermittent exercise also conforming to the activity pattern of soccer match-play were similar to those for continuous exercise at the same average work-rate, despite the higher perceived exertion during intermittent exercise. Two bouts of soccer-specific intermittent exercise 48 h apart that were designed to provide a repeatable physiological stress comparable to strenuous soccer training induced s-19A responses that were similar following both bouts of exercise. Performing the second bout of exercise did not significantly suppress s-IgA concentration after 48 h recovery although a small progressive reduction in s-19A was observed. Performance of a second soccer-specific exercise bout in one day with a 2.25 h rest in between bouts elicited an increase in heart rate and perceived exertion, compared with a single session at the same time of day, but did not appear to suppress s-IgA outcomes. There was also no difference between responses of s-IgA concentration and secretion rate or salivary cortisol at the different times of day. Soccer can be played under hot environmental conditions and it is thought that addition of carbohydrate to fluids may prevent adverse changes in mucosal immune responses. Carbohydrate supplementation before and at regular intervals whilst performing soccer-specific intermittent exercise at 30°C, did not influence s-IgA responses or salivary cortisol when compared to placebo. In view of the failure of these experimental interventions to discern effects on s-IgA responses, a meta-analysis of the literature was conducted. The meta-analysis revealed an overall elevation in s-IgA concentration post acute exercise and following chronic exercise. In contrast, in term of s-IgA secretion rate, an overall significant decline after both acute and chronic exercise was a consistent finding. In conclusion, one exercise bout or repeated soccer-specific intermittent exercise in the present experiments did not induce compromises in s-IgA responses. There was no adverse effect upon s-IgA responses to intermittent exercise performance under conditions of heat stress with or without carbohydrate treatment. Although, 32 percent of studies included in the meta-analysis have indicated similar results, the disparity with overall findings may arise from differences in the exercise protocols used and/or bias for s-IgA changes in published studies.

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Mist, Bryan A. "The acute and chronic effects of exercise in renal patients undergoing regular dialysis therapy." Thesis, University of Salford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241573.

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Bruce, Richard. "The role of skeletal muscle afferent feedback in ventilator and cardiovascular control during human exercise." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/4819/.

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Abstract:

Stimulating muscle metaboreceptive afferents alone via post exercise circulatory occlusion (PECO) typically does not result in hyperpnea in healthy humans. However ventilatory responses have been observed if metabolite accumulation is great enough (e.g. in diseased states) or during a concurrent hypercapnia-induced chemoreflex, suggesting a possible synergistic interaction. This thesis investigated the ventilatory responses to interactions between muscle afferent feedback and potentially synergistic inputs. It was firstly observed that muscle metabo/mechanoreflex activation (via PECO and passive muscle stretch, respectively) increases ventilation but only during acute hypercapnia. Additional investigations suggested that these ventilatory responses were caused by a central interaction, possibly between the medullary input from muscle afferents and central chemoreceptors. Secondly, experimental augmentation of the muscle metaboreflex enhances the ventilatory response during exercise, but not during PECO, suggesting interactions between the metaboreflex and other inputs activated in exercise. Lastly, PECO caused increased ventilation in COPD patients but this was unrelated to chronic hypercapnia. Collectively these findings suggest that in health, muscle metabo/mechanoreflex stimulation induces ventilatory responses, but their effects only appear to be unmasked in combination with secondary synergistic inputs. However, when the metaboreflex is powerful enough, arguably such as in COPD, ventilatory responses to metaboreceptor stimulation alone can be observed.

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Dissertations / Theses on the topic 'Exercise medicine'

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