Description:
Cancer is a prevalent disease with significant morbidity and mortality rates. Exercise interventions implemented before, during, or after cancer-based surgeries have shown promising benefits in improving fitness, postoperative complications, and quality of life. This thesis comprises three original research chapters aimed at investigating the effect of perioperative and preoperative 'prehabilitation' exercise in breast, colorectal, and prostate cancer patients. The first study focused on exploring exercise therapy interventions and their impact on cardio-respiratory fitness and 30-day postoperative outcomes in colorectal cancer patients. The systematic review and meta-analysis (N= 411 intervention and N= 368 control) revealed a small but significant improvement in cardio-respiratory fitness (SMD = 0.18; 95% CI = 0.03, 0.32; p < 0.05) with exercise interventions, although no significant impact on 30-day postoperative outcomes was observed. In the second study, various exercise types, including aerobic, resistance, flexibility, and mind-body exercises (alone or in combination), were compared in terms of their effect on cardio-respiratory fitness and 30-day postoperative outcomes in colorectal cancer patients (N= 411 intervention and N= 368 control). The network meta-analysis findings indicated that engaging in aerobic exercise alone (SMD = 0.30) or a combination of aerobic, resistance, and flexibility exercises (SMD = 0.57) yielded the most significant improvements in cardio-respiratory fitness. The final study examined the efficacy of pre-surgical aerobic exercise (prehabilitation) therapy in relation to post-operative cardio-respiratory fitness, quality of life, and 30-day postoperative outcomes in the Grampians Region of Victoria. The prehabilitation (PREHAB) group included a supervised aerobic based program which would see patients exercise every two/three days for a minimum of 2 weeks. A total of 11 PREHAB and 9 usual care (UCARE) patients were enrolled and analysed. The study showed that a prehabilitation exercise program resulted in small clinical improvements in some markers of cardio-respiratory fitness (+1.5% and +1.2% for absolute and relative V̇O2peak, respectively) and is safe and feasible. However, no significant improvements were observed in quality of life and 30-day postoperative outcomes. While the overall findings demonstrate some positive effects of perioperative and specifically prehabilitation exercise, it is important to consider the magnitude of these effects and any specific factors contributing to their success, if applicable. Further research is needed to fully understand the potential benefits and limitations of exercise before, during and after surgery in this patient population.
Description:
Cancer is a prevalent disease with significant morbidity and mortality rates. Exercise interventions implemented before, during, or after cancer-based surgeries have shown promising benefits in improving fitness, postoperative complications, and quality of life. This thesis comprises three original research chapters aimed at investigating the effect of perioperative and preoperative 'prehabilitation' exercise in breast, colorectal, and prostate cancer patients. The first study focused on exploring exercise therapy interventions and their impact on cardio-respiratory fitness and 30-day postoperative outcomes in colorectal cancer patients. The systematic review and meta-analysis (N= 411 intervention and N= 368 control) revealed a small but significant improvement in cardio-respiratory fitness (SMD = 0.18; 95% CI = 0.03, 0.32; p < 0.05) with exercise interventions, although no significant impact on 30-day postoperative outcomes was observed. In the second study, various exercise types, including aerobic, resistance, flexibility, and mind-body exercises (alone or in combination), were compared in terms of their effect on cardio-respiratory fitness and 30-day postoperative outcomes in colorectal cancer patients (N= 411 intervention and N= 368 control). The network meta-analysis findings indicated that engaging in aerobic exercise alone (SMD = 0.30) or a combination of aerobic, resistance, and flexibility exercises (SMD = 0.57) yielded the most significant improvements in cardio-respiratory fitness. The final study examined the efficacy of pre-surgical aerobic exercise (prehabilitation) therapy in relation to post-operative cardio-respiratory fitness, quality of life, and 30-day postoperative outcomes in the Grampians Region of Victoria. The prehabilitation (PREHAB) group included a supervised aerobic based program which would see patients exercise every two/three days for a minimum of 2 weeks. A total of 11 PREHAB and 9 usual care (UCARE) patients were enrolled and analysed. The study showed that a prehabilitation exercise program resulted in small clinical improvements in some markers of cardio-respiratory fitness (+1.5% and +1.2% for absolute and relative V̇O2peak, respectively) and is safe and feasible. However, no significant improvements were observed in quality of life and 30-day postoperative outcomes. While the overall findings demonstrate some positive effects of perioperative and specifically prehabilitation exercise, it is important to consider the magnitude of these effects and any specific factors contributing to their success, if applicable. Further research is needed to fully understand the potential benefits and limitations of exercise before, during and after surgery in this patient population.
Description:
In light of impending demographic shifts and projected strain on healthcare systems, this thesis set out to progress our putative understanding of the benefits of physical exercise on mental health in older adults aged 65 years and over. Herein, four studies of divergent research design interrogated the current knowledge base relating to the potential benefits of exercise in older adults with depressive symptomology. Study 1 set out to establish preliminary experimental evidence that four years of unsupervised aerobic exercise can improve cardiorespiratory function (determined by VO2max) and health-related quality of life (HRQL) in lifelong sedentary ageing men compared with lifelong exercising athletes. Results demonstrated preliminary proof of concept for exercise-induced benefits on cardiorespiratory function and HRQL in ageing men. Study 2 surveyed community-dwelling older adults (n = 586) to establish a hierarchy of exercise-associated factors to predict depressive symptomology. Contrary to expectation, exercise behaviour did not confer additional antidepressant effect, but was substantially predicted by exercise-induced mood, exercise self-efficacy, and social support (f2 = 0.993). Study 3 pooled evidence from randomised controlled trials (RCTs) to quantitatively compare the treatment effectiveness from aerobic, resistance and mind-body exercise training in older adults with pre-existing clinical depression, whereas Study 4 followed the same methodology in apparently health older adults without pre-existing clinical depression. Using network meta-analytical techniques, both clinical depressed (g = -0.41 to -1.38) and apparently healthy (g = -0.27 to -0.51) older adults demonstrated equivalent effectiveness for aerobic, resistance, and mind-body exercise interventions, with encouraging levels of study compliance. Taken together, these findings encourage personal exercise preference when prescribing either aerobic, resistance, or mind-body exercise as a treatment adjunct for clinical depression and older adults with symptoms thereof. The sum of works herein provide new knowledge to guide exercise prescription for stakeholders in mental health and older adults over 65 years.
Description:
In light of impending demographic shifts and projected strain on healthcare systems, this thesis set out to progress our putative understanding of the benefits of physical exercise on mental health in older adults aged 65 years and over. Herein, four studies of divergent research design interrogated the current knowledge base relating to the potential benefits of exercise in older adults with depressive symptomology. Study 1 set out to establish preliminary experimental evidence that four years of unsupervised aerobic exercise can improve cardiorespiratory function (determined by VO2max) and health-related quality of life (HRQL) in lifelong sedentary ageing men compared with lifelong exercising athletes. Results demonstrated preliminary proof of concept for exercise-induced benefits on cardiorespiratory function and HRQL in ageing men. Study 2 surveyed community-dwelling older adults (n = 586) to establish a hierarchy of exercise-associated factors to predict depressive symptomology. Contrary to expectation, exercise behaviour did not confer additional antidepressant effect, but was substantially predicted by exercise-induced mood, exercise self-efficacy, and social support (f2 = 0.993). Study 3 pooled evidence from randomised controlled trials (RCTs) to quantitatively compare the treatment effectiveness from aerobic, resistance and mind-body exercise training in older adults with pre-existing clinical depression, whereas Study 4 followed the same methodology in apparently health older adults without pre-existing clinical depression. Using network meta-analytical techniques, both clinical depressed (g = -0.41 to -1.38) and apparently healthy (g = -0.27 to -0.51) older adults demonstrated equivalent effectiveness for aerobic, resistance, and mind-body exercise interventions, with encouraging levels of study compliance. Taken together, these findings encourage personal exercise preference when prescribing either aerobic, resistance, or mind-body exercise as a treatment adjunct for clinical depression and older adults with symptoms thereof. The sum of works herein provide new knowledge to guide exercise prescription for stakeholders in mental health and older adults over 65 years.
Description:
In rodent models of human behaviour, physical activity builds stress resilience. In contrast, human studies physical activity and stress resilience have been limited, and when investigated, provided mixed results. These inconsistencies may be due to the ambiguous use of the term stress resilience in human studies, making it difficult to quantify. Therefore, I aimed to assess the effect of physical activity on stress resilience in humans, after first evaluating operational definitions of stress resilience. Initially, I evaluated the use of stress resilience across the literature to provide a definition that is consistent with the research base (Chapter 2). I subsequently defined stress resilience as an active process of adapting to unpredictable and uncontrollable stimuli. In Chapter 3, I systematically reviewed measures previously used to capture stress resilience in humans, including trait-based questionnaires, as well as affective and cardiorespiratory responses to stressful conditions. In Study 1 (Chapter 4) of this dissertation, I then assessed the convergent validity of these stress resilience measures , including the Brief Resilience Scale and the Connor-Davidson Resilience Scale, as well as various responses (i.e., affective balance, systolic blood pressure, rate pressure product, and multiple indices of heart rate variability) to three stressor conditions (i.e., no stress, auditory startles, and stressful video clips). Results of Study 1 indicated that no measure captured all elements of stress resilience, although some indices of heart rate variability were related to changes in affective balance and systolic blood pressure was related to the Brief Resilience Scale. Across two studies, I then evaluated the effect of physical activity on stress resilience using the measures from Study 1. Through a cross-sectional study (Study 2, Chapter 5), I found no difference between active participants (n = 16) and less active participants (n = 14) across stress resilience measures. Additionally, in Study 3 (Chapter 6), I found that an 8-week moderate physical activity intervention had no effect on these stress resilience measures in 14 participants from desk-based occupations. I did, however, find an increase in mood and reduction in systolic blood pressure post-intervention, compared to pre-intervention scores. I also discussed the feasibility of various recruitment techniques, intervention purity and adherence, as well as stress resilience measurement protocols for future intervention studies. Overall, this dissertation has provided a critical evaluation of the use and measurement of stress resilience, with findings indicating that physical activity may not enhance stress resilience in humans. I discuss differences in my findings, compared to rodent research, including the potential effects of environment enrichment and increased severity of measurement protocols in animal models. I also discuss limitations of stress resilience conceptualisation and provide suggestions for future research to navigate these challenges.
Description:
In rodent models of human behaviour, physical activity builds stress resilience. In contrast, human studies physical activity and stress resilience have been limited, and when investigated, provided mixed results. These inconsistencies may be due to the ambiguous use of the term stress resilience in human studies, making it difficult to quantify. Therefore, I aimed to assess the effect of physical activity on stress resilience in humans, after first evaluating operational definitions of stress resilience. Initially, I evaluated the use of stress resilience across the literature to provide a definition that is consistent with the research base (Chapter 2). I subsequently defined stress resilience as an active process of adapting to unpredictable and uncontrollable stimuli. In Chapter 3, I systematically reviewed measures previously used to capture stress resilience in humans, including trait-based questionnaires, as well as affective and cardiorespiratory responses to stressful conditions. In Study 1 (Chapter 4) of this dissertation, I then assessed the convergent validity of these stress resilience measures , including the Brief Resilience Scale and the Connor-Davidson Resilience Scale, as well as various responses (i.e., affective balance, systolic blood pressure, rate pressure product, and multiple indices of heart rate variability) to three stressor conditions (i.e., no stress, auditory startles, and stressful video clips). Results of Study 1 indicated that no measure captured all elements of stress resilience, although some indices of heart rate variability were related to changes in affective balance and systolic blood pressure was related to the Brief Resilience Scale. Across two studies, I then evaluated the effect of physical activity on stress resilience using the measures from Study 1. Through a cross-sectional study (Study 2, Chapter 5), I found no difference between active participants (n = 16) and less active participants (n = 14) across stress resilience measures. Additionally, in Study 3 (Chapter 6), I found that an 8-week moderate physical activity intervention had no effect on these stress resilience measures in 14 participants from desk-based occupations. I did, however, find an increase in mood and reduction in systolic blood pressure post-intervention, compared to pre-intervention scores. I also discussed the feasibility of various recruitment techniques, intervention purity and adherence, as well as stress resilience measurement protocols for future intervention studies. Overall, this dissertation has provided a critical evaluation of the use and measurement of stress resilience, with findings indicating that physical activity may not enhance stress resilience in humans. I discuss differences in my findings, compared to rodent research, including the potential effects of environment enrichment and increased severity of measurement protocols in animal models. I also discuss limitations of stress resilience conceptualisation and provide suggestions for future research to navigate these challenges.
Description:
"The purpose of this study was to evaluate the effect of cardioversion atrial fibrillation on exercise performance as measured by the level of anaerobic threshold."
Description:
"The aim of this study was to examine the effect of consecutive bouts of acute exhaustive exercise in a hot ambient environmemt on baroreflex gain, plasma volume and heart variability one week post-exercise in trained individuals." Problem with pages xviii-xx Pages 9-37 missing.
Description:
"The aim of this study was to examine the effect of consecutive bouts of acute exhaustive exercise in a hot ambient environmemt on baroreflex gain, plasma volume and heart variability one week post-exercise in trained individuals." Problem with pages xviii-xx Pages 9-37 missing.
Description:
"The primary purpose of this dissertation is to elucidate the mechanisms and sources of fluid contributing to exercise-induced hypervolemia. The second aim is to identify changes in blood volume regulation that act to retain this fluid in the vascular space. A final aim is to identify the mechanisms responsible for inducing training bradycardia".
Description:
The purpose of this investigation was to study how individuals internalise the health and fitness ethic and to consider how this ethic is expressed in individuals' exercise regimes. Consideration is given to what causes individuals to exercise in this manner and what impact it has on their embodiment.
Description:
"The present study was concerned with the effect of lactate tolerance training and a period of reduced training on the energy systems and associated performance."
Description:
Thesis (Master of Science (Human Movement)
Description:
"The present study was concerned with the effect of lactate tolerance training and a period of reduced training on the energy systems and associated performance."
Description:
Thesis (Master of Science (Human Movement)
Description:
"The purpose of this investigation was to determine the comparative effects of training by jogging, circuit weight training, swimming and calisthenic/endurance games on middle-aged men."
Description:
"The purpose of this investigation was to determine the comparative effects of training by jogging, circuit weight training, swimming and calisthenic/endurance games on middle-aged men."