This research explored the lived experience of becoming an Applied Sport and Exercise Scientist. To become an accredited independent practitioner within the British Association of Sport and Exercise Science neophyte practitioners are required to undertake supervised experience. A review of contemporary literature revealed a paucity of research exploring the training and development of applied practitioners within sport and exercise science. Consequently, educational learning theory provided a vehicle from which to understand and critique related literature and provide context to analytical interpretations. Van Manen’s (1990) hermeneutic phenomenological approach to human science guided the research process. This provided a middle ground between description and interpretation from which to explore participant experience. Semi-structured interviews were conducted with fifteen supervisees and nine supervisors to elucidate the lived experience of becoming an Applied Sport and Exercise Scientist. Digitally recorded data were transcribed verbatim and analysed via phenomenological thematic analysis. Template analysis was drawn upon to support the analytical process and assist in organisation of themes. To gain an in-depth understanding of participant experience the hermeneutic circle provided a means of remaining cognisant of fore-conceptions, whilst allowing original findings to emerge. A number of themes were identified from which two essential themes were derived from the essential structure of the experience; ‘Being and learning relationships are predicated upon the emotion derived from interpersonal relationships’ and ‘Mutual participation enables movement towards independence’. Establishing trust and an emotional bond provided meaning within the supervisory dyad. Active participation from both supervisee and supervisor enabled reciprocity and supervisee development. This research raises awareness for supervisees, supervisors and supervisory processes regarding the importance of interpersonal relationships within the training and development of applied practitioners. Future research is suggested to focus upon both supervisees’ and supervisors’ longitudinal experiences and their recommendation for the introduction of formal peer mentoring post accreditation.

It is well known that physical activity can bring many benefits to people as they become older. In addition, a great deal is known about the personal and environmental motivators and barriers for older adults engaging in physical activity, yet policy imperatives have failed to deliver the change in activity levels required to even relatively modest levels of activity. This study has sought to ascertain the effect of involving older adults in the design, delivery, implementation and promotion of interventions to promote physical activity amongst their age group. Through a two phase design the study has sought to find out what the essential ingredients of a successful intervention to promote physical activity would be, before applying some of these findings to the promotion of interventions and considering their effect. The first phase of the study consisted of a qualitative study to identify older adults’ views and experiences. Some 61 older adults, aged between 49 and 87 years, were involved in 11 focus groups and 12 individual semi-structured interviews. Participants were asked why they engaged in physical activities, or what might encourage them to do so. The study was designed to identify the essential elements of a successful physical activity intervention. The second phase of the study, an action research project evolving from the qualitative study, involved older adults who were running community groups and physical activity sessions in their local areas and were keen to increase membership numbers. The Action Research Group, consisting of six older adults, two community development workers and the researcher, identified a number of problems to address as part of the study. New promotional literature for the community groups was developed, using the findings from the first study. Easy access, enjoyment, fun and affordability were highlighted on posters and leaflets that were distributed in the local communities. The studies established that there are various factors that make engaging in physical activities accessible and appealing to older adults. Participants reported that activities must be flexible; affordable; accessible; sociable; enjoyable and that engagement is seasonal. Factors relating to personality and lifestyle were also important. Not feeling the need to be active, and being unmotivated to do so, cannot be easily influenced by external promotion of physical activity. However, ensuring that activities are as easy as possible to engage in could help to encourage older adults to try activities that they might otherwise rule out. The health benefits of physical activity were far less important to the participants than the social benefits. Involving older adults in the promotion of activities, focussing on the characteristics of activities that appeal to them, had some success. Difficulties in appealing to older adults across a broad age range emerged, as many participants in both studies were put off attending any activity labelled as for ‘over 50s’. They did not identify themselves as ‘over 50’. Both studies highlighted the additional difficulty of attracting men to existing activity groups and sessions. A multilevel, social ecological model is presented, which highlights the influences on engagement in physical activity at individual and environmental levels. The future promotion of physical activity should focus on the social benefits and enjoyment that can be gained through participation, rather than on potential health benefits. How activities are labelled and promoted requires careful consideration and local older adults should be involved in local interventions. Community groups delivering interventions must receive tangible support.

Distortion to hemodynamic, ischemic and metabolic stimuli during low load resistance exercise with blood flow restriction (BFR) may influence regional vascular adaptation. This thesis investigated the acute response and chronic adaptations of the peripheral vasculature to low load resistance exercise with BFR. The methodology utilised Doppler ultrasound, strain gauge plethysmography and muscle biopsy for insightful measures of the vasculature at different regions of the arterial tree. Short term (4-6 weeks) localised low load (30-40% 1RM) resistance exercise with BFR increased brachial (3.1%) and popliteal (3.3%) artery maximal diameter (in response to ischemic exercise), forearm (29%) and calf (24%) post-occlusive blood flow, and calf filtration capacity (14%). These findings indicate potential vascular remodelling at the conduit (chapters 3, 4) resistance (chapter 4) and capillary (chapter 4) level of the vascular tree. Regional, rather than systemic, factors are responsible for these adaptations as evidenced by an absent response in the contralateral control limb. Transient improvements in popliteal artery FMD% occurred at week 2 before increased maximal diameter at week 6, suggesting functional changes precede structural remodelling (chapter 4). Maximal brachial artery diameter and forearm post-occlusive blood flow returned to baseline values after a 2 week detraining period, signifying rapid structural normalisation after stimulus removal (chapter 3). Enhanced capillarity, despite low training loads, could be explained by augmentation of VEGF (~7 fold), PGC-1α (~6 fold) and eNOS (~5 fold) mRNA, and upregulation VEGFR-2 (~5 fold) and HIF-1α (~2.5 fold) mRNA with BFR (chapter 5). This indicates a targeted angiogenic response potentially mediated through enhanced metabolic, ischemic and shear stress stimuli. Large between subject variability in the level of BFR was observed during upper and lower limb cuff inflation protocols. Adipose tissue thickness and mean arterial pressure were the largest independent determinants of upper and lower limb BFR, respectively (Chapter 6). In conclusion, this thesis demonstrates that low load resistance exercise with BFR induces adaptation in the conduit, resistance and capillary vessels. The mediators of this response are likely to be the hemodynamic and chemical signals elicited by repeated bouts of BFR resistance exercise, although confirmation of these mechanisms is required. The functional significance of these adaptations is unknown and warrants further investigation.

In recent years there has been growing interest in the role of gut hormones in regulating appetite, energy balance and weight control. Prominent among these hormones is the hunger hormone ghrelin which is the only circulating hormone currently known to stimulate appetite. A variety of hormones are known to suppress appetite and notable among these is peptide YY (PYY). Both ghrelin and PYY exist in more than one form with acylated ghrelin and PYY3-36 representing the biologically active forms of these hormones i.e. the form of each hormone with the most potent effects on appetite. Many studies have investigated ghrelin responses to exercise in male participants and some studies have also examined PYY responses. Far fewer studies have examined ghrelin and PYY responses in female participants and this was the primary purpose of the studies reported here. This thesis comprises four main experimental chapters which collectively sought to clarify whether there is any evidence to support the hypothesis that appetite, gut hormone and food intake responses differ in female compared with male participants. A total of 123 participants took part in the studies reported in this thesis. The first of these studies was cross-sectional in nature and compared fasting appetite, plasma acylated ghrelin and dietary restraint questionnaire values (among other variables) in 34 males and 33 females. No significant differences were observed between sexes for any of these variables. In the second study, appetite, plasma acylated ghrelin and ad libitum food intake responses to cycling exercise were examined in 13 female participants taking the oral contraceptive pill in both the luteal and follicular phases of the menstrual cycle. Although fasting hunger and prospective food consumption values were higher in the follicular than the luteal phase there was no difference in appetite, plasma acylated ghrelin and food intake responses to exercise between menstrual cycle phases. In the third study, appetite, plasma acylated ghrelin, plasma PYY3-36 and food intake responses to energy deficits created via diet and exercise were compared in 13 young, healthy female participants who completed three separate trials (control, exercise deficit and food deficit) in a random order. The findings revealed that, as with male participants, females experience compensatory appetite, gut hormone and food intake responses to dietary induced energy deficits but not to exercise induced energy deficits (over the course of a nine hour observation period). The final study reported in this thesis compared appetite, plasma acylated ghrelin and ad libitum food intake responses to a one hour run in 10 male and 10 female participants. Suppressions of both hunger and plasma acylated ghrelin were noted during exercise but there was no significant difference in the responses of males and females during or after exercise. Collectively, the studies reported here suggest: 1) that fasting appetite and plasma acylated ghrelin concentrations do not differ between male and female participants; 2) that appetite, ghrelin and food intake responses to cycling exercise do not differ according to the phase of the menstrual cycle in females; 3) that dietary restriction is more likely to elicit compensatory feeding responses than elevated exercise levels in females and 4) that males and females do not differ in their acute appetite, ghrelin and food intake responses to an acute bout of running exercise. Hence the studies reported here do not support the hypothesis that exercise will be less effective for controlling appetite and food intake in females than in males.

This thesis investigated the effect of exergaming versus mirror matched gym based exercise with no virtual stimuli on technology acceptance, flow and postural control in healthy young adults. Firstly a review of literature was performed analysing the effects of technology acceptance and flow on exergaming, and the effects of exergaming on postural control. Results showed the plausible nature of exergaming as an immersive environment and the potential to improve postural control. However, some major gaps in the literatures were identified. Technology acceptance had never been applied in exergaming and flow had only partly been applied to exergaming in limited studies. Additionally the effects of exergaming on postural control had shown some potential benefits, however no study had truly analysed the effects of exergaming on postural control by analysing mirror matched exercise with no virtual stimulus. The purpose of this thesis was to address these important areas of research and contribute novel evidence to the field. In two separate studies, 38 non active and 50 active young healthy adults took part in either exergaming based training or mirror matched gym based exercise with no virtual stimuli. Technology acceptance (behavioural intention), flow and postural control were measured at pre and post exercise intervention. Technology acceptance results showed that performance expectancy was significantly higher in the exergaming group in both studies, as well as being a significant predictor of behavioural intention at both pre and post exercise testing. In the second study, only, performance expectancy, social influences, and behavioural intention where statistically significantly higher for the exergaming group compared to the mirror matched gym based exercise with no virtual stimuli on technology acceptance, highlighting greater levels of acceptance into the exercise environment. Flow results showed greater levels immersion in the exergaming groups, especially in terms of clear goals, unambiguous feedback, action awareness merging, transformation of time and loss of self- consciousness. The effects of exergaming on postural control showed significant improvements in anterior- posterior standard deviation and range for the exergaming group in study one, and improvements in medio-lateral range in study two. Study two also showed significant improvement over time (pre-post exercise) for medio-lateral SD, range and centre of pressure. Evidence from both studies suggests that exergaming may offer an immersive environment for exercise which has a positive effect on behavioural intention to keep using the exergaming system in the future. With regards to postural control evidence from both studies suggest that exergaming may offer a new method of exercise to improve static postural control.

It is known that during fluid restriction, obligatory water losses continue and hypohydration develops and that restricted energy intake leads to a concomitant restriction of all other dietary components, as well as hypohydration, but the specific effects of periods of fluid and/ or energy restriction on fluid balance, electrolyte balance and exercise performance have not been systematically described in the scientific literature. There were two main aims of this thesis. Firstly, to describe the effects of periods of severe fluid and/ or energy restriction on fluid and electrolyte balance; secondly, to determine the effect of electrolyte supplementation during and after energy restriction on fluid and electrolyte balance as well as energy exercise performance. The severe restriction of fluid and/ or energy intake over a 24 h period all resulted in body mass loss (BML) and hypohydration, but whilst serum osmolality increases during fluid restriction (hypertonic hypohydration), serum osmolality does not change during energy restriction (isotonic hypohydration), despite similar reductions in plasma volume (Chapter 3). These differences in the tonicity of the hypohydration developed are most likely explainable by differences in electrolyte balance, with fluid restriction resulting in no change in electrolyte balance over 24 h (Chapter 3) and energy restriction (with or without fluid restriction) producing significant reductions in electrolyte balance by 24 h (Chapter 3; Chapter 4; Chapter 5; Chapter 6; Chapter 7). Twenty four hour combined fluid and energy restriction results in large negative balances of both sodium and potassium, and whilst the addition of sodium chloride to a rehydration solution ingested after fluid and energy restriction increases drink retention, the addition of potassium chloride to a rehydration solution does not (Chapter 4). Supplementation of sodium chloride and potassium chloride during periods of severe energy restriction reduces the BML observed during energy restriction and maintains plasma volume at pre-energy restriction levels (Chapter 5; Chapter 6; Chapter 7). iv These responses to electrolyte supplementation during energy restriction appear to be related to better maintenance of serum osmolality and electrolyte concentrations and a consequential reduction in urine output (Chapter 5; Chapter 6; Chapter 7). Additionally, 48 h energy restriction resulted in a reduction in exercise capacity in a hot environment and an increase in heart rate and core temperature during exercise, compared to a control trial providing adequate energy intake. Whilst electrolyte supplementation during the same 48 h period of energy restriction prevented these increases in heart rate and core temperature and exercise capacity was not different from the control trial Chapter 8). In conclusion, 24-48 h energy restriction results in large losses of sodium, potassium and chloride in urine and a large reduction in body mass and plasma volume and supplementation of these electrolytes during energy restriction reduces urine output, attenuates the reduction in body mass and maintains plasma volume and exercise capacity.

Prolonged exercise has been associated with depressed immune function, and hence an increased risk of infection. However, several nutritional supplements may reduce or overcome this problem. Thus, the aims of this thesis were to investigate the effects of some nutritional supplements on athletes immune function. In study 1 (Chapter 3), effects of several vaccine stimulant dose on whole blood culture cytokine production was carried out to determine effective vaccine stimulant dose; which was found to be between a dilution of 4000 (dose 4) and 1000 (dose 6) of the original vaccine. This finding was used for the other studies (Chapter 4 and 5). In addition, the relationship between data obtained from Evidence Investigator analyser and enzyme linked-immuno-sorbent assay (ELISA) for IL-10 was analysed and the results show a positive strong correlation between them. In study 2 (Chapter 4), in vitro effects of various immunomodulatory nutritional compounds on antigen-stimulated whole blood culture cytokine production was investigated and it was found that caffeine and quercetin showed tendency towards decrease cytokine production as the doses were increased. On the other hand, an upward trend was evident with kaloba, where high dose of kaloba seemed to increase the cytokine production. Since kaloba appeared to act as an immunostimulant in vitro, its effects on the immune response to prolonged exercise were examined in study 3 (Chapter 5). However, 7 days kaloba supplementation (20 mg of the root extract) did not alter athletes immune response although prolonged moderate intensity exercise significantly decreased S-IgA secretion rate and concentration post-exercise with the values returning to baseline by 1 h post-exercise. A 14-strain probiotic supplement effects on salivary antimicrobial proteins at rest and in response to an acute bout of prolonged exercise was investigated in study 4 (Chapter 6). Unfortunately, 30 days supplementation of the 14-strain probiotic appeared not enough to induce any significant effects on salivary antimicrobial proteins. Lastly, in study 5 (Chapter 7), the effects of a Lactobacillus probiotic on healthy people, who tend to have a higher than normal incidence of infection due to exercise stress-induced immune impairment was studied. In summary, this 16-week intervention study on 267 athletes found that regular ingestion of the probiotic reduced the extent to which training was negatively affected in endurance athletes when infection was present, and increased both S-IgA concentration and secretion rate over time. But it did not appear to reduce URTI incidence or the duration and severity of URTI episodes. Two major confounding factors, namely the unexpectedly low incidence of URTI during the winter period and the lower baseline S-IgA in the probiotic group may have prevented potential beneficial effects of probiotic supplementation from being identified.

Following a spinal cord injury (SCI), participation in regular exercise can enhance physical capacity and performance in activities of daily living. With this in mind, the use of subjective ratings of perceived exertion (RPE) may provide an easy-to-administer alternative to traditional methods of regulating exercise intensity (e.g. heart rate and power output (PO)). A physically active lifestyle is also associated with a reduced risk of cardiovascular disease, in part because exercise exerts anti-inflammatory effects. Examining the plasma response of inflammation-mediating chemical messengers, known as cytokines, to traditional and novel exercise modalities may help maximise the anti-inflammatory potential of regular exercise. Participants with a cervical level SCI successfully self-regulated a 20 min bout of moderate intensity wheelchair propulsion (Chapter three). No differences in physiological or PO responses were observed during the imposed-intensity and self-regulated wheelchair propulsion in the trained population group. In a non-SCI group of novice wheelchair-users, a differentiated RPE specific to the exercising muscle mass (RPEP) was the dominant perceptual signal during submaximal wheelchair propulsion (Chapter four). The novice group successfully self-regulated a 12 min bout of moderate intensity wheelchair propulsion, comprising of a discontinuous 3 x 4 min protocol, using differentiated RPEP. In contrast, a more accurate self-regulation of light intensity wheelchair propulsion was observed when employing traditional overall RPE compared to RPEP. Following strenuous wheelchair propulsion, plasma concentrations of the inflammation-mediating cytokine interleukin-6 (IL-6) were significantly elevated in non-SCI and thoracic level SCI participants (Chapter five). Impaired sympathetic nervous system (SNS) function was associated with a reduced IL-6 response in participants with a cervical level SCI. The plasma IL-6 response to 30 min moderate intensity (60% VO2peak) arm-crank ergometry (ACE) was associated with an elevation in the anti-inflammatory cytokine IL-1 receptor antagonist (IL-1ra) independent of SNS activation (Chapter six). Light intensity ACE resulted in a small, significant plasma IL-6 response but no IL-1ra response. The addition of functional electrical stimulation-evoked lower-limb cycling to concurrent hand cycling, termed hybrid exercise, resulted in a greater plasma IL-6 response compared to moderate intensity hand cycling alone in participants with a thoracic level SCI (Chapter seven).

The principle aims of this work were two fold; firstly to identify the current dietary intakes (specifically dietary glycaemic carbohydrate (CHO)) and physical activity (PA) and cardiorespiratory fitness (CRF) levels of a UK, postpubertal, adolescent population (n = 105) and assess the relationship between these factors, adiposity and cardiometabolic health. Diet and health relationships were assessed whilst accounting for energy misreporting and controlling for levels of PA and CRF. The effect of excluding dietary misreporters on the associations between glycaemic CHO and health was assessed whilst comparing an established technique (the Goldberg equation) to a novel approach (the ratio of energy intake (EI) to energy expenditure (EE)), which utilised RT3 accelerometry data (EI:EE(RT3)). Associations of PA and metabolic risk factors were also assessed whilst comparing two child specific PA thresholds for the assessment of PA subcomponents. Secondly, the impact of a flexible, ad libitum, low GI dietary intervention on cardiometabolic health was examined in an „at risk‟, overweight, postpubertal, adolescent population. Glycaemic index (GI) but not glycaemic load (GL) was shown to be associated significantly with anthropometric measures (body mass index (BMI), waist circumference (WC)) and adiposity (body fat percentage (BF%)) in this general group of post-pubertal adolescents from Bedfordshire. When adjusting for dietary intake, CRF was also associated with adiposity but PA was not. The prevalence of misreporting varied depending on the method used to assess the validity of dietary intakes; between 23% and 31% increasing to 62.1% (in overweight) of adolescents under reported energy intakes and up to 11.1% over reported. The novel application of a triaxial accelerometer to measure EE resulted in more under and over reporters being identified than when compared to the widely used Goldberg equation. Increased dietary GI was associated with increased odds of having a high WC; however, associations between GL and other risk factors were less clear; no associations with risk were observed. Excluding dietary misreporters from analysis had important implications for these associations. Only after removal of misreporters by EI:EE(RT3) was a borderline significant positive association between GL and blood glucose (BG) revealed using multiple analysis of covariance (MANCOVA), that was not present in prior analyses. Increased GI (moderate vs low GI intake) was significantly associated with reduced high density lipoprotein cholesterol (HDL) and increased triglyceride (TG) levels (borderline significant) after removal of misreporters. In addition, using different PA thresholds to assess PA intensity resulted in different relationships between PA subcomponents and metabolic risk factors. Regardless of the threshold used, evidence suggested that limiting sedentary (SED) behaviour and engaging in moderate to vigorous PA (MVPA) is beneficial for blood pressure (BP) in this adolescent population. Additionally, irrespective of the threshold utilised, higher levels of vigorous PA (VPA) were associated with reduced odds of having a high clustered risk score and the associations observed between CRF and risk factors were stronger than those observed with PA. Despite a lack of significant improvement in individual metabolic risk factors as a result of the low GI (LGI) dietary intervention, there was a significant reduction in clustered risk score for the LGI group at week 12. A borderline significant improvement in glycated haemoglobin (HbA1c) was also observed as a result of the LGI intervention compared to those in the control group. Conversely, there appeared to be an unfavourable effect of the LGI diet on fasting insulin levels and thus the diet‟s impact on health overall is unclear. The small sample size of this randomised controlled trial (RCT) means that caution is required when interpreting the results. These data suggest that future research in this age group should target improvements in CRF and a lower dietary GI to reduce adiposity. Controlling for dietary misreporting appears to have a significant impact on associations of glycaemic CHO and cardiometabolic health and should be an important consideration of future research. The low GI intervention may be an effective approach for reducing glycaemic CHO, whilst maintaining a healthy macronutrient intake, in comparison to more restricted dietary regimens published in the literature. However, the impact of this regime needs to be confirmed utilising a larger sample of adolescents. This may provide a useful approach for future research aiming to assess the impact of reduced GI and GL.

Increasing levels of physical activity in older adults and fall prevention are key concerns of current UK health policy. Regular physical activity has many positive benefits for older adults, for example in fall prevention. However, sedentary behaviour among older adults is common. Forty per cent of over 50s in the UK report less physical activity than is considered necessary to maintain good health. Sedentary behaviour is even more common in South Asian older people in the UK. The aim of this research was to investigate the attitudes and beliefs that drive or hinder uptake and adherence of physical activity, in general and in relation to fall prevention, among 60-70 year old Caucasian and South Asian community dwellers. An ethnographic method was chosen as the research approach as it provided the framework for facilitating the incorporation of multiple voices. Two main geographical areas were chosen to conduct the study and included eight sites of study. Data collection used multiple methods (participant observation, focus groups and semi-structured interviews). In total 60 hours of participant observation, 15 focus group discussions (n = 87; mean age = 65.74 years) and 40 semi-structured interviews (mean age = 64.83 yrs) were conducted. Data analysis and classification followed a framework approach, comparing and contrasting themes within and across groups. Findings demonstrate that older people do not recognise falls as a risk and are not motivated to perform physical activity on a regular basis purely to help prevent falls. Social support and social benefits of physical activity appear to be key motivators to initiating and maintaining physical activity. Enjoyment, increased self-confidence and developing social networks seem to be important motivators in terms of adherence. Health, although a good motivator for the initiation of physical activity, appears to be a secondary motivator in terms of adherence. Barriers to physical activity include perceived and actual poor physical health, lack of social support, specificity of physical activity messages by health professionals as well as lack of motivation, low mood, fear of harm and domestic and carer issues. These findings suggest that older adults should be assessed individually, to address physical symptoms and possible low mood, and not according to age. The importance of exercise, even in the presence of physical illness needs to be explained. There is a need to promote confidence in older people’s ability to perform an activity, as this appears to be essential in continuing with exercise. Activities that take a ‘one size fits all’ approach, serve as a de-motivating force. Variety in exercise and physical activity is important to maintain motivation in the long-term.