Physical inactivity is associated with dysregulation of intramuscular triglyceride (IMTG) metabolism leading to the accumulation of fatty acid metabolites and insulin resistance. This thesis aims to provide new information concerning the role of a subset of proteins associated with the metabolic regulation of IMTG-containing lipid droplets (LDs), known as the perilipin (PLIN) proteins, predominantly using immunofluorescence microscopy. Chapter 2 demonstrates that PLIN2-containing LDs are preferentially targeted for breakdown during moderate-intensity exercise in lean, sedentary males. Chapter 3 reveals that 6 months of endurance training (ET) in obese type 2 diabetes patients enhances PLIN2 content in type I fibres. Chapter 4 demonstrates that improvements in IMTG metabolism, including increased expression of PLIN2 and PLIN5, occur in response to both ET and sprint interval training (SIT) in lean, sedentary males. In Chapter 5 data is provided to show that RT also improves IMTG metabolism and insulin sensitivity in lean, sedentary males. Chapter 6 documents the effectiveness of a new constant-workload SIT protocol with regards to improving insulin sensitivity in obese individuals. In conclusion, this thesis generates novel data that contributes to our understanding of the underlying mechanisms that govern the relationship between IMTG metabolism and insulin sensitivity.

This thesis investigated how propositions of the Revised Applied Model for Deliberate Imagery Use (RAMDIU) related to imagery ability. Chapter 2 and 3 established that PETTLEP imagery can improve the ease and vividness of internal, external and kinesthetic imagery of movements. Participants perceived the physical and environments elements of the PETTLEP model to be the most helpful for imaging easily and vividly. Chapter 4 investigated the use of these two elements in athletes’ ease of imaging five different types of sport imagery (i.e., skill, strategy, mastery, goal, and affect). The findings revealed positive associations between the use of physical and environment PETTLEP elements and ease of imaging all five imagery types. The findings of Chapters 2 to 4 suggest that the use of physical environment elements will likely result in greater ease of imaging cognitive and motivational imagery content and that the relationship between “What (type) & How” and “Imagery Ability” in the RAMDIU should be bi-directional. Chapter 5 explored the RAMDIU “Who” component by investigating whether emotion regulation in was associated with their sport imagery ability. Only emotional reappraisal was positively related with “Imagery Ability”. Overall, the thesis establishing that imagery ability can be influenced by the individual’s characteristics and how athletes image. Practitioners should consider athletes’ characteristics and how they are going to image to maximize the effectiveness of the imagery intervention in achieving the desired outcome(s).

With the prevalence of obesity reaching epidemic levels both within the UK and worldwide there is an urgent need to explore ways in which to stem its burden on our society. There is a large body of research examining the positive effects of dietary and physical activity interventions for weight loss success, however much less is known regarding the psychological aspects, in particular the self-regulatory factors that contribute to both weight loss and weight maintenance success and failure. The current thesis examines these factors through four studies. Study one highlighted the factors related to success and failure in weight maintenance. Study two investigated the characteristics contributing to successful attainment of a weight loss and a non weight loss goal simultaneously. Study three explored the factors related to dietary lapse occurrence. Building on the previous studies, study four consisted of a self-regulatory skills intervention to improve weight-related outcomes. Results highlight the role of temptations and lapse occurrence and the threat they pose to weight loss and weight maintenance success. In addition, the current thesis outlines the need to not only identify influential self-regulatory factors but also to develop these factors in order to promote weight loss success.

This thesis aimed to investigate a novel way to explore changes in gaze behaviour, whilst walking, in frail populations. Initially three studies were conducted to establish how similar gaze behaviour recorded during walking was to that recorded whilst scene viewing. Duration of time and number of times different features were fixated were found to be similar in the three experiments. Older adults were assessed for falling risk and split into higher risk of falling (HROA) and lower risk of falling (LROA) groups. Their gaze behaviour was recorded whilst scene viewing along with a group of young adults. HROA were found to fixate the travel path longer than LROA and younger adults. HROA were slower at completing the incongruent Stroop task, suggesting a relationship between response inhibition and increased falling risk. A group of stroke patients were assessed for falling risk and split according to lesion location (parietal, occipital or frontal-temporal); gaze behaviour was recorded during scene viewing and compared to controls. Observable differences, which related to falling risk and lesion location, were shown in the gaze behaviour of the stroke patients compared to the controls. The findings of this thesis suggest that scene viewing could be used to better inform us about the changes in gaze behaviour which occur in frail populations that led to an increased risk of falling and the cognitive mechanisms which underlie these changes than laboratory studies.

The effects of exercise on appetite and feeding responses can be influenced by several factors. Research has demonstrated that exercise-induced changes in appetite can be affected by ambient temperature. Furthermore, exercise intensity has also been shown to affect appetite and post-exercise caloric intake. The aim of this thesis was to investigate the impact of exercise at different ambient temperatures on appetite and energy intake (EI) in overweight and obese individuals. Furthermore, this thesis also aimed to examine the effects of high intensity exercise on both peripheral and central appetite regulation in lean healthy males. The findings from this thesis demonstrated that exercise in a cold environment (8°C) stimulated post-exercise EI in overweight and obese men and women compared with exercise in a neutral environment (20°C). Exercise in the heat (32°C) caused an increase in desire to eat 5 hours post-exercise compared with rest in the heat in overweight and obese individuals, however no further differences in appetite sensations were observed between trials. Findings from this thesis have also demonstrated that an acute bout of intense running suppressed neural activation within the orbitofrontal cortex and hippocampus in response to images of high-calorie foods compared with rest. Furthermore, pictures of low-calorie foods enhanced activation within the insula and putamen post-exercise compared with rest. These central regions are associated with regulating the rewarding properties of food, therefore these findings showed that high intensity exercise is capable of suppressing the rewarding properties of high-calorie foods whilst enhancing the rewarding properties of low-calorie foods immediately post-exercise. However, an acute bout of intense running enhanced central reward system activation in response to food cues compared with rest several hours after exercise. Therefore, the appetite suppressing effects of an acute bout of high intensity exercise could be short-lived.

Protein and amino acid ingestion has been investigated as an aid in recovery from eccentric exercise induced muscle damage. However, the results of the studies are conflicting. There are two studies in this thesis that examine the effect of ingesting branched chain amino acids (BCAA) and protein following eccentric exercise in untrained males. Ingestion of BCAA resulted in a decrease in muscle soreness. However ingestion of whey protein isolate resulted in reduced muscle soreness and a reduction in the decrement of muscle function. These results suggest that ingestion of all amino acids are required to reduce decrements of muscle function associated with intense eccentric exercise. Ingestion of essential amino acids or intact protein sources during exercise recovery further stimulates muscle protein synthesis. The effect on muscle protein synthesis of ingesting only BCAA has not been investigated. Ingestion of BCAA increases phosphorylation status of signalling proteins associated with translation. This thesis demonstrates that following an acute bout of resistance exercise, ingestion of BCAA resulted in a 22% increase in muscle protein synthesis and 12% higher phosphorylation of S6K1THR389. These results suggest that only the ingestion of BCAA are required to augment the response muscle protein synthesis to exercise.

Low levels of cardio-respiratory fitness represent a major health risk. Few studies have investigated the possible contribution of psychological influences to cardio-respiratory fitness, with none longitudinally. The purpose of the present thesis was to explore the cognitive and behavioural correlates of adults’ cardio-respiratory fitness using theoretical constructs forwarded in Self-Determination Theory (SDT; Deci & Ryan, 2000) and the Theory of Planned Behaviour (TPB; Azjen, 1991). Studies 1 and 3 tested potential contributions of the Self Determination Theory cognitions of autonomous (intrinsic and identified) and controlled (introjected and external) motivations, including amotivation, to cardio-respiratory fitness over 9 weeks and 3 years. Studies 2 and 4 tested potential contributions from the Theory of Planned Behaviour constructs of intention, attitude, subjective norm and perceived behavioural control to cardio-respiratory fitness over the same time period. Analysis from structural equation modelling revealed only intrinsic motivation and affective attitude, constructs from the SDT and TPB respectively, contributed to changes in fitness. Collectively, the four studies suggest that intrinsic motivation and affective attitude are of major importance to cardio-respiratory fitness, even when individuals may have prominent controlled reasons for participating in exercise. The findings provide a foundation for theoretically aligned future research investigating the psychosocial antecedents of exercise with a view to developing more effective theory driven lifestyle interventions directed at enhancing this important health outcome.

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.

The development of talent is a complex process mediated by a host of psychology, social, physical, and environmental variables. Unfortunately, the multiple processes involved in talent development (Gagne, 2004; Simonton, 2001) are frequently ignored by the systems and protocols employed in sport. Modem approaches to talent development are beginning to stress the initial possession, then subsequent development, of Psychological Characteristics of Developing Excellence (PCDEs; MacNamara, Button, & Collins, 2010) as the best way to realize latent potential. Accordingly, the aim of this thesis was to acknowledge this complexity by identifying the psycho-behavioural factors that co-act with physical potential and practice regimes to enhance the efficacy of TID models in sport. The main objectives of this thesis were: 1. To identify the challenges faced along the pathway to excellence and the PCDEs that facilitate the successful negotiation of the pathway to excellence across different performance domains. 2. To identify whether PCDEs are operationalised differentially depending, on an individual's age, stage, and context. 3. To confirm these differential roles through quasi-longitudinal examinations of longterm employment (in musicians) and across a key transition (in athletics, the transitions to university at 18 years of age). 4. To develop a questionnaire to bridge the theory-practice divide in TO processes and enable formative evaluation of PCDEs by practitioners. 5. To provide preliminary validation of the questionnaire by evaluating its discriminant function between good and poor development athletes. The development of talent is a complex process mediated by a host of psychology, social, physical, and environmental variables. Unfortunately, the multiple processes involved in talent development (Gagne, 2004; Simonton, 2001) are frequently ignored by the systems and protocols employed in sport. Modem approaches to talent development are beginning to stress the initial possession, then subsequent development, of Psychological Characteristics of Developing Excellence (PCDEs; MacNamara, Button, & Collins, 2010) as the best way to realize latent potential. Accordingly, the aim of this thesis was to acknowledge this complexity by identifying the psycho-behavioural factors that co-act with physical potential and practice regimes to enhance the efficacy of TID models in sport. The main objectives of this thesis were: 1. To identify the challenges faced along the pathway to excellence and the PCDEs that facilitate the successful negotiation of the pathway to excellence across different performance domains. 2. To identify whether PCDEs are operationalised differentially depending, on an individual's age, stage, and context. 3. To confirm these differential roles through quasi-longitudinal examinations of longterm employment (in musicians) and across a key transition (in athletics, the transitions to university at 18 years of age). 4. To develop a questionnaire to bridge the theory-practice divide in TO processes and enable formative evaluation of PCDEs by practitioners. 5. To provide preliminary validation of the questionnaire by evaluating its discriminant function between good and poor development athletes. The development of talent is a complex process mediated by a host of psychology, social, physical, and environmental variables. Unfortunately, the multiple processes involved in talent development (Gagne, 2004; Simonton, 2001) are frequently ignored by the systems and protocols employed in sport. Modem approaches to talent development are beginning to stress the initial possession, then subsequent development, of Psychological Characteristics of Developing Excellence (PCDEs; MacNamara, Button, & Collins, 2010) as the best way to realize latent potential. Accordingly, the aim of this thesis was to acknowledge this complexity by identifying the psycho-behavioural factors that co-act with physical potential and practice regimes to enhance the efficacy of TID models in sport. The main objectives of this thesis were: 1. To identify the challenges faced along the pathway to excellence and the PCDEs that facilitate the successful negotiation of the pathway to excellence across different performance domains. 2. To identify whether PCDEs are operationalised differentially depending, on an individual's age, stage, and context. 3. To confirm these differential roles through quasi-longitudinal examinations of longterm employment (in musicians) and across a key transition (in athletics, the transitions to university at 18 years of age). 4. To develop a questionnaire to bridge the theory-practice divide in TO processes and enable formative evaluation of PCDEs by practitioners. 5. To provide preliminary validation of the questionnaire by evaluating its discriminant function between good and poor development athletes. To address the first and second objective, Chapter 3 describes a retrospective, qualitative study of the careers of elite performers. The findings of this study suggest that the pathway to excellence is complicated by the specific challenges faced within different performance domains. However, a similar set of PCDEs, albeit differentially deployed, were reported by all participants as facilitators of development. Chapters 4 and 5 employed a quasi-longitudinal research design to address Objective 3 - the differential deployment of PCDEs in particular contexts. Using a sliding populations methodology, young classical musicians were tracked over a 2-year period to explore the PCDEs employed during the macro and micro stages they encountered as they progressed. A similar research design was employed in Chapter 4 to examine the use of PCDEs during a critical transitional period for track and field athletes. Although the results point to the generality of PCDEs at both elite and developmental levels, and across performance domains, there appeared to be an understandable and necessary shift in responsibility from significant others promoting and reinforcing PCDEs in the early years towards self-initiated and autonomous behaviours in the later years; in essence, a shift in the source of regulation (Cleary & Zimmerman, 2001). The studies in Chapters 3, 4, and 5 generated a list of PCDEs that facilitated development, along with an understanding of how PCDEs were deployed differentially along the pathway to excellence. These findings were used to develop the Psychological Characteristics of Developing Excellence Questionnaire (PCDEQ); a questionnaire designed to assess the possession and strategic deployment of the PCDEs. Chapter 6 reported the systematic generation of questionnaire items and an exploratory factor analysis that resulted in a 59- item, 6 factor stnicture PCDEQ. The PCDEQ displayed good psychometric properties and should provide coaches with a theoretically and empirically supported tool to assess, monitor, and develop these key developmental skills. To address the final objective, Chapter 7 presents a discriminant function analysis which revealed that the PCDEQ had very good discriminant function and was able to classify between 67 per cent and 75 per cent of athletes correctly on the basis of their self-reported behaviour in sport. In conclusion, the studies reported in this thesis provide a significant contribution to current knowledge by shifting the fopus away from TID methods based on prediction and correlation towards a consideration of progress and behaviour during development. Future recommendations include the need for further validation of the PCDEQ as well as longitudinal and action-based research assessing the role of PCDEs in talent development.

This study investigates how young people and employers perceive equal opportunities in the world of work. Events such as the Stephen Lawrence Inquiry (Macpherson, 1999), the Race Relations (Amendment) Act 2000 and other legislation to promote equal opportunities, for example, Employment Equality Regulations, 2003 (Phillips, 2007, p.36) have placed this issue high on the political and education agenda. This study also investigates how young people perceive the message of equal opportunities in employers’ recruitment material as employers often declare in recruitment advertising that they are an equal opportunity employer (Dickens, 2000, p.138). A qualitative approach is taken using semi-structured interviews with thirty students in the sixth form in five secondary schools and five employers (The Army, The Fire Service, Metropolitan Police Service, British Airways and Mars UK) in West London. Policy documents on equal opportunities were also collected from the selected schools and employers. All the sources of data, that is the interviews with students and employers and the documentary data were analysed using a thematic approach. This study provides an in-depth insight and a snapshot at a local level of the national picture on equal opportunities in the world of work in relation to gender and ethnicity. The findings are that the young people, employers and the documentation of employers and schools show common understandings but also differences in their perception and portrayal of equal opportunities in the world of work. This study has also found that young people do not perceive the message of equal opportunities in the recruitment material. The implications of these findings are considered for both Careers Education and Guidance in schools and employers. This study concludes that the consensus is inspiring as it shows that young people and employers have a common vision of equal opportunities in the world of work and this consensus is followed through in policy documents. However, the differences, whilst they add variation to the perception and portrayal, need to be addressed if equal opportunities in the world of work are to progress further. To address these issues a model of Embedded Mutual Partnership is recommended between schools and employers.