Introduction: Scientific investigations to determine physiological demands and performance characteristics in sports are integral and necessary to identify general fitness, to monitor training progress, and for the development, prescription and execution of successful training interventions. To date, there is minimal evidence based research considering the physiological demands and physical characteristics required for the equestrian sport of Eventing. Therefore, the overarching aim of this thesis was to investigate the physiological demands of Eventing and performance related fitness in female riders. Method: The primary aim was achieved upon completion of three empirical studies. Chapter Three: Anthropometric and physical fitness characteristics and training and competition practices of Novice, Intermediate and Advanced level female Event riders were assessed in a laboratory based physical fitness test battery. Chapter Four: The physiological demands and physical characteristics of Novice level female event riders throughout the three phases of Novice level one-day Eventing (ODE) were assessed in a competitive Eventing environment. Chapter Five: The physiological demands and muscle activity of riders on live horses in a variety of equine gaits and rider positions utilised during a novice ODE, including jumping efforts, was assessed in a novel designed live horse exercise test. Results: Chapter Three reported that aside from isometric endurance, riders anthropometric and physical fitness characteristics are not influenced by competitive level of Event riding. Asymmetrical development in isometric leg strength was reported with increased levels of performance; riders reported below average balance and hamstring flexibility responses indicating limited pelvic and ankle stability, and tightness in the hamstring and lower back. Chapter Four reports that physiological strain based upon heart rate during Eventing competition is considerable and close to maximal, however blood lactate data was not supportive of this supposition. Chapter Five reports that during horse riding, riders are exposed to intermittent and prolonged isometric muscle work. During horse-riding, riders have an elevated heart rate compared to the oxygen requirements for the activity, in addition to moderate blood lactate concentrations. Conclusion: This thesis indicates that the most physiologically demanding aspect of Event riding is the light seat canter and where jumping efforts are introduced. During these positions and gait combinations, heart rate is elevated compared to oxygen uptake. Additionally, moderate blood lactate (BLa) concentrations are reported suggesting though cardiac strain is high, physical demands are moderate. The use of heart rate as a marker of exercise intensity during horse riding activities is not appropriate as it is not reflective of actual physiologic demand and BLa may be a more indicative marker of exercise intensity for equestrian investigations. There are many factors that may affect heart rate as discussed throughout the thesis, such as cognitive anxiety, heat stress and isometric muscle work. The data from this thesis speculates that the elevated heart rate is in part affected by isometric muscle work; similar physiological profiles exist in sports such as Sailing and are attributed to the quasi isometric theory. Though this thesis is not able to comprehensively conclude that physiological responses are a direct result of quasi isometrics, the data set does infer this may be a potential contributor and as such is a recommended topic for future research. Regardless of the causal mechanism, riders should be conditioned to tolerate high heart rates to enable optimal physical preparation for competition; the physical characteristics and physiological demands placed upon Event riders reported throughout this thesis provides information for coaches and trainers to consider when designing such interventions.

This work investigated relationships between neck pain, cervical proprioception and ocular motor performance. Systematic literature reviews identified moderate quality evidence for greater cervical joint positioning errors (JPE) in the transverse plane among participants with whiplash, but low-to-very low quality evidence for participants with non-traumatic neck pain, and for other cervical and ocular tests. Limited low quality evidence indicated little correlation between performance across tests, questioning their construct validity for cervical proprioception. Test-retest studies established adequate intra-examiner reliability of a smooth-pursuit (SPNT) test, a novel, non-predictable ocular tracking test and of cervical JPE and cervico-cephalic kinesthesia tests. A cross-sectional study found impaired non-predictable ocular tracking performance in mechanical neck pain, compared with healthy participants. The construct validity of this, and of existing tests, was evaluated by examining convergence of correlation in their performance. In healthy participants, convergence between cervical JPE, cervico-cephalic kinesthesia and ocular tracking tests, indicated common neurological processes. In the neck pain group there was convergence only between the cervico-cephalic kinesthesia and ocular tracking tests. A theoretical model suggested that impaired cervical proprioception or cognitive functions underlie deficits in neck pain, while adaptations in vestibular gain or efference copy underlie the absence of impairment in the cervical JPE test.

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.

There is a large inter-subject variability in the capacity to oxidise fat (MFO) during exercise and this could have important implications for metabolic health. Chapter 3 of this thesis was designed to explore the relationship between MFO with 24-h fat oxidation and insulin sensitivity. This study showed that MFO during exercise is significantly and positively associated with 24-h fat oxidation and insulin sensitivity. Chapter 4 investigated relationships between selected plasma metabolites, hormones and overnight-fasted resting fat oxidation rates, with MFO. Plasma lipolytic markers, plasma insulin, resting fat oxidation and aerobic capacity were important modulators of the inter-subject variability in MFO. Chapter 5 explored the influence of meal timing around exercise on substrate utilisation, lipolytic markers and insulin, and intra-muscular triglyceride (IMTG) use in obesity. This study found that Fasted- as compared with Fed-state exercise augments exercise fat oxidation, and the circulating concentration of plasma glycerol and NEFA during exercise. This thesis generates new data that contributes to our understanding of the links between MFO and metabolic risk, as well as the factors that influence the inter-subject variability in MFO during exercise. It also shows that fasted exercise augments exercise fat oxidation, which could have meaningful implications for optimising metabolic health.

Over two thirds of the UK population do not meet physical activity (PA) recommendations set by the Department of Health (2011) to improve or maintain health. It is therefore essential to focus research on effective and efficient methods to promote autonomous reasons to engage and persist in PA. Employing a variety of research designs this thesis explores the social contextual and environmental determinants, predominantly from a Self-Determination Theory perspective, of PA adoption, persistence and psychological well-being (Study 1; qualitatively). Study 2 and 3 examined unique sources of support from within and beyond a PA programme including human and non-human sources (i.e., technology). Study 3 employed an intervention focusing on the effect of autonomy supportive text messages on PA behaviour and well-being. Deriving from findings of Study 1, the final study (4) investigated the effect of the physical environment and PA levels on affective states. Results highlight the importance and relevance of socio-contextual (considering each unique contribution of individual sources of support) and environmental determinants (moderate intensity PA within a natural outdoor environment being key for positive high activation) in the promotion of PA. Findings carry important practical implications for those involved in promotion of long-term PA behaviour.

An accumulation of epidemiological studies along with several lines of experimental research highlight sustained elevated resting heart rate as a significant predictor of cardiovascular morbidity and mortality. However, resting heart rate as a simple and inexpensive clinical parameter often remains overlooked by physicians. We therefore sought to raise awareness concerning the detrimental role of elevated resting heart rate in cardiovascular disease. Using three separate large prospective cohort studies, we examined the clinical importance of accelerated resting heart rate as a robust predictor of adverse cardiovascular prognosis. The current data supports the contention that a raised resting heart rate amplifies the risk of having several cardio-metabolic risk factors including type 2 diabetes mellitus, the metabolic syndrome, and increased pulse wave velocity. Resting tachycardia also appeared to increase the risk of cardiovascular mortality in otherwise healthy individuals, as well as negatively predicting outcome in patients already at-risk for the condition. Notably, we observed a strong synergistic effect between inflammatory activity and concurrent elevated resting heart rate among those who experienced a cardiovascular event. Overall, these findings underline the relevance of a high resting heart rate in the pathogenesis of atherosclerosis and in the clinical manifestations of cardiovascular mortality.

Rheumatoid Arthritis (RA) is a chronic inflammatory disease that can negatively impact people both psychologically and physically. Health benefits of regular physical activity (PA) have been demonstrated for RA patients (Cooney et al., 2011), however people living with RA are more likely to be sedentary (Sokka et al., 2008; Yu et al., 2015). A Self-Determination Theory (SDT) based approach was adopted in this thesis. The validity and reliability of the Behavioural Regulation in Exercise Questionnaire-2 (BREQ-2) was tested (Chapter 2) within RA patients via a mixed method approach. In a second study (Chapter 3), hypothesised relationships based on SDT between autonomy support from the important other (s), basic psychological needs, motivation regulations and RA patients’ subjective vitality and self-reported PA was tested via structural equation modelling. Presumed mediation effects were also examined. As an incongruence between PA measurement has been found previously (Semanik et al., 2011), the agreement with self-reported PA and sedentary time (ST) were determined (Chapter 4) on both objective and subjective PA, then related to the VO2 max test. The next investigation (Chapter 5) assessed the associations between motivation regulations, objectively measured PA/ST and a key indicator of compromised mental health (i.e., depressive symptoms). Overall findings of this thesis were discussed in Chapter 6, and future research directions, practical implication and limitations proposed.

In the healthy human the primary driver for neuroplastic change is experience, in the form of learning and memory. Visuomotor learning has been shown as an effective experimental paradigm for inducing neuroplasticity, which is expressed as changes in corticospinal excitability (CSE). The present thesis uses the transcranial magnetic stimulation (TMS) stimulus response (SR) curve to assess learning induced changes in CSE. The first study presents a means of rapidly acquiring the TMS SR curve. Study two compares learning induced modulation of CSE between proximal and distal muscles. Study three assesses the influence of hand preference on learning induced changes in CSE. The results of study one indicate that it is possible to acquire the TMS SR curve in under two minutes. Studies two and three suggest distal muscles have a greater capacity for CSE modulation and this modulation of CSE is invariant to hand preference. Importantly, there is considerable variability in learning induced modulation of CSE. This thesis presents a novel paradigm for rapidly acquiring the TMS SR curve. It also highlights an important point for future studies of learning induced neuroplasticity – there is considerable variability in the neuroplastic response to a single session of visuomotor learning.

Attempts have been made to account for the increased propensity of upper respiratory tract infections (URTI) in regularly training individuals, by focusing on the effect of exercise on the primary mucosal immunoglobulin secretory immunoglobulin A (sIgA). However, the pathophysiological significance of observed changes in sIgA levels remains unclear, as indeed does the existence of increased URTI in athletes. The aim of this work was to examine the use of sIgA as a marker of exercise-induced immunomodulation and its possible role in protection against URTI. Before these questions could be addressed the optimum method for saliva collection, and the ideal terms for expression of sIgA levels were investigated. Experimental data advocate the use of the passive dribbling method above the use of salivettes. Salivettes were found to result in an underestimation of both saliva flow rate and protein concentrations as a consequence of limited absorption (3 ± 1ml) and variable retention of the sample (49.1 ± 24.9%). Secretory IgA levels are commonly expressed in terms of secretion rate which is the product of saliva flow rate and sIgA concentration. Examination of the relative contribution of these two factors to secretion rate revealed that exercise-induced changes in saliva flow rate (-51 %) matched the changes in secretion rate (-51 %), whereas changes in sIgA concentrations (+4%) did not. It was concluded that changes in saliva flow rates have an important role with the occurrence of symptoms associated with URTI whether induced by infective or inflammatory factors. Epidemiological data from others on the incidence of symptoms associated with URTI in marathon runners have provided evidence on the incidence of URTI in athletes. However here, reported symptoms associated with URTI were most common during the race suggesting that an infective agent was not involved. Examination of the effect of marathon running revealed a non-significant decrease in saliva flow rate (-27.7 ± 15.8%). A final study investigated the effect of increased ambient temperature, and the possibility of fluid replacement as a intervention strategy against exercise-induced decreases in saliva flow rate. This study revealed that exercise reduced saliva flow rate exercise in the heat exacerbated this and that fluid replacement tempered the exercise-induced decrease. Changes in saliva flow rate were found to be associated with changes in plasma volume. The overall conclusions of this thesis are that innate defence mechanisms such as saliva have a role to play in conferring defence against potential pathogens, and therefore warrant further investigation. It appears from data presented in this thesis that saliva flow rate is affected by exercise, perhaps to a greater extent than sIgA concentration. Changes in saliva flow rate with exercise may have a role to play in the purported increased incidence of URTI reported by athletes, and fluid replacement may provide an effective strategy against this exercise-induced decrease.

There is a lack of scientific research into roller hockey. The aim of this thesis was to analyse the muscular demands of roller hockey match play, using four techniques. These were a) Match analysis: Two Premier League roller hockey matches were recorded using two stationary video cameras. Manual, field-by-field analysis established all the actions performed by players in a match situation, the percentage of match time spent performing each action, their frequency and the mean duration of each action. Also recorded was the direction travelled, while the intensity of each action was subjectively assessed. b) Heart rate analysis (n=5): heart rate was recorded every 5 s during training and competition. Heart rate and performance were also measured during a maximal progressive 20-m shuttle skate test and oxygen consumption (V02) was calculated. c) Kinesiology analysis (n=l): Two-dimensional video analysis was used to establish the phases, joint actions, and muscular activity of each roller hockey action. d) Telemetric surface electromyography (EMG) analysis (n=6): activity was monitored in 8 muscles during training practice and training matches. The results of the match analysis showed 71% of match play was spent rolling, and 70% was spent travelling forwards; 22% was conducted at high intensity. Minor differences were found in match play activity between forwards and defenders, and between winners and losers. Comparisons between activity in the 1st and 2nd halves showed significantly more sprinting in the 1st half (p<0.05) and significantly more rolling and low intensity activity in the 2nd half (p<0.05). Mean heart rates during competitive matches (176 beats/min) were significantly higher (p<0.05) than during training matches (166 beats/min). The maximal 20-m shuttle skate test produced a mean predicted V02max, of 54 ml/kg/min, and maximal heart rates similar to competitive matches. The kinesiology analysis established 8 muscles central in roller hockey; these muscles were monitored in the EMG analysis. Electromyography revealed that performance of roller hockey actions during training produced the greatest EMG activity in the pectoralis major, while sprinting and forehand slap shots were the most demanding actions. Combining the results of the electromyography analysis with the match analysis revealed the high physical demands of shooting and the skating actions of pushing and sprinting. This thesis constituted the first long-term study of roller hockey, and it provided evidence that may be used in developing technique and improving sport specific fitness.