One public health approach to increase lifestyle physical activity is increasing choice to climb stairs instead of using the escalator or lift. Nonetheless, pedestrians in the built environment tend to avoid it. Proffitt’s economy of action model explained that pedestrian locomotor choices might influenced by perception. The first study (n=870) revisited Shaffer and Flint (2011) by asking participants to estimate the angle of an escalator. Participants reported an escalator that was moving upwards as less steep than a stationary one or one moving downwards. The second study (n=849), conducted in Indonesia, assessed the potential effects of temperature and humidity on a) speed of climbing an outdoor staircase and b) estimates of the angle. Chosen speed is an index of the allocation of resources. As temperature increased, speed of climbing reduced. For perception, both temperature and humidity influenced the explicit estimate of the angle; as climatic variables increased, perceptions became more exaggerated. Study three (n=730) and four (n=307), in the UK, are a concomitant study that investigated pedestrians’ behaviour approaching the choice-point and examined the relationship between behaviour choice and perceived steepness of a staircase. Results revealed that individuals who climbed the stairs walked faster than those who avoided them. Unlike a previous study, exaggeration of perceived steepness of the stairs did not affect pedestrians’ choice behaviour. Collectively, these findings suggest that availability energetic resources influence the overestimation of perceived steepness. In addition, natural variation in climate not only affects explicit perceptions but also directly influence both walking and climbing behaviour.

Oxidative stress and inflammation are two reciprocally linked processes that characterise many disease states, but can also transiently increase in response to a range of stimuli, including exercise, to initiate adaptation. This thesis presents novel data indicating that oxidative stress did not increase in response to an acute mental arithmetic challenge, under resting conditions or experimentally induced high baseline inflammation. In the context of exercise, chapters 3, 4 and 5 support previous work that markers of plasma and peripheral blood mononuclear cell (PBMC) oxidative stress increase in response to acute exercise. Acute exercise (30-40 min, 70% VO2MAX) in rheumatoid arthritis patients caused a transient increase in protein carbonylation that over a period of training (3 months, 3 sessions per week) at the same intensity did not increase global oxidative stress or inflammation. Plasma 3-nitrotyrosine decreased with exercise training, alongside improvements in disease activity and aerobic fitness. The last two experimental chapters of this thesis explored acute changes in plasma (Chapter 4) and PBMC (Chapter 5) oxidative stress in response to bouts of low volume high intensity interval training (LV-HIIT) and steady state exercise (60% maximal oxygen consumption (VO2MAX), 27 minutes and 80% VO2MAX, 20 minutes). LV-HIIT provided an anti-inflammatory (IL-6 and IL-10) and anti-oxidant (plasma total antioxidant capacity and PBMC thioredoxin protein content) response to exercise that paralleled the response (magnitude and timecourse) observed with steady state exercise of high and moderate intensity.

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).

Cardiovascular control during exercise results from three main mechanisms, namely central command (descending neural input), skeletal muscle afferent feedback (metabo - and mechanoreflex) and the arterial baroreflex. The studies outlined in this thesis sought to examine the potential sex- and ovarian hormone influences in neural cardiovascular control during exercise. It was observed that the activation of metabolically sensitive skeletal muscle afferents (i.e. muscle metaboreflex) by partial restriction of blood flow to the exercising skeletal muscle contributes to the exercise tachycardia via a reduction in cardiac baroreflex sensitivity from rest during dynamic exercise. Importantly, the magnitude of this metaboreflex-mediated reduction in cardiac baroreflex responsiveness was not different between men and women during the early and late follicular phases of the ovarian cycle. Baroreflex perturbation during dynamic exercise, by means of hypotensive and hypertensive stimuli to the carotid baroreceptors, revealed that baroreflex control of blood pressure was similarly maintained during exercise in men and women. Finally it was demonstrated that the sympathetic vasoconstriction in the exercising limb is similarly blunted in men and women. Overall, the results of this thesis suggest that there are no differences between men and women in baroreflex function and sympathetic vascular responsiveness during dynamic exercise.

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.

The role of the shaft in the golf swing has been the subject of scientific debate for many years but there is little consensus regarding the effects of altering shaft bending stiffness. The aim of this thesis was to determine and explain the effects of changes in shaft stiffness on body kinematics, shaft strain and key performance indicators including club head speed, impact location on the club face and launch conditions. For this purpose, three clubs matched in all properties but shaft bending stiffness (l-flex (217 cpm), r-flex (245 cpm) and x-flex (272 cpm)) were instrumented with strain gauges. In an initial study, seventeen male golfers (handicap 1.8 ±1.9) tested these clubs, but no shaft effects on body kinematics, club head speed and ball launch conditions were identified. A follow-up study involved twenty skilled players (handicap 0.3 ±1.7), testing only the l- and x-flex clubs. Two optical motion capture systems were used to determine wrist angular kinematics, club head presentation and the ball's impact location on the club face. There was an effect of shaft stiffness on ball and club head speed, both of which increased by 0.7 % for the l-flex club (p = 0.008 and < 0.001, respectively). Two factors contributed to these increases: (i) a faster recovery of the l-flex shaft from lag to lead bending just before impact (p < 0.001); (ii) an increase of 0.5 % in angular velocity of the grip of the l-flex club at impact (p = 0.005). A difference in angular wrist kinematics between the two clubs was identified for two swing events and may have contributed to the increase in angular velocity. The face angle (p = 0.176) and the ball's impact location (p = 0.907 and p = 0.774) were unaffected by changes in shaft stiffness. Decreases in shaft stiffness were associated with significantly more shaft bending at the transition from backswing to downswing (p < 0.001), but the amount of lead bending at impact was found to be largely unaffected by shaft stiffness. The test protocol from the follow-up study was repeated using a golf robot, confirming the results for ball speed and wrist kinematics if the impact speed was set to replicate the mean club head speed achieved by the human players. Results from this thesis contradict the conventional view that reducing shaft stiffness leads to an increase in lead bending at impact and, consequently, to an increase in ball launch angle. Overall, these results suggest that it is unlikely that changes in overall shaft stiffness in themselves have a marked effect on driving performance.

The detrimental nature of movement variability has recently been reconsidered with suggestions that it has a functional role to play in performance. Movements in golf can be attributed to the organismic, task and environmental constraints from which they emerge with these swing movements affecting shot outcomes. A three-dimensional analysis of address position variability revealed that higher skilled golfers present reduced alignment variability in angular relationships between the shoulders and stance compared to less skilled counterparts. Whilst there were no group differences in impact variability, both points in the swing displayed reducing variability from proximal to distal aspects of the kinetic chain. With the popularity of strength and conditioning growing within the golfing world it has become important for coaches to be able to assess golfers’ physical constraints. Two-dimensional analysis, representative of that used in coaching environments, assessed the relationship between the overhead squat and deterioration of posture in the golf swing. Results showed small but significant relationships between this test and golf swing postural kinematics. An 8-week intervention to address overhead squat physical constraints resulted in no change in 3D swing kinematics. Strength and conditioning as a stand-alone intervention provides no benefits to postural kinematics suggesting the need for coaching.