Regular moderate-vigorous physical activity (MVPA) is associated with significant physiological and psychological health benefits (Department of Health, DoH, 2004). However, many children are not undertaking recommended levels of physical activity (PA) (DoH, 2009). This research examined relationships between physiological health parameters, psychological determinants and PA levels in 10-14 year old schoolchildren (N = 249) and assessed the influence of three school-based PA interventions on these constructs in the context of the Health And Physical activity Promotion in Youth (HAPPY) study. Study 1 revealed that sedentary behaviours, moderate PA (MPA), vigorous PA (VPA) and MVPA levels were higher on weekdays than weekend days (p < .001). However, schoolchildren’s PA is often difficult to measure accurately. The self-report measure utilised in study 2 underestimated total MVPA versus accelerometry for both sexes on weekdays and girls on weekend days (p < .01). However, study 3 highlighted a lack of agreement between two RT3® triaxial accelerometer cut-offs for all activity categories. The importance of VPA for promoting health was highlighted in the updated PA guidelines (DoH, 2011). Study 4 reported that cardiorespiratory fitness (CRF) was positively associated with VPA but not MPA (β = .27, p < .01) and inversely correlated with measures of body composition (% body fat; body mass index; waist circumference) (r = -.74, r = -.60, r = -.39, p < .001). Knowing the health benefits of regular MVPA and VPA, it is important to understand the determinants of PA intentions and behaviours to more effectively promote PA in less active children (studies 5 and 6). An exploratory analysis of the constructs in the Revised Theory of Planned Behaviour and the Modified Social Learning Theory for children predicted PA intentions (R2 = .38, F(5, 171) = 20.19, p < .001; R2 = .13, F(6, 147) = 3.4, p < .01, respectively) but the constructs in either model were unable to predict PA. Recognising the need to promote PA levels, study 7 investigated the effectiveness of three school-based interventions (vs. control) on outcome variables included in studies 1, and 4-6. The Health Education and Psychology Health Promotion conditions produced significant positive change scores between data collection 2 and 3 for CRF (vs. control) whereas the Youth-Led condition produced significant change scores between baseline and data collection 2 for generalised self-efficacy (vs. control). No significant change scores were reported for PA, the RTPB constructs or intentions. In conclusion, this research has emphasised the importance of employing a multidisciplinary approach to aid understanding of schoolchildren’s PA levels. Specific highlights include low weekend day PA as a possible future PA promotion target, although it is vital that accelerometry cut-points are standardised, and the relevance of VPA and body composition in predicting CRF. The psychological models identified some important determinants of PA intentions, but a prominent intention-behaviour gap and a need for more intensive interventions to promote PA levels was apparent.

The investigation of exercise specific left ventricular (LV) adaptations to training have been predominantly cross sectional in design. The purpose of the current thesis was to investigate LV adaptations to short term (6-9 weeks) training to establish if any changes are exercise specific. A correlation study was used to investigate correlations between cardiac variables and MAXOV2&(study 1). Cardiac variables were found to be the strongest predictors for absolute MAXOV2&, MAXOV2&BM and MAXOV2&FFM in cyclists compared to the total sample or sedentary group, predicting 79% (p<0.01), 70% (p<0.01) and 77% (p<0.01) of the variance, respectively. Secondly, it was found that when MAXOV2& was scaled to body mass (BM) or fat free mass (FFM) cardiac variables predicted less of the variance than for absolute MAXOV2&, for all groups. Study 2 investigated the hypothesis that there would be no evidence of LV hypertrophy when there was no increase in FFM. This was achieved by taking sedentary participants through a resistance training programme of 6 weeks duration to control for increases in skeletal muscle hypertrophy. Both resting systolic blood pressure (sBP; p = 0.01, d = 1.19) and diastolic blood pressure (dBP; p = 0.029, d = 0.88) were significantly reduced following the 6 weeks resistance training. One repetition maximum (1RM) bench press significantly increased (p = 0.00, d = -1.44) as did 1 RM parallel squat strength (p = 0.00, d = -1.86), with no associated increases in relative FFM (p = 0.45) or absolute LM (p = 0.87). There was no adaptation to LV morphology (p>0.05), however early diastolic function changed with a significant decrease in peak E wave (p = 0.00, d = 1.94). Study 3 compared differences in the time course of the initial adaptations to LV structure and function during 9 weeks of aerobic, resistance and combination exercise ii training, to establish whether LV adaptations are exercise specific. The resistance and combination groups demonstrated increases in relative wall thickness (p = 0.021, ηp2 = 0.408; p = 0.004, d = -1.06, respectively). PWd also significantly increased in the combination group (p = 0.032, ηp2 = 0.301); however there were no structural adaptations evident in the aerobic group (p > 0.05). In contrast, the aerobic group demonstrated functional adaptations with a decrease in A wave (p = 0.44, d = 0.87) as did the combination group (p = 0.002, ηp2 = 0.407). The results of the training studies showed limited support for the Morganroth Hypothesis as structural adaptations demonstrated LV remodelling of the myocardial tissue, with no increase in LV mass. Further to this, combination training appears to have an additive effect of LV adaptations of both aerobic and resistance training.

UK health and safety legislation aims to protect employees from injury at work; professional footballers as employees are therefore covered by this legislation. A risk assessment approach to health and safety issues, as required by the Management of Health and Safety at Work Regulations 1992, has been undertaken to establish the epidemiological and aetiological factors related to injuries in professional football and to identify management and training procedures to reduce the incidence and severity of injuries. Issues of injury frequency and causation during the period 1994 to 1997 were addressed through two routes. First, during the 1994 World Cup Finals, 1996 European Championships, and 1994 to 1997 English league seasons via match analysis. Second, player injuries at four professional football league clubs were recorded by the club physiotherapist. These results provided complementary evidence showing an overall injury rate of 8.5/1000 playing hours, injury rates during training and matches being 3.5/1000 and 27.7/1000 playing hours, respectively. Two thirds of the injuries occurred during competitive match play, the remainder during training, the highest incidences of match and training injuries taking place during the first month of the playing season (P<O.05) and the pre-season period (P<0.05), respectively. The lower extremity was the site of 87% of the reported injuries, 41% and 22% of all injuries being muscular strains and re-injuries, respectively. Injury profiles differed between youth and senior players (P<0.01). Additional information was recorded through an assessment of club training routines and a survey of professional footballers' knowledge and application of injury prevention strategies. Issues relating to current injury prevention practices, player's perception of injury risk and advice received relating to these issues were addressed. These results provided supportive evidence showing poor understanding of and adherence to accepted athlete training procedures and the implementation of injury prevention practices. The studies suggest that a substantial number of injuries could be prevented in English professional football through identification of the hazards presented to players, an assessment of the existing risk levels and implementation of more rigorous control measures. Deficiencies in injury prevention practices indicate a need for wider education of players and coaches regarding the hazards and risks associated with professional football and the availability of medical and sports science knowledge to reduce these levels of risk.

The desire to age well is a common goal among the human population. How to do so is therefore, a popular question. One theory of ageing involves the accumulation of damage to mitochondrial protein and the subsequent loss of function the damage causes. Increasing the rate of mitochondrial protein synthesis, a variable that declines with advancing age, is one way to improve quality of life in the twilight years. A review of literature lead to a multi-level approach, with measurements of protein synthesis made at the whole body, muscle, and molecular levels. An acute bout of aerobic exercise, followed by feeding, two factors which have a positive effect on the rate of mitochondrial protein synthesis, was used. Adaptations to a period of exercise training are mediated by the accumulation of proteins due to each acute exercise bout, and so an acute intervention was postulated to be indicative of changes expected over the long term. A stable isotope infusion combined with sampling of breath, blood, and muscle was used to determine the rate of whole body protein synthesis in 12 older adults. Intracellular signalling for mitochondrial and whole body protein synthesis was examined using RT-quantitative PCR and Western blotting in eleven young adults. The rate of post-exercise whole body protein synthesis was 19% greater over the first four hours of post-exercise recovery, in subjects receiving a protein-plus-carbohydrate drink immediately after a bout of cycling than in those receiving a carbohydrate-only drink (p = 0.001). The same trend was revealed in signalling for whole body protein synthesis and the abundance of cytochrome c, a mitochondrial protein, although these results were not statistically significant (p = 0.2). In contrast there was a strong, albeit also statistically insignificant, tendency for signalling for mitochondrial protein synthesis to be higher in the skeletal muscle of subjects receiving a carbohydrate-only drink after a bout of cycling (p = 0.06). The exercise and feeding intervention described in this thesis may provide a means to enhance the rate of mitochondrial protein synthesis in older individuals and, in so doing, improve the quality of their old age.

No description available.

The desire to age well is a common goal among the human population. How to do so is therefore, a popular question. One theory of ageing involves the accumulation of damage to mitochondrial protein and the subsequent loss of function the damage causes. Increasing the rate of mitochondrial protein synthesis, a variable that declines with advancing age, is one way to improve quality of life in the twilight years. A review of literature lead to a multi-level approach, with measurements of protein synthesis made at the whole body, muscle, and molecular levels. An acute bout of aerobic exercise, followed by feeding, two factors which have a positive effect on the rate of mitochondrial protein synthesis, was used. Adaptations to a period of exercise training are mediated by the accumulation of proteins due to each acute exercise bout, and so an acute intervention was postulated to be indicative of changes expected over the long term. A stable isotope infusion combined with sampling of breath, blood, and muscle was used to determine the rate of whole body protein synthesis in 12 older adults. Intracellular signalling for mitochondrial and whole body protein synthesis was examined using RT-quantitative PCR and Western blotting in eleven young adults. The rate of post-exercise whole body protein synthesis was 19% greater over the first four hours of post-exercise recovery, in subjects receiving a protein-plus-carbohydrate drink immediately after a bout of cycling than in those receiving a carbohydrate-only drink (p = 0.001). The same trend was revealed in signalling for whole body protein synthesis and the abundance of cytochrome c, a mitochondrial protein, although these results were not statistically significant (p = 0.2). In contrast there was a strong, albeit also statistically insignificant, tendency for signalling for mitochondrial protein synthesis to be higher in the skeletal muscle of subjects receiving a carbohydrate-only drink after a bout of cycling (p = 0.06). The exercise and feeding intervention described in this thesis may provide a means to enhance the rate of mitochondrial protein synthesis in older individuals and, in so doing, improve the quality of their old age.

The desire to age well is a common goal among the human population. How to do so is therefore, a popular question. One theory of ageing involves the accumulation of damage to mitochondrial protein and the subsequent loss of function the damage causes. Increasing the rate of mitochondrial protein synthesis, a variable that declines with advancing age, is one way to improve quality of life in the twilight years. A review of literature lead to a multi-level approach, with measurements of protein synthesis made at the whole body, muscle, and molecular levels. An acute bout of aerobic exercise, followed by feeding, two factors which have a positive effect on the rate of mitochondrial protein synthesis, was used. Adaptations to a period of exercise training are mediated by the accumulation of proteins due to each acute exercise bout, and so an acute intervention was postulated to be indicative of changes expected over the long term. A stable isotope infusion combined with sampling of breath, blood, and muscle was used to determine the rate of whole body protein synthesis in 12 older adults. Intracellular signalling for mitochondrial and whole body protein synthesis was examined using RT-quantitative PCR and Western blotting in eleven young adults. The rate of post-exercise whole body protein synthesis was 19% greater over the first four hours of post-exercise recovery, in subjects receiving a protein-plus-carbohydrate drink immediately after a bout of cycling than in those receiving a carbohydrate-only drink (p = 0.001). The same trend was revealed in signalling for whole body protein synthesis and the abundance of cytochrome c, a mitochondrial protein, although these results were not statistically significant (p = 0.2). In contrast there was a strong, albeit also statistically insignificant, tendency for signalling for mitochondrial protein synthesis to be higher in the skeletal muscle of subjects receiving a carbohydrate-only drink after a bout of cycling (p = 0.06). The exercise and feeding intervention described in this thesis may provide a means to enhance the rate of mitochondrial protein synthesis in older individuals and, in so doing, improve the quality of their old age.

The desire to age well is a common goal among the human population. How to do so is therefore, a popular question. One theory of ageing involves the accumulation of damage to mitochondrial protein and the subsequent loss of function the damage causes. Increasing the rate of mitochondrial protein synthesis, a variable that declines with advancing age, is one way to improve quality of life in the twilight years. A review of literature lead to a multi-level approach, with measurements of protein synthesis made at the whole body, muscle, and molecular levels. An acute bout of aerobic exercise, followed by feeding, two factors which have a positive effect on the rate of mitochondrial protein synthesis, was used. Adaptations to a period of exercise training are mediated by the accumulation of proteins due to each acute exercise bout, and so an acute intervention was postulated to be indicative of changes expected over the long term. A stable isotope infusion combined with sampling of breath, blood, and muscle was used to determine the rate of whole body protein synthesis in 12 older adults. Intracellular signalling for mitochondrial and whole body protein synthesis was examined using RT-quantitative PCR and Western blotting in eleven young adults. The rate of post-exercise whole body protein synthesis was 19% greater over the first four hours of post-exercise recovery, in subjects receiving a protein-plus-carbohydrate drink immediately after a bout of cycling than in those receiving a carbohydrate-only drink (p = 0.001). The same trend was revealed in signalling for whole body protein synthesis and the abundance of cytochrome c, a mitochondrial protein, although these results were not statistically significant (p = 0.2). In contrast there was a strong, albeit also statistically insignificant, tendency for signalling for mitochondrial protein synthesis to be higher in the skeletal muscle of subjects receiving a carbohydrate-only drink after a bout of cycling (p = 0.06). The exercise and feeding intervention described in this thesis may provide a means to enhance the rate of mitochondrial protein synthesis in older individuals and, in so doing, improve the quality of their old age.

Change of direction speed (CODS) is an important determinant of performance in many sports. Greater stiffness of the lower limb should be beneficial to CODS, but this had not been well investigated. The purpose of this thesis was to establish the relationship between vertical stiffness, vertical stiffness asymmetries and CODS, with a view to augmenting CODS performance. The pilot study and studies 1-2 sought to determine the most reliable and ecologically valid method to assess stiffness in athletes required to perform changes of direction. The pilot study reported that the use of ultrasonography to determine Achilles tendon stiffness did not demonstrate appropriate reliability for inclusion in subsequent studies. Coefficients of variation (CVs) in excess of 27% were reported during an isometric plantar flexion task. Study 1 reported that CVs for vertical stiffness were lower when assessed during unilateral drop jumping (~7%) than during bilateral drop jumping (~12%) or bilateral hopping (~14%). Study 2 reported that the expression of vertical stiffness (P = 0.033) and vertical stiffness symmetry angle (P = 0.006) was significantly different across three performance tasks: unilateral drop jumping, bilateral drop jumping and bilateral hopping. Asymmetry percentages between compliant and stiff limbs were 5.6% (P < 0.001; d: 0.22), 23.3% (P = 0.001; d = 0.86) and 12.4% (P = 0.001; d = 0.39), respectively. Given the findings of studies 1 and 2, this thesis demonstrated the reliability and validity of a novel method by which to assess vertical stiffness - the unilateral drop jump. This task was used in subsequent studies to measure vertical stiffness. Study 3 sought to determine if vertical stiffness and vertical stiffness asymmetries influenced CODS performance determined during a 90o cutting task. Multiple regression analyses reported that mean vertical stiffness and asymmetry in jump height explained 63% (r2 = 0.63; P = 0.001) of CODS performance. Study 3 was the first investigation to demonstrate the importance of vertical stiffness to CODS performance. Study 4 sought to determine if acute exercise interventions designed to augment vertical stiffness would improve CODS. Unilateral and bilateral ‘stiffness’ interventions were evaluated against a control condition. CODS performances following the unilateral intervention were significantly faster than control (1.7%; P= 0.011; d = -1.08), but not significantly faster than the bilateral intervention (1.0% faster; P = 0.14; d = -0.59). Versus control, vertical stiffness was 14% greater (P = 0.049; d = 0.39) following the unilateral intervention. Study 4 demonstrated that a novel unilateral ‘stiffness’ intervention improved vertical stiffness and CODS performance. This highlights that the potential applicability of unilateral stiffness interventions in the pre-performance preparation of athletes.

Numerous studies point to a link between fine motor skills and executive functioning (EF) in 3- to 6-year-olds (e.g., Oberer et al., 2017; MacDonald et al., 2016); however, it is unclear if this relation exists at younger ages. Therefore, the current project aimed to further explore EF and fine motor skills in typically developing 2-year-olds. Participants completed the Minnesota Executive Function Scale (MEFS), Spin the Pots, Shape Stroop, Snack Delay, and the Fine Motor portion (FMQ) of the Peabody Developmental Motor Scale Version-2. These findings demonstrate a link between general EF and visual-motor integration in 2-year-olds.