The utility of well-being and physical performance assessments in managing the development of elite youth football players

Training stress in the absence of adequate recovery has been associated with a decrease in well-being and performance. Thus, there is potential for the high training and competition loads that elite English youth football players experience to have a negative effect on wellbeing and performance. The aim of the thesis was to assess the utility of well-being and physical performance assessments in managing the development of elite English youth football players. The first study (Chapter 4) examined the sensitivity of a subjective well-being questionnaire (WQ; developed ‘in-house’ by sport science practitioners at a category two academy and only taking < 30 s to complete), by comparing the player’s next day responses between two acute training bouts of varied duration; 15 mins (low load) compared to 90 mins (high load) high intensity intermittent exercise (Loughborough intermittent shuttle test, LIST). WQ items showed small to large deteriorations following the high load compared to low load (d=0.4-1.5, P=0.03-0.57). The ability of the WQ to differentiate between responses to high and low training loads indicated that this questionnaire could be used to detect training induced stress prior to training on a daily basis throughout the season. Other modes of monitoring assessment evaluated were either not sensitive to differentiate between high and low loads (countermovement jump; CMJ) or detected differences between high and low training load responses (HR indices) but lacked utility in detecting individual changes. The second study (Chapter 5) applied well-being and physical performance assessments to elite English youth football players during a high intensity, low volume pre-season training period. Trivial changes in perception of WQ items of sleep, recovery, appetite, fatigue, stress and muscle soreness were observed across weeks (P=0.35-0.93, 2 P  =0.02-0.08) with no negative WQ responses evident. Internal training load was lower to a large extent in week 1 (P=<0.001, 2P  =0.54) yet no differences in internal training load were evident across weeks two, three, four and five. Trivial to small associations (r=-0.21 to 0.19) between internal training load and WQ responses were observed. Small to moderate improvements in aerobic performance were evident post training in comparison with pre training (P<0.001-0.53, d= 0.33 – 0.94) with a large to moderate improvement in submaximal HR measures (P<0.001 – 0.09; 2 P  = 0.34 - 0.74) observed across the training weeks. Trivial to moderate impairments in neuromuscular performance were evident post training in comparison with pre training (P<0.001 – 0.21; d=0.17 – 1.00). Collectively, the preservation of well-being prior to each training session during a pre-season period and improvements in aspects of physical performance were indicative of a balance between stress and recovery. The third study (Chapter 6) examined player perceptions of well-being and physical performance across a season in Elite English youth football players. Increases in training exposure (P<0.05; 2 P  =0.52) and moderate to large deteriorations in perceptions of well-being (motivation, sleep quality, recovery, appetite, fatigue, stress, muscle soreness P<0.05; 2 P  =0.30-0.53) were evident as the season progressed. A large improvement in Yo-Yo intermittent recovery test performance (Yo-Yo IRT; P<0.05; 2 P  =0.93) and a small to moderate impairment in neuromuscular performance (P>0.05; 2 P  =0.18 - 0.48) was observed as the season progressed. These findings show an imbalance between stress and recovery in English elite youth football players even when players experienced lower training exposure than stipulated by the elite player performance plan (EPPP). In summary, this thesis highlights the potential utility of subjective well-being assessments to inform the management English elite youth football player development. Furthermore, it highlights the high training volumes that English elite youth players are exposed can potentially lead to an imbalance between stress and recovery

The Effectiveness of a Primary School Based Badminton Intervention on Children’s Fundamental Movement Skills

This study examined the effects of the Badminton World Federation (BWF) Shuttle Time program on fundamental movement skills (FMS) in English children. A total of 124 children; 66 in key stage 1 (ages 6&ndash;7 years) and 58 in key stage 2 (10&ndash;11 years) undertook the Shuttle Time program, once weekly for six weeks (n = 63) or acted as controls (n = 61). Pre, post and ten-weeks post, both process and product FMS were determined. Children in the intervention group, aged 6&ndash;7 years, had higher total process FMS (via test of gross motor development-2) compared to the control group at post and ten-weeks post intervention (both p = 0.0001, d = 0.6 and 0.7, respectively). There were no significant differences in process FMS scores for children aged 10&ndash;11 years. Ten-meter sprint speed decreased pre to post and was maintained at ten-weeks post for the intervention groups aged 6&ndash;7 years (p = 0.0001, d = 0.6) and 10&ndash;11 years (p = 0.001, d = 0.2) compared to control. Standing long jump distance increased pre to post (p = 0.0001, d = 0.8) and was maintained at ten-weeks post (p = 0.0001, d = 0.5) for the intervention group. Medicine ball throw performance increased pre to post (p = 0.0001, d = 0.3) for the intervention group. The BWF Shuttle Time program is beneficial in developing FMS for key stage 1 children (ages 6&ndash;7)

Low doses of caffeine: Enhancement of physical performance in elite adolescent male soccer players

Purpose: Large doses of ~6 mgkg-1 body mass (BM) have improved performance during intermittent running, jumping and agility protocols. However, there is sparse data on low doses of caffeine especially in elite adolescent soccer players. Method: 15 elite youth soccer players (177.3±4.8 cm, 66.9±7.9 kg and 16±1 yr) participated in the study. Participants consumed 1, 2 or 3 mgkg-1 caffeine in a gelatin capsule or a 2 mgkg-1 placebo in a single blind, randomised, crossover study design. Testing consisted of a 20 m sprint, arrowhead agility (CoD R or L), counter-movement jump (CMJ) and Yo-Yo intermittent recovery test level-1 (Yo-Yo IR1). Post-exercise CMJ performance was assessed as participants exited Yo-Yo IR1. Data were analysed using a Bayesian multi-level regression model to provide explained variance and probabilities of improvement (p=%). Results: 3 mgkg-1 caffeine presented the highest probabilities of change compared to placebo across a range of tests (mean ± SD, p= %). 20m sprint times were 3.15±0.10s vs 3.18±0.09s (p=73%), CoD-R times were 8.43±0.24s vs 8.55±0.25s (p=99%), CoD-L times were 8.44±0.22s vs 8.52±0.18s (p=85%), Yo-Yo IR1 distance were 2440±531m vs 2308±540m (p=15%), pre-exercise CMJ height was 41.6±7.2cm vs 38±8.5cm (p=96%). Post-exercise CMJ was higher in the 3 mgkg-1 compared to placebo (42.3±8cm vs 36.6±8cm [p=100%]). 1-2 mgkg-1 caffeine also demonstrated the ability to enhance performance but are task dependent. Conclusion: Low doses of caffeine improve performance but are dose and task dependent. 3 mgkg-1 caffeine improved performance across the majority of tests with potential to further improve post-exercise CMJ height

The Effects of Combined Movement and Storytelling Intervention on Motor Skills in South Asian and White Children Aged 5–6 Years Living in the United Kingdom

Early motor development has an important role in promoting physical activity (PA) during childhood and across the lifespan. Children from South Asian backgrounds are less active and have poorer motor skills, thus identifying the need for early motor skill instruction. This study examines the effect of a movement and storytelling intervention on South Asian children&rsquo;s motor skills. Following ethics approval and consent, 39 children (46% South Asian) participated in a 12-week movement and storytelling intervention. Pre and post, seven motor skills (run, jump, throw, catch, stationary dribble, roll, and kick) were assessed using Children&rsquo;s Activity and Movement in Preschool Study protocol. At baseline, South Asian children had poorer performance of motor skills. Following the intervention, all children improved their motor skills, with a bigger improvement observed for South Asian children. Early intervention provided remedial benefits to delays in motor skills and narrowed the motor skills gap in ethnic groups

Next Day Subjective and Objective Recovery Indices Following Acute Low and High Training Loads in Academy Rugby Union Players

The aim of this study was to determine the sensitivity of selected subjective and objective monitoring assessments in detecting changes in group and individual responses to low and high load bouts of high intensity intermittent exercise. In a counterbalanced crossover design, Thirteen Academy Rugby Union players (mean &plusmn; SD: age: 18 &plusmn; 1 years) performed a low load (15 min) and a high load (90 min) bout of high intensity intermittent exercise (Loughborough Intermittent Shuttle Test) one week apart. Monitoring assessments were performed immediately prior to and 20 h following each trial. Subjective self-report Well-being Questionnaire (WQ) items showed small to large deteriorations following the high load compared to low load (d = 0.4&ndash;1.5, p = 0.03&ndash;0.57). A very large increase in resting HR (HRrest) (d = 2.1, p = 0.02), moderate decrease in heart rate variability (HRV) indices (d = 0.7, p = 0.04 and d = 0.7, p = 0.01 for the natural logarithm of the standard deviation of R-R intervals (ln SDNN) and the root square of the mean squared differences of successive R-R intervals (rMSSD), respectively) and no change in countermovement jump (d = 0.0, p = 0.97) were evident following the high load compared to low load. Individual WQ responses revealed 7/9, 7/9, 6/9, 6/9, 5/9, 3/9 and 1/9 participants reported deteriorations in recovery, sleep quality, motivation, muscle soreness, fatigue, stress and appetite, respectively, following the high load compared to low load. Individual analysis indicated a negative response following the high load compared to low load in HRrest, ln SDNN and ln rMSSD for 4/6, 2/6 and 1/6 participants, respectively. Selected WQ items detected group and individual responses to high load and low load highlighting their potential utility. However, objective assessments lacked the sensitivity to detect small individual changes

Calibration and Cross-Validation of Accelerometery for Estimating Movement Skills in Children Aged 8-12 Years

This study sought to calibrate triaxial accelerometery, worn on both wrists, waist and both ankles, during children’s physical activity (PA), with particular attention to object control motor skills performed at a fast and slow cadence, and to cross-validate the accelerometer cut-points derived from the calibration using an independent dataset. Twenty boys (10.1 ±1.5 years) undertook seven, five-minute bouts of activity lying supine, standing, running (4.5kmph−1) instep passing a football (fast and slow cadence), dribbling a football (fast and slow cadence), whilst wearing five GENEActiv accelerometers on their non-dominant and dominant wrists and ankles and waist. VO2 was assessed concurrently using indirect calorimetry. ROC curve analysis was used to generate cut-points representing sedentary, light and moderate PA. The cut-points were then cross-validated using independent data from 30 children (9.4 ± 1.4 years), who had undertaken similar activities whilst wearing accelerometers and being assessed for VO2. GENEActiv monitors were able to discriminate sedentary activity to an excellent level irrespective of wear location. For moderate PA, discrimination of activity was considered good for monitors placed on the dominant wrist, waist, non-dominant and dominant ankles but fair for the non-dominant wrist. Applying the cut-points to the cross-validation sample indicated that cut-points validated in the calibration were able to successfully discriminate sedentary behaviour and moderate PA to an excellent standard and light PA to a fair standard. Cut-points derived from this calibration demonstrate an excellent ability to discriminate children’s sedentary behaviour and moderate intensity PA comprising motor skill activity.N/