Peter Mackreth

Background: The development of effective and sustainable childhood obesity treatment programmes is a public health priority. This pilot study evaluated the effectiveness of a local community collaboration (local council & local health care provider) in delivering a community based childhood obesity intervention following comprehensive training from our group. Methods: The Saturday morning intervention was delivered each week for a total of 12 weeks in a local secondary school. The family-based programme consisted of physical activity, nutrition and physical activity education, and behaviour modification. BMI, body composition, waist circumference, and aerobic fitness were assessed before and after the intervention. Statistical analysis was performed on an intention to treat basis. Results: Seventeen children (10 girls and 7 boys, aged 12.8±1.8 years) and at least one parent/carer per child were recruited to the programme, which had a mean attendance of 76.9% (± 22.9). Significant improvements (paired t test, P<0.05) were observed in BMI (-0.65±0.88 kg.m-2), BMI SD (-0.08±0.13 units), waist circumference (-2.47±4.73 cm), and predicted VO2 max from a one mile walk (6.05±9.19 ml.kg.-1min -1), while body fat percentage was maintained (-0.04±2.0%). Conclusion: The delivery of a childhood obesity intervention by a local community collaboration produced significant improvements in a variety of health variables. Such improvements, in combination with regular participant attendance and positive feedback from the local community collaboration regarding the training and delivery processes, suggest the current intervention to be effective. This community based approach is currently being delivered in several locations in the UK.

OBJECTIVE: To assess the long-term effects of a multidisciplinary approach involving structured fun-type skill learning physical activities in the treatment of obese and overweight children. DESIGN: A longitudinal investigation incorporating repeated measurements before and after the 8 week intervention and after the 44 week follow-up period. METHODS: The camp programme (Massachusetts, USA) utilised structured fun-based skill learning physical activities, moderate dietary restriction and behaviour modification. The primary aims of the intervention were to reduce body mass and promote the maintenance of the reduction in body mass using an alternative to standard exercise prescription. SUBJECTS: One-hundred and ninety-four children (64 boys and 130 girls, aged 12.6±2.5y) enrolled at a summer weight loss camp, of which 102 children (38 boys and 64 girls aged 13.6±2.4y) returned 1y later. MEASUREMENTS: On commencement of the programme all children were assessed for body mass and stature. At follow-up, data was available on 102 subjects for body mass and stature. RESULTS: Over the 8 week intervention significant reductions (P=0.00) in body mass were obtained. During the 44 week follow-up significant increases (P= 0.00) were noted in body mass, body mass index (BMI) and stature, but as expected there were large variations in the responses. One year after the initial measures had been taken mean body mass and BMI were lower than at the start of the intervention, BMI significantly so (week 0, 32.9 ± 7.4 kg/m

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Background: Prevalence of the metabolic syndrome has risen in children from 4.2% to 6.4% in 8 years (Duncan et al., 2004). Given this and the evidence that dietary modification and physical activity can favourably modify cardiovascular risk factors, the current study assessed the impact of an 8-week residential weight loss camp intervention on various biochemical and body composition variables. Methods: Fifty-one overweight and obese children (19 boys and 32 girls), mean age of 14.4 ± 2.0 years, BMI of 33.7 ± 7.2 kg/m2 and waist circumference of 95.5 ± 13.3 cm were resident at the camp intervention. Body composition and a range of biochemical variables were measured before and after the intervention (mean stay 31 ± 13 days). Results: Significant reductions (P < 0.001) were observed in all body composition variables, with BMI and waist circumference reduced by 5.6% and 5%, respectively. Significant reductions (P < 0.01) were observed for all biochemical variables except adiponectin. The following changes were achieved, T-C/HDL-c ratio (3.54 ± 0.76 pre to 2.99 ± 0.64 post), triglycerides (1.06 ± 0.41 mmol/L pre to 0.83 ± 0.32 mmol/L post), HOMA-IR (measure of insulin resistance) (3.46 ± 2.27 pre to 2.72 ± 1.77 post), C-reactive protein (measure of inflammation) (3.06 ± 2.79 mg/L pre to 1.71 ± 2.06 mg/L post), and leptin (125.0 ± 69.3 ng/mL pre to 55.7 ± 50.5 ng/mL post). Conclusion: Our programme achieved significant improvements in a variety of bio-chemical and body composition variables in a matter of weeks. This demonstrates the potential of this form of intervention for acute improvements. Further research is required to investigate the durability of these effects and the relationship with morbidity and premature mortality in adulthood.

Objective: The aim of the present study was to compare percentage body fat (PF) estimates using bioelectrical impedance analysis (BIA) with that determined by air displacement plethysmography in overweight and obese children. Methods: All participants had standardised BMI values >85th centile according to National Centile Charts. 302 males: age 13.9±1.7 y, BMI 32.8±6.6 kg.m-2, PF ADP 40.8±9.6 %, and 354 females: age 14.5±1.8 y, BMI 33.8±6.2 kg.m-2, PF ADP 44.2±7.2 %, were assessed. BIA PF estimates were obtained at 50 kHz using a foot-plate system device (Tanita TBF-310) and the inbuilt manufacturer prediction equations. ADP PF measurements were obtained using the child-specific thoracic gas volume prediction equations of Fields (2004) and the age and gender-specific body density conversion equations of Lohman (1989). Results: BIA estimates of PF were significantly correlated with those of ADP (males r=0.80, females r=0.68; both P<0.001). BIA significantly underestimated mean PF compared to ADP (males -3.6 %, females -1.7 %; both P<0.001). According to the methods of Bland and Altman, the ±95 % limits of agreement were slightly higher in males (±12.0 %) than females (±10.4 %). Further, correlation on the Bland and Altman plots revealed a significant bias as a function of increasing PF in females (r = - 0.45; P<0.001). Conclusion: On an individual basis there may be large discrepancies between BIA and ADP PF estimates. Results from devices are therefore not interchangeable in overweight and obese children.

Background: In 2004 the UK Government, within the Choosing Health White Paper, outlined a target ‘To halt, by 2010, the year on year increase in obesity among children under 11 in the context of a broader strategy to tackle obesity in the population as a whole’. In order to justify action there is a need to highlight the scale of the problem. In addition, further analysis comparing differences between schools is important to identify where appropriate resources/support should be provided. Methods: During 2005 BMI measurements were obtained in 2425 boys and 2267 girls, aged 11.6±0.3y, from 33 out of 40 schools in Leeds, UK. Standardized values were calculated using National Centile Charts and overweight and obesity prevalence defined at the 85th and 95th centiles, respectively. Results: Overall UK BMI centile charts identified 33.5% of children overweight and obese compared to the 27.7% prevalence reported in the Health Survey of England (2003) for children aged 9–11y. When the data were analysed by school the prevalence of overweight and obesity varied from 23.0% to 42.9%, with 3 schools less than 30% and 4 schools higher than 40%. Conclusion: These data should be of major concern given the increasing trend in an age group extremely close to that the government has prioritised. In addition, it is clear that there was large variability in the prevalence of overweight and obesity according to school. The upper prevalence values are particularly high and demonstrate the scale of the problem in children attending specific schools.

Background: UK levels of overweight and obesity in children are high and continue to increase (Health Survey of England 2004). Recently alternative methods to determine prevalence of overweight and obesity have gained recognition and been made available. Therefore this study was undertaken using three accepted methods for determining prevalence of overweight and obesity in a large sample of 11 year old children. Methods: 4711 children were assessed in 33 schools in Leeds, UK. All children were assessed for stature, body mass, waist circumference, % body fat and selected sports performance tests. Overweight and obesity was recognised using each of the three anthropometric measures (BMI, Waist circumference and % body fat) above the 85th percentile for age and gender. Results: Overweight and obesity prevalence was high with BMI, Waist circumference and % body fat mean prevalence being 34.4%, 47.9% and 25.2% respectively. Of concern was the high variability between schools, with the variation being 22.8% – 42.3% (BMI), 22.5% – 72.8% (waist circumference) and 16.4% - 36.9%% (Body fat). Conclusion: These data show that levels of childhood obesity are high in comparison to the 27.7% reported in the Health Survey of England (2004) and that there is high variation between schools in a large UK city. These findings provide strong evidence and information for targeted action in the form of both prevention and treatment for this population.

To compare the probability of tackle success (the tackler preventing the ball‐carrier and ball from progressing towards the tackler try‐line) when contacting the ball‐carrier at different heights (shoulder, mid‐torso and legs) for different types of tackles (active, passive, smother and arm) while accounting for other tackler situational factors within seven playing levels. Video footage of 271 male rugby union matches were analysed across seven playing groups (Under [U] 12, n = 25 matches; U14, n = 35; U16, n = 39; U18 Amateur n = 39; U18 Elite n = 38; Senior Amateur, n = 40 and Senior Elite, n = 50) across England, New Zealand, South Africa, Portugal and USA (a total of 51,106 tackles). A multi‐level logistic regression model with tackle success as the outcome variable and first point of contact and type of tackle as the explanatory variables were computed. Included in the model as cofounders were the situational variables tackle direction, tackle sequence, number of players in the tackle and attacker intention. Post‐estimation marginal effects were used to calculate the probabilities (expressed as a percentage %) of tackle success for each interaction between tackle type (active shoulder, smother, passive shoulder and arm) and the first point of contact (shoulder, mid‐torso and legs). The probability of tackle success in relation to where the ball‐carrier is contacted varied by tackle type and within each age group. The probabilities (Pr) for contacting the shoulder versus mid‐torso at the senior levels (elite and amateur) did not differ in relation to tackle success (for instance, for active shoulder tackles within senior elite; shoulder Pr 86% 95% CI 82–89 and mid‐torso Pr 82% 95% CI 77–86), whereas at the junior levels, contacting the shoulder had a higher probability than other points of contact. Active shoulder tackles had the highest probability of tackle success across the different playing levels across the different contact heights, whereas arm tackles had the lowest probability (for instance, for mid‐torso tackles within senior elite, active Pr 82% 95% CI 77–86 vs. arm Pr 69% 95% CI 64–75). Coaches and practitioners can use this information to improve tackle training design and planning within the different age groups and facilitate player development.

This study quantified and compared the collision and non-collision match characteristics across age categories (i.e. U12, U14, U16, U18, Senior) for both amateur and elite playing standards from Tier 1 rugby union nations (i.e. England, South Africa, New Zealand). Two-hundred and one male matches (5911 min ball-in-play) were coded using computerised notational analysis, including 193,708 match characteristics (e.g. 83,688 collisions, 33,052 tackles, 13,299 rucks, 1006 mauls, 2681 scrums, 2923 lineouts, 44,879 passes, 5568 kicks). Generalised linear mixed models with post-hoc comparisons and cluster analysis compared the match characteristics by age category and playing standard. Overall significant differences (p < 0.001) between age category and playing standard were found for the frequency of match characteristics, and tackle and ruck activity. The frequency of characteristics increased with age category and playing standard except for scrums and tries that were the lowest at the senior level. For the tackle, the percentage of successful tackles, frequency of active shoulder, sequential and simultaneous tackles increased with age and playing standard. For ruck activity, the number of attackers and defenders were lower in U18 and senior than younger age categories. Cluster analysis demonstrated clear differences in all and collision match characteristics and activity by age category and playing standard. These findings provide the most comprehensive quantification and comparison of collision and non-collision activity in rugby union demonstrating increased frequency and type of collision activity with increasing age and playing standard. These findings have implications for policy to ensure the safe development of rugby union players throughout the world.

Background: Athlete exposure to contact could be a risk factor for injury. Governing bodies should provide guidelines preventing overexposure to contact. Objectives: Describe the current contact load practices and perceptions of contact load requirements within men’s and women’s rugby league to allow the Rugby Football League (RFL) to develop contact load guidelines. Methods: Participants (n=450 players, n=46 coaching staff, n=32 performance staff, n=23 medical staff) completed an online survey of 27 items, assessing the current contact load practices and perceptions within four categories: “current contact load practices” (n=12 items), “perceptions of required contact load” (n = 6 items), “monitoring of contact load” (n=3 items), and “the relationship between contact load and recovery” (n=6 items). Results: During men’s Super League pre-season, full contact and controlled contact training was typically undertaken for 15-30 minutes per week, and wrestling training for 15-45 minutes per week. During the in-season, these three training types were all typically undertaken for 15-30 mins per week. In women’s Super League, all training modalities were undertaken for up to 30 minutes per week in the pre- and in-season periods. Both men’s and women’s Super League players and staff perceived 15-30 minutes of full contact training per week was enough to prepare players for the physical demands of rugby league, but a higher duration may be required to prepare for the technical contact demands. Conclusion: Men’s and women’s Super League clubs currently undertake more contact training during pre-season than in-season, which was planned by coaches and is deemed adequate to prepare players for the demands of rugby league. This study provides data to develop contact load guidelines to improve player welfare whilst not impacting performance.

Research in nutrition and health has primarily targeted the treatment of chronic diseases. However, research suggests food intake can also affect mood (Geary, 2001: The food and mood handbook. London: Thornsons). Food intake may impact important self-perceptions, however little is known of the role played by nutrition on self perception in children. This gave the purpose to the current study. With institutional ethical approval, 146 year 7 pupils (females [n=92]; mean age=11.60, s=0.32) completed a modified version of the Harter Self-Perception Profile for Children (SPPC; Harter, 1985: Manual of the self-perception profile for children. Denver, CO: University of Denver). The SPPC provides a multi-dimensional overview of an individual’s ratings of competence on five elements sports competence, appearance, social acceptance, scholastic competence and behavioural conduct, combining in a single score for Global Self Worth. Two questions were drawn from the original 6 per subscale. Participants also completed a Food Frequency Questionnaire (FFQ), comprising 63 food categories, with six levels for frequency of consumption (Margetts et al., 1989: International Journal of Epidemiology 18, 868–873). Separate standard portion sizes for boys and girls were used in the analysis (Macdiarmid & Blundell, 1997: European Journal of Clinical Nutrition, 51, 199–200). Data were collected during PE lessons at the beginning of the academic year. Based on responses participants were categorized as either high/low self-perceptions around the mean subscale split. Pearsons Product Moment correlations found no significant relationship between Global Self Worthand energy intake. However, there was a significantlynegative correlation between total energy intake and (i) Appearance (r(146)=-0.166, P=0.021 and (ii) Behaviour (r(146)=-0.210, P=0.036) subscales, suggesting that as total energy intake increased perceptions of appearance and behaviour decreased The results provide preliminary findings to support a potential relationship between energy intake and self-perceptions in children. Findings highlight that children who report higher energy intakes have reduced levels of self-perception in certain subscales. It suggests that while energy intake was not negatively related to Global Self-worth, it is negatively linked to perceptions at the lower domain levels of appearance and behaviour. This confirms a potential detrimental effect of increased energy intake with how children view the way they look and the way they behave. Findings suggest that schools should be aware of the risk that higher energy intakes may have on self-perceptions and seek to develop strategies to enhance their beneficial elements.

An increasing number of studies in children are being published using accelerometry to determine the levels of moderate-to-vigorous physical activity (MVPA). Although accelerometry is regarded as an objective measure, a review of the literature reveals a large disparity in the proportions of children meeting current MVPA recommendations. Therefore, the aim of the present study was to evaluate the variability of MVPA estimates in children using published accelerometry threshold values. With institutional ethical approval, 46 (27 males) children, aged 11–12 years, participated in the study. Weekday physical activity was measured using an Actigraph GT1M accelerometer, set at 10-s epochs. Time spent in MVPA was calculated using five adjusted intensity thresholds based on previously published counts per minute (cpm) values: (i) 1130 (Freedson et al., 1997: Medicine and Science in Sports and Exercise, 29, S45), (ii) 2000 (Ekelund et al., 2004: American Journal of Clinical Nutrition, 80, 584–590), (iii) 3000 (Treuth et al., 2004: Medicine and Science in Sports and Exercise, 36, 1259–1266), (iv) 3200 (Puyau et al., 2002: Obesity Research, 10, 150–157) and (v) 3600 (Riddoch et al., 2007: Archives of Disease in Childhood, 92, 963–969). Additionally, using each threshold the percentage of children acquiring an average of 60 min MVPA per day was calculated. Using the five intensity thresholds, participants spent (in ascending order) (i) mean 100, s=32 min, (ii) mean 59, s=23 min, (iii) mean 32, s=15 min, (iv) mean 28, s=13 min and (v) mean 21, s=11 min per weekday in MVPA, respectively. All differences were statistically significant (P<0.001). Within each threshold, the percentage of children acquiring an average of 60 min MVPA was 93, 41, 9, 2 and 0%, respectively. Although based on only a small sample, these findings illustrate the variability of defining MVPA using different thresholds. Although accelerometry overcomes many of the reliability and validity problems associated with self-report, pedometer and heart-rate assessment, careful consideration is warranted when interpreting accelerometry data. Indeed, even though acceleroAn increasing number of studies in children are being published using accelerometry to determine the levels of moderate-to-vigorous physical activity (MVPA). Although accelerometry is regarded as an objective measure, a review of the literature reveals a large disparity in the proportions of children meeting current MVPA recommendations. Therefore, the aim of the present study was to evaluate the variability of MVPA estimates in children using published accelerometry threshold values. With institutional ethical approval, 46 (27 males) children, aged 11–12 years, participated in the study. Weekday physical activity was measured using an Actigraph GT1M accelerometer, set at 10-s epochs. Time spent in MVPA was calculated using five adjusted intensity thresholds based on previously published counts per minute (cpm) values: (i) 1130 (Freedson et al., 1997: Medicine and Science in Sports and Exercise, 29, S45), (ii) 2000 (Ekelund et al., 2004: American Journal of Clinical Nutrition, 80, 584–590), (iii) 3000 (Treuth et al., 2004: Medicine and Science in Sports and Exercise, 36, 1259–1266), (iv) 3200 (Puyau et al., 2002: Obesity Research, 10, 150–157) and (v) 3600 (Riddoch et al., 2007: Archives of Disease in Childhood, 92, 963–969). Additionally, using each threshold the percentage of children acquiring an average of 60 min MVPA per day was calculated. Using the five intensity thresholds, participants spent (in ascending order) (i) mean 100, s=32 min, (ii) mean 59, s=23 min, (iii) mean 32, s=15 min, (iv) mean 28, s=13 min and (v) mean 21, s=11 min per weekday in MVPA, respectively. All differences were statistically significant (P<0.001). Within each threshold, the percentage of children acquiring an average of 60 min MVPA was 93, 41, 9, 2 and 0%, respectively. Although based on only a small sample, these findings illustrate the variability of defining MVPA using different thresholds. Although accelerometry overcomes many of the reliability and validity problems associated with self-report, pedometer and heart-rate assessment, careful consideration is warranted when interpreting accelerometry data. Indeed, even though accelerometry counts may be regarded as an objective assessment of physical activity, analysis of the data still requires a subjective choice of MVPA threshold. Moreover, until a quantifiable evidencebased definition of MVPA is developed in association with appropriate accelerometry thresholds, any conclusion regarding the proportions of 11–12 year old school children meeting current government guidelines must be interpreted with caution.

Objective Within women’s rugby league (n=12 teams), we (1) identified modifiers for head-to-head contacts informed by sport partners (eg, players, coaches, match officials); (2) compared head-to-head contact and concussion rates to the previous two seasons following a one-season tackle technique coaching intervention and (3) explored barriers and enablers of the intervention. Methods A multi-method design was used. Part 1: Mitigation strategies were identified by sport partners reviewing footage of head-to-head contacts, informing the development of a coach-targeted tackle technique intervention. Part 2 evaluated the intervention, comparing head-to-head contact and concussion incidence rates (IRs). Interviews with coaches and players (n=6) explored barriers and enablers to effective implementation and compliance with the intervention. Results Sport partners reported tacklers were more responsible for head-to-head contacts and lowering the tackle height was the most frequently suggested mitigation strategy preintervention and postintervention. Head-to-head contact rates were significantly lower during the intervention than preintervention (IR 59; 95% CI 56 to 62 vs IR 28; 95% CI 25 to 30/1000 tackle events); however, concussion rates showed no difference. Perceived barriers to the intervention included underdeveloped physical and technical foundations of players, lack of knowledge and understanding of the intervention and its purpose, and the environmental context and lack of resources in women’s rugby league. Beliefs about the consequences of the tackle and concussion were perceived as barriers and enablers. Conclusions Head-to-head contact rates were significantly lower; however, concussion rates did not decrease following a tackle technique coaching intervention. Reduced head-to-head contacts are potentially due to an increased focus on head injury reduction and increased player/coach awareness and support.

This is the first study to assess longitudinal changes in anthropometric, physiological, and physical qualities of international women’s rugby league players. Thirteen forwards and 11 backs were tested three times over a 10-month period. Assessments included: standing height and body mass, body composition measured by dual x-ray absorptiometry (DXA), a blood panel, resting metabolic rate (RMR) assessed by indirect calorimetry, aerobic capacity (i.e.,V˙O2max) evaluated by an incremental treadmill test, and isometric force production measured by a force plate. During the pre-season phase, lean mass increased significantly by ~2% for backs (testing point 1: 47 kg; testing point 2: 48 kg) and forwards (testing point 1: 50 kg; testing point 2: 51 kg) (p = ≤ 0.05). Backs significantly increased their V˙O2max by 22% from testing point 1 (40 ml kg-1 min-1) to testing point 3 (49 ml kg-1 min-1) (p = ≤ 0.04). The V˙O2max of forwards increased by 10% from testing point 1 (41 ml kg-1 min-1) to testing point 3 (45 ml kg-1 min-1), however this change was not significant (p = ≥ 0.05). Body mass (values represent the range of means across the three testing points) (backs: 68 kg; forwards: 77–78 kg), fat mass percentage (backs: 25–26%; forwards: 30–31%), resting metabolic rate (backs: 7 MJ day-1; forwards: 7 MJ day-1), isometric mid-thigh pull (backs: 2106–2180 N; forwards: 2155–2241 N), isometric bench press (backs: 799–822 N; forwards: 999–1024 N), isometric prone row (backs: 625–628 N; forwards: 667–678 N) and bloods (backs: ferritin 21–29 ug/L, haemoglobin 137–140 g/L, iron 17–21 umol/L, transferrin 3 g/L, transferring saturation 23–28%; forwards: ferritin 31–33 ug/L, haemoglobin 141–145 g/L, iron 20–23 umol/L, transferrin 3 g/L, transferrin saturation 26–31%) did not change (p = ≥ 0.05). This study provides novel longitudinal data which can be used to better prepare women rugby league players for the unique demands of their sport, underpinning female athlete health.