Lorayne Woodfield

Anthropometric and physiological characteristics of junior elite volleyball players

Objectives: To investigate the anthropometric and physiological characteristics of junior elite volleyball players. Method: Twenty five national level volleyball players (mean (SD) age 17.5 (0.5) years) were assessed on a number of physiological and anthropometric variables. Somatotype was assessed using the Heath-Carter method, body composition (% body fat, % muscle mass) was assessed using surface anthropometry, leg strength was assessed using a leg and back dynamometer, low back and hamstring flexibility was assessed using the sit and reach test, and the vertical jump was used as a measure of lower body power. Maximal oxygen uptake was predicted using the 20 m multistage fitness test. Results: Setters were more ectomorphic (p<0.05) and less mesomorphic (p<0.01) than centres. Mean (SD) of somatotype (endomorphy, mesomorphy, ectomorphy) for setters and centres was 2.6 (0.9), 1.9 (1.1), 5.3 (1.2) and 2.2 (0.8), 3.9 (1.1), 3.6 (0.7) respectively. Hitters had significantly greater low back and hamstring flexibility than opposites. Mean (SD) for sit and reach was 19.3 (8.3) cm for opposites and 37 (10.7) cm for hitters. There were no other significant differences in physiological and anthropometric variables across playing positions (all p>0.05). Conclusion: Setters tend to be endomorphic ectomorphs, hitters and opposites tend to be balanced ectomorphs, whereas centres tend to be ectomorphic mesomorphs. These results indicate the need for sports scientists and conditioning professionals to take the body type of volleyball players into account when designing individualised position specific training programmes.

Body fatness and physical activity levels of young children.

Background: The decline in physical activity levels of young children seems to be combined with a high prevalence of obesity and overweight and a reduction in the participation in organized sport. With the ever-increasing interest in exploring the relationship between physical activity and obesity amongst children, it is important to provide a more precise estimate of both physical activity and body fatness. A significant proportion of previous research on this topic has relied on self-report methods to assess physical activity and body mass index as a proxy for actual body fatness. There is a need to investigate the relationships between physical activity and fatness in children using objective methods. Aim: This study was conducted in order to explore the relationship between physical activity patterns and percentage body fat amongst a group of primary school children. Subjects and methods: Forty-seven primary school children (boys, n = 23; girls, n = 24) participated in this study. They were randomly selected from children in years 5 and 6 (9–11 year olds) of four schools drawn from the same catchment area in the city of Birmingham, UK. The frequency, intensity and duration of physical activity were determined using continuous heart rate monitoring from 8:30 am to 8:30 pm over three separate days (two weekdays and one weekend day). Percentage body fat was assessed using air displacement plethysmography. Results: Results indicated that 52% of children did not achieve a single 15-min bout of sustained moderate physical activity over the three days of monitoring. Independent t-tests revealed that girls were significantly fatter (t44 = −3.126, p = 0.003) than boys. There was no significant difference (t45 = 0.225, p > 0.05) between boys and girls in accumulated time spent with heart rates above the moderate physical activity threshold. Pearsons product moment correlation coefficients revealed no significant (r = −0.017, p > 0.05) relationship between per cent body fat and average daily time spent in moderate and vigorous activity. Conclusion: Despite the prediction to the contrary, there was no evidence of a significant relationship between percentage body fat of children and time spent in moderate and vigorous activity. Additionally, while there were no significant gender differences in physical activity patterns, children were more physically active during weekdays than weekends.

The Impact of Socio‐Economic Status on the Physical Activity Levels of British Secondary School Children

The aim of this study was to examine the physical activity levels of British secondary school children according to school year, gender and socio‐economic status. Three hundred and one children from school years 7, 8 and 9 took part in the study. Physical activity was assessed using the four by one day recall questionnaire. Results indicate that the majority of children were classified as inactive but did appear to accumulate at least 30 minutes moderate activity daily. Significant differences were evident in average daily energy expenditure (p<0.05), time spent in moderate and vigorous activity (both p<0.01), with all aspects declining with age. Males reported greater average daily energy expenditure, time spent in moderate activity and time spent in vigorous activity than females (all p<0.01). High socio‐economic status children reported greater levels of average daily energy expenditure (p<0.01) and time spent in both moderate and vigorous activity (both p<0.05). It was concluded that the physical activity levels of older children, females and children from low socio‐economic status groups may be a cause for concern.

The relationship between pedometer-determined physical activity, body mass index and lean body mass index in children

OBJECTIVE To cross-sectionally assess weekend to weekday variation of physical activity in British children and to consider the role of Body Mass Index (BMI, W/H(2)) and Lean Body Mass Index (LBMI, H(2)/W) when examining this issue. METHODS A total of 496 children aged 8-14 years, were measured for height and weight and the activity levels were analysed using pedometers to measure mean step counts for 4 consecutive days (2 weekdays, 2 weekend days). RESULTS Boys had significantly lower BMI than girls. Higher values for average weekend steps were associated with lower BMI values. BMI values were; however, found to be positively skewed but when the analysis was repeated using LBMI, data was normally distributed and the conclusions remained the same. CONCLUSIONS Weekday steps are higher than weekend steps for children irrespective of gender or weight status. Mean steps taken during weekend days are significantly associated with reduced BMI in children. These findings may be questioned because BMI is highly skewed and not normally distributed. However, LBMI provides a suitable alternative that is normally distributed and can be used to compare the relationship between weight status and physical activity.

Relationship between body image and percent body fat among British school children.

The aim of the study was to examine the relationship between body image and percent body fat in British school children. A total of 223 11- to 14-yr.-old children from central England took part in the study. Body image was measured using a self-report questionnaire, and percent body fat was measured using skinfold indices. Analysis indicated that body image and adiposity were significantly (p <.01) related for the whole sample, for boys and girls and for White children, Black children, and Asian children. An analysis of variance further indicated significant differences in body image and adiposity between boys and girls, with boys having a more positive body image and a lower percent body fat. Differences (p <.05) were also evident between Black and Asian children, with Black children having a more positive body image and lower percent body fat. No differences were evident between Black and White children or Asian and White children.

Efficacy of an integrated school curriculum pedometer intervention to enhance physical activity and to reduce weight status in children

The purpose of this study was to examine the efficacy of an integrated school curriculum pedometer intervention on children’s physical activity and weight status. Following ethics approval and informed consent, 59 children (22 boys, 27 girls, aged 10–11) from a primary school in central England completed a four-week integrated physical activity intervention based on virtually walking from John O’Groats to Lands End. Habitual physical activity and weight status (body mass index (BMI)) were determined pre- and four weeks post-intervention using pedometry. Steps/day were also calculated during the intervention period, which lasted four weeks. Results indicated that average steps/day were significantly higher (P = .0001) during and post the intervention compared to baseline. The study also found a significant main effect whereby children classified as normal weight were significantly more active than those classified as overweight/obese (P = .003). The use of a four-week integrated curriculum pedometer intervention in school is therefore feasible and results in positive outcomes in relation to daily physical activity.

Perceptions of the Built Environment in Relation to Physical Activity and Weight Status in British Adolescents from Central England

The built environment may influence physical activity (PA) behaviour in young people. However, there is a dearth of data examining this issue in young people which considers weight status, physical activity, and environmental perceptions in the same analysis. Four hundred and five Year 10 pupils (223 boys, 182 girls, mean age ±   S.D. = 14.8 ± 0.6 years), from central England, completed self-report measures of PA and perceptions of the built environment. Additionally, body mass index (BMI) was determined from height and weight. PA (MET/Min week−1) was positively related to environmental perceptions (P = 0.0001) and negatively related to BMI (P = 0.0001). PA was significantly greater in boys (P = 0.025) and normal weight children compared to girls and overweight/obese children, respectively (P = 0.01). Perception of the built environment was significant as a covariate (P = 0.0001) with a one-unit increase on this measure associated with a 141 MET/Min week−1 increase in PA. This study, therefore, supports claims that the built environment, and perceptions of it, can have an impact on health indices.

Test-retest stability of body-image scores in a sample of 12- to 14-yr.-olds.

The present study investigated test-retest variation in Body Image Questionnaire scores among a sample of British school children. 112 participants from three different school years (aged 12 to 14 years) completed the Body Image Questionnaire on two occasions separated by a 6-wk. period. No intervention designed to change, perceptions of body shape took place, hence, test-retest scores should be stable. Analysis indicated a significantly greater variation among 12- and 13-yr-olds upon retest, but not for 14-yr.-olds. Research is needed investigating factorial and test-retest stability of the measure for use with children aged 12 or under.

Evaluation of a Walking-Track Intervention to Increase Children’s Physical Activity during Primary School Break Times

Despite the known benefits of engaging in daily moderate to vigorous physical activity (MVPA), only 22% of children in England are meeting the recommended guidelines. School break times have been advocated as a key part of children’s daily routines in which their MVPA can be increased. The main aim of this study was to evaluate the effect of installing a walking-track on children’s MVPA during school break times. A mixed method design was employed which allowed for the quantitative measurement of children’s PA at three time points (baseline, mid-intervention (1–5 weeks) and follow-up (6–9 weeks)), using pedometers (n = 81, 5–9 years) and systematic observation (n = 23, 7–9 years). A semi-structured interview (n = 1) was also conducted at 10 weeks’ follow-up. The installation of the walking-track was grounded in a unique set of theoretical constructs to aid the behaviour change of the teachers. Short term positive increases in girls’ and boys’ MVPA and longer term increases in boys’ vigorous PA (VPA) were found. Qualitative data highlighted that boys dominated the walking-track and the inconsistent behaviour of school staff negatively impacted upon children’s MVPA. A set of principles to guide the installment of walking-tracks in school playgrounds are recommended.