Search

Body composition in elite rugby union athletes is routinely assessed using surface anthropometry, which can be utilized to provide estimates of absolute body composition using regression equations. This study aims to assess the ability of available skinfold equations to estimate body composition in elite rugby union athletes who have unique physique traits and divergent ethnicity. The development of sport-specific and ethnicitysensitive equations was also pursued. Forty-three male international Australian rugby union athletes of Caucasian and Polynesian descent underwent surface anthropometry and dual-energy X-ray absorptiometry (DXA) assessment. Body fat percent (BF%) was estimated using five previously developed equations and compared to DXA measures. Novel sport and ethnicity-sensitive prediction equations were developed using forward selection multiple regression analysis. Existing skinfold equations provided unsatisfactory estimates of BF% in elite rugby union athletes, with all equations demonstrating a 95% prediction interval in excess of 5%. The equations tended to underestimate BF% at low levels of adiposity, whilst overestimating BF% at higher levels of adiposity, regardless of ethnicity. The novel equations created explained a similar amount of variance to those previously developed (Caucasians 75%, Polynesians 90%). The use of skinfold equations, including the created equations, cannot be supported to estimate absolute body composition. Until a population-specific equation is established that can be validated to precisely estimate body composition, it is advocated to use a proven method, such as DXA, when absolute measures of lean and fat mass are desired, and raw anthropometry data routinely to derive an estimate of body composition change. [ABSTRACT FROM AUTHOR]

Reports detailing the physiques of open-water (OW) swimmers are limited. Data from anthropometric screening around competition provides a unique opportunity to describe the current physical attributes of elite OW swimmers peaking for international competition. Anthropometric screening was undertaken on a group of Australian and French OW swimmers as part of performance monitoring within 2 wk of the 2015 FINA World Championships. Height, mass, and sum of 7 skinfolds were measured using ISAK standardized measurement techniques by 2 trained anthropometrists. Data were collated and compared with previously published data on OW and pool swimmers. French swimmers had lower skinfolds (57.3 ± 6.1 vs 80.5 ± 21.3 mm, P = .0258), were lighter (64.7 ± 10.8 vs 74.6 ± 11.8 kg, P = .013), and had lower lean-mass index (LMI) (34.7 ± 7.3 vs 38.2 ± 8.8, P = .035) than Australian swimmers. Male and female OW swimmers had skinfolds similar to their contemporary OW swimmers but were lower than earlier reports of OW swimmers; however, they were higher than those of pool swimmers. Male and female OW swimmers had 9% and 6% lower LMI, respectively, than pool swimmers. Lower body mass and LMI were correlated with better World Championships finishing positions (R²= .46, P = .0151, and R²= .45, P = .0177, respectively). These data are a unique report of elite OW swimmers' physiques around international competition and demonstrate a potential morphological optimization in OW swimmers that warrants further investigation in larger populations. [ABSTRACT FROM AUTHOR]

Purpose: To examine the effect of body mass (BM) on eccentric knee-flexor strength using the Nordbord and offer simple guidelines to control for the effect of BM on knee-flexor strength. Methods: Data from 81 soccer players (U17, U19, U21, senior 4th French division, and professionals) and 41 Australian Football League (AFL) players were used for analysis. They all performed 1 set of 3 maximal repetitions of the bilateral Nordic hamstring exercise, with the greatest strength measure used for analysis. The main regression equation obtained from the overall sample was used to predict eccentric knee-flexor strength from a given BM (moderate TEE, 22%). Individual deviations from the BM-predicted score were used as a BM-free index of eccentric knee-flexor strength. Results: There was a large (r = .55, 90% confidence limits .42;.64) correlation between eccentric knee-flexor strength and BM. Heavier and older players (professionals, 4th French division, and AFL) outperformed their lighter and younger (U17-U21) counterparts, with the soccer professionals presenting the highest absolute strength. Professional soccer players were the only ones to show strength values likely slightly greater than those expected for their BM. Conclusions: Eccentric knee-flexor strength, as assessed with the Nordbord, is largely BM-dependent. To control for this effect, practitioners may compare actual test performances with the expected strength for a given BM, using the following predictive equation: Eccentric strength (N) = 4 x BM (kg) + 26.1. Professional soccer players with specific knee-flexor-training history and enhanced neuromuscular performance may show higher than expected values. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the physical qualities that differentiate playing minutes in international-level women's rugby sevens players. Methods: Twenty-four national-level female rugby sevens players underwent measurements of anthropometry, acceleration, speed, lower- and upper-body strength, lower-body power, and aerobic fitness. Playing minutes in international competition were used to differentiate players into 2 groups, a high- or low-playing-minutes group. Playing minutes were related to team selection, which was determined by the coaching staff. Playing minutes were therefore used to differentiate performance levels. Results: Players in the high-playing-minutes group (>70 min) were older (mean ± SD 24.3 ± 3.1 vs 21.2 ± 4.3 y, P = .05, effect size [ES] = 0.77 ± 0.66, 90% confidence limit) and had greater experience in a national-training-center environment (2.4 ± 0.8 vs 1.7 ± 0.9 y, P = .03, ES = 0.83 ± 0.65), faster 1600-m time (374.5 ± 20.4 vs 393.5 ± 29.8 s, P = .09, ES = -0.70 ± 0.68), and greater 1-repetition-maximum upper-body strength (bench press 68.4 ± 6.3 vs 62.2 ± 8.1 kg, P = .07, ES = 0.80 ± 0.70, and neutral-grip pull-up 84.0 ± 8.2 vs 79.1 ± 5.4 kg, P = .12, ES = 0.68 ± 0.72) than athletes who played fewer minutes. Age (rs = .59 ± ~.28), training experience (rs = .57 ± ~.29), bench press (r = .44 ± ~.36), and 1600-m time (r = -.43 ± ~.34) were significantly associated with playing minutes. Neutral-grip pull-up and bench press contributed significantly to a discriminant analysis. The average squared canonical correlation was .46. The discriminant analysis predicted 7 of 9 and 6 of 10 high- and low-playing-minutes athletes, respectively. Conclusions: Age, training experience, upper-body strength, and aerobic fitness differentiated athlete playing minutes in international women's rugby sevens. [ABSTRACT FROM AUTHOR]

This study aimed to profile the physiological characteristics of junior sprint kayak athletes (n = 21, VO2max 4.1 ± 0.7 L/min, training experience 2.7 ± 1.2 y) and to establish the relationship between physiological variables (VO2max, VO2 kinetics, muscleoxygen kinetics, paddling efficiency) and sprint kayak performance. VO2max, power at VO2max, power:weight ratio, paddling efficiency, VO2 at lactate threshold, and whole-body and muscle oxygen kinetics were determined on a kayak ergometer in the laboratory. Separately, on-water time trials (TT) were completed over 200 m and 1000 m. Large to nearly perfect (-.5 to -.9) inverse relationships were found between the physiological variables and on-water TT performance across both distances. Paddling efficiency and lactate threshold shared moderate to very large correlations (-.4 to -.7) with 200- and 1000-m performance. In addition, trivial to large correlations (-.11 to -.5) were observed between muscle-oxygenation parameters, muscle and whole-body oxygen kinetics, and performance. Multiple regression showed that 88% of the unadjusted variance for the 200-m TT performance was explained by VO2max, peripheral muscle deoxygenation, and maximal aerobic power (P < .001), whereas 85% of the unadjusted variance in 1000-m TT performance was explained by VO2max and deoxyhemoglobin (P < .001). The current findings show that well-trained junior sprint kayak athletes possess a high level of relative aerobic fitness and highlight the importance of the peripheral muscle metabolism for sprint kayak performance, particularly in 200-m races, where finalists and nonfinalists are separated by very small margins. Such data highlight the relative aerobic-fitness variables that can be used as benchmarks for talent-identification programs or monitoring longitudinal athlete development. However, such approaches need further investigation. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the relationship between selected physical capacities and repeated-sprint performance of Australian Football League (AFL) players and to determine which physical capacities contributed to being selected for the first competition game. Methods: Sum of skinfolds, 40-m sprint (with 10-, 20-, 30-, and 40-m splits), repeated-sprint ability (6 x 30-m sprints), and 3-km-run time were measured during the preseason in 20 AFL players. The physical qualities of players selected to play the first match of the season and those not selected were compared. Pearson correlation coefficients were used to determine the relationship among variables, and a regression analysis identified variables significantly related to repeated-sprint performance. Results: In the regression analysis, maximum velocity was the best predictor of repeated-sprint time, with 3-km-run time also contributing significantly to the predictive model. Sum of skinfolds was significantly correlated with 10-m (r = .61, P< .01) and 30-m(r= .53, P< .05) sprint times. A 2.6% ± 2.1 % difference in repeated-sprint time (P < .05, ES = 0.88 ± 0.72) was observed between those selected (25.26 ± 0.55 s) and not selected (25.82 ± 0.80 s) for the first game of the season. Conclusions: The findings indicate that maximum-velocity training using intervals of 30-40 m may contribute more to improving repeated-sprint performance in AFL players than short 10- to 20-m intervals from standing starts. Further research is warranted to establish the relative importance of endurance training for improving repeated-sprint performance in AFL football. [ABSTRACT FROM AUTHOR]

Purpose: Little research has been done on the physiological and performance effects of altitude training on team-sport athletes. Therefore, this study examined changes in 2000-m time-trial running performance (TT), hemoglobin mass (Hbmass), and intramuscular carnosine content of elite Australian Football (AF) players after a preseason altitude camp. Methods: Thirty elite AF players completed 19 days of living and training at either moderate altitude (-2130 m; ALT, n = 21 ) or sea level (CON, n = 9). TT performance and Hbmass were assessed preintervention (PRE) and postintervention (POST1) in both groups and at 4 wk after returning to sea level (POST2) in ALT only. Results: Improvement in TT performance after altitude was likely 1.5% (± 4.8-90%CL) greater in ALT than in CON, with an individual responsiveness of 0.8%. Improvements in TT were maintained at POST2 in ALT. Hbmassafter altitude was very likely increased in ALT compared with CON (2.8% ± 3.5%), with an individual responsiveness of 1.3%. Hbmass returned to baseline at POST2. Intramuscular carnosine did not change in either gastrocnemius or soleus from PRE to POST1. Conclusions: A preseason altitude camp improved TT performance and Hbmass in elite AF players to a magnitude similar to that demonstrated by elite endurance athletes undertaking altitude training. The individual responsiveness of both TT and Hbmasswas approximately half the group mean effect, indicating that most players gained benefit. The maintenance of running performance for 4 wk, despite Hbmass returning to baseline, suggests that altitude training is a valuable preparation for AF players leading into the competitive season. [ABSTRACT FROM AUTHOR]

Body composition can substantially impact elite swimming performance. In practice, changes in fat and lean mass of elite swimmers are estimated using body mass, sum of seven skinfolds (∑7) and lean mass index (LMI). However, LMI may be insufficiently accurate to detect small changes in body composition which could meaningfully impact swimming performance. This study developed equations which estimate dual-energy x-ray absorptiometry (DXA)-derived lean and fat mass using body mass and ∑7 data. Elite Australian swimmers (n = 44; 18 male, 26 female) completed a DXA scan and standardised body mass and ∑7 measurements. Equations to estimate DXA-derived lean and fat mass based on body mass, ∑7 and sex were developed. The relationships between ∑7, body mass and DXA-derived lean and fat mass were non-linear. Fat mass (Adjusted R2 = 0.91; standard error = 1.0 kg) and lean mass (Adjusted R2 = 0.99; standard error = 1.0 kg) equations were considered sufficiently accurate. Lean mass estimates outperformed the LMI in identifying the correct direction of change in lean mass (82% correct; LMI 71%). Using the accurate estimations produced by these equations will enhance the prescription and evaluation of programmes to optimise the body composition and subsequent performance in swimmers. [ABSTRACT FROM AUTHOR]

Although the characteristics of 15-a-side rugby union players have been well defined, there is little information on rugby sevens players. Purpose: The authors profiled the anthropometric, physiological, and performance qualities of elite-level rugby sevens players and quantified relationships between these characteristics. Methods: Eighteen male international rugby sevens players undertook anthropometric (body mass, height, sum of 7 skinfolds, lean-mass index), acceleration and speed (40-m sprint), muscle-power (vertical jump), repeated- sprint-ability (6 x 30-m sprint), and endurance (Yo-Yo Intermittent Recovery test and treadmill VO2max) testing. Associations between measurements were assessed by correlation analysis. Results: Rugby sevens players had anthropometric characteristics (body mass 89.7 ± 7.6 kg, height 1.83 ± 0.06 m, sum of 7 skinfolds 52.2 ± 11.5 mm; mean ± SD) similar to those of backs in international 15-player rugby union. Acceleration and speed (40-m sprint 5.11 ±0.15 s), muscle-power (vertical jump 66 ± 7 cm), and endurance (VO2max 53.8 ± 3.4 mL ¦ kg^1 ¦ min"1) qualities were similar to, or better than, those of professional 15-a-side players. Coefficients of variation ranged from 2.5% to 22%. Relative VO2max was largely correlated with Yo-Yo distance (r = .60, .21-.82; 90% confidence interval) and moderately correlated with 40-m sprint time (r = -.46, -.75 to-.02) and repeated-sprint ability (r - -.38, -.72 to .09). Conclusions: International rugby sevens players require highly developed speed, power, and endurance to tolerate the demands of competition. The small between-athletes variability of characteristics in rugby sevens players highlights the need for relatively uniform physical and performance standards in contrast with 15-a-side players. [ABSTRACT FROM AUTHOR]

Purpose: The main purpose of the present study was to quantify the match running demands and physiological intensities of AF field and boundary umpires during match play. Methods: Thirty-five AF umpires [20 field (age: 24.7 ± 7.7 y, body mass: 74.3 ± 7.1 kg, ∑7 skinfolds: 67.8 ± 18.8 mm); 15 boundary (age: 29.6 ± 13.6 y, body mass: 71.9 ± 3.1 kg, ∑7 skinfolds: 65.6 ± 8.8 mm)] volunteered to participate in the study. Movement characteristics [total distance (TD), average running speed, high-intensity activity (HIA; >14.4 km·h-1) distance] and physiological measures [heart rate, blood lactate concentration ([BLa−]), and rating of perceived exertion] were collected during 20 state-based AF matches. Results: The mean (± SD) TD covered by field umpires was 11,492 ± 1,729 m, with boundary umpires covering 15,061 ± 1,749 m. The average running speed in field umpires was 103 ± 14 m·min-1, and was 134 ± 14 m·min-1 in boundary umpires. Field and boundary umpires covered 3,095 ± 752 m and 5,875 ± 1,590 m, during HIA, respectively. In the first quarter, HIA distance (field: P = .004, η2 = 0.071, boundary: P < .001, η2 = 0.180) and average running speed (field: P = .002, η2 = 0.078, boundary: P < .001, η2 = 0.191) were significantly greater than in subsequent quarters. Conclusions: The results demonstrate that both AF field and boundary umpires complete similar running demands to elite AF players and are subject to physical fatigue. Further research is warranted to see if this physical fatigue impacts on the cognitive function of AF umpires during match play. [ABSTRACT FROM AUTHOR]

Objective: To describe the associations between body composition and hormonal and inflammatory factors measured 5 years prior and tibial cartilage volume in young adults, and to explore if these factors contribute to the sex difference in tibial cartilage volume.Methods: Subjects broadly representative of the young adult Australian population (n = 328, ages 31-41 years, 47.3% women) were selected. They underwent T1-weighted fat-suppressed magnetic resonance imaging (MRI) of their knees. Tibial cartilage volume was measured from MRI. Sex hormone binding globulin (SHBG) and testosterone in a subset of women and C-reactive protein (CRP) level and fibrinogen in both sexes were measured 5 years prior. Body mass index (BMI), fat mass, and lean mass were calculated from height, weight, and skinfolds.Results: In multivariable analyses, correlates of tibial cartilage volume included lean body mass (β = 26.4 mm(3) ; 95% confidence interval [95% CI] 13.6, 39.1), fat mass (β = -11.8 mm(3) ; 95% CI -22.2, -1.4), and fibrinogen (β = -146.4 mm(3) ; 95% CI -276.4, -16.4), but not BMI, testosterone, or CRP level. In women, SHBG was positively associated with tibial cartilage volume (β = 0.67 mm(3) ; 95% CI 0.14, 1.20) and Free Androgen Index was negatively associated with lateral tibial cartilage volume (β = -0.04 mm(3) ; 95% CI -0.07, 0.00). Men had 13% more tibial cartilage volume (500 mm(3) ) than women. The magnitude of this association decreased by 38%, 20%, and 37% after adjustment for lean body mass, fat mass, and fibrinogen, respectively.Conclusion: Body composition, sex hormones, and fibrinogen correlate with knee cartilage volume in young adult life. Sex difference in knee cartilage volume is contributed largely by variations in body composition and/or fibrinogen. [ABSTRACT FROM AUTHOR]

This study describes the body composition traits of modern-day elite rugby union athletes according to playing position and ethnicity. Thirty-seven international Australian rugby athletes of Caucasian and Polynesian descent undertook body composition assessment using dual-energy X-ray absorptiometry and surface anthropometry. Forwards were significantly taller, heavier and had a greater total fat mass and lean mass than backs. Backs displayed a higher percentage lean mass and lower sum of seven skinfolds and percentage fat mass. While no whole body composition differences were seen between ethnicities, significant regional differences were observed. In the periphery (arm and leg) regions, Polynesians had a greater proportion of fat mass (53.1% vs. 51.3%,P = 0.052,d = 0.5) and lean mass (49.7% vs. 48.6%,P = 0.040,d = 0.9), while in the trunk region a lower proportion of fat mass (37.2% vs. 39.5%,P = 0.019,d = 0.7) and lean mass (45.6% vs. 46.8%,P = 0.020,d = 1.1). Significant differences were also seen between Caucasian and Polynesian forwards in leg lean mass (31.4 kg vs. 35.9 kg,P = 0.014,d = 2.4) and periphery lean mass (43.8 kg vs. 49.6 kg,P = 0.022,d = 2.4). Elite Polynesian rugby athletes have different distribution patterns of fat mass and lean mass compared to Caucasians, which may influence their suitability for particular positions. [ABSTRACT FROM AUTHOR]

The article discusses research which investigated the relationship between physical performance and match performance in Australian Rules Football. Researchers evaluated the performance of 36 semiprofessional players. They found that the three kilometer time trial performance was a predictor of direct game involvement per minute and that playing experience was related to match performance.

This study determined the precision of pencil and fan beam dual-energy X-ray absorptiometry (DXA) devices for assessing body composition in professional Australian Football players. Thirty-six professional Australian Football players, in two groups (fan DXA,N = 22; pencil DXA,N = 25), underwent two consecutive DXA scans. A whole body phantom with known values for fat mass, bone mineral content and fat-free soft tissue mass was also used to validate each DXA device. Additionally, the criterion phantom was scanned 20 times by each DXA to assess reliability. Test–retest reliability of DXA anthropometric measures were derived from repeated fan and pencil DXA scans. Fat-free soft tissue mass and bone mineral content from both DXA units showed strong correlations with, and trivial differences to, the criterion phantom values. Fat mass from both DXA showed moderate correlations with criterion measures (pencil:r = 0.64; fan:r = 0.67) and moderate differences with the criterion value. The limits of agreement were similar for both fan beam DXA and pencil beam DXA (fan: fat-free soft tissue mass = −1650 ± 179 g, fat mass = −357 ± 316 g, bone mineral content = 289 ± 122 g; pencil: fat-free soft tissue mass = −1701 ± 257 g, fat mass = −359 ± 326 g, bone mineral content = 177 ± 117 g). DXA also showed excellent precision for bone mineral content (coefficient of variation (%CV) fan = 0.6%; pencil = 1.5%) and fat-free soft tissue mass (%CV fan = 0.3%; pencil = 0.5%) and acceptable reliability for fat measures (%CV fan: fat mass = 2.5%, percent body fat = 2.5%; pencil: fat mass = 5.9%, percent body fat = 5.7%). Both DXA provide precise measures of fat-free soft tissue mass and bone mineral content in lean Australian Football players. DXA-derived fat-free soft tissue mass and bone mineral content are suitable for assessing body composition in lean team sport athletes. [ABSTRACT FROM AUTHOR]

Background: Low birth weight has been consistently associated with adult chronic disease risk. The thrifty phenotype hypothesis assumes that reduced fetal growth impacts some organs more than others. However, it remains unclear how birth weight relates to different body components, such as circumferences, adiposity, body segment lengths and limb proportions. We hypothesized that these components vary in their relationship to birth weight. Methods: We analysed the relationship between birth weight and detailed anthropometry in 1270 singleton live-born neonates (668 male) from the Mater-University of Queensland Study of Pregnancy (Brisbane, Australia). We tested adjusted anthropometry for correlations with birth weight. We then performed stepwise multiple regression on birth weight of: body lengths, breadths and circumferences; relative limb to neck-rump proportions; or skinfold thicknesses. All analyses were adjusted for sex and gestational age, and used logged data. Results: Circumferences, especially chest, were most strongly related to birth weight, while segment lengths (neck-rump, thigh, upper arm, and especially lower arm and lower leg) were relatively weakly related to birth weight, and limb lengths relative to neck-rump length showed no relationship. Skinfolds accounted for 36% of birth weight variance, but adjusting for size (neck-rump, thigh and upper arm lengths, and head circumference), this decreased to 10%. There was no evidence that heavier babies had proportionally thicker skinfolds. Conclusions: Neonatal body measurements vary in their association with birth weight: head and chest circumferences showed the strongest associations while limb segment lengths did not relate strongly to birth weight. After adjusting for body size, subcutaneous fatness accounted for a smaller proportion of birth weight variance than previously reported. While heavier babies had absolutely thicker skinfolds, this was proportional to their size. Relative limb to trunk length was unrelated to birth weight, suggesting that limb proportions at birth do not index factors relevant to prenatal life. [ABSTRACT FROM AUTHOR]

This study explored the influence of physical and cognitive measures on reactive agility performance in basketball players. Twelve men basketball players performed multiple sprint, Change of Direction Speed Test, and Reactive Agility Test trials. Pearson’s correlation analyses were used to determine relationships between the predictor variables (stature, mass, body composition, 5-m, 10-m and 20-m sprint times, peak speed, closed-skill agility time, response time and decision-making time) and reactive agility time (response variable). Simple and stepwise regression analyses determined the individual influence of each predictor variable and the best predictor model for reactive agility time. Morphological (r = –0.45 to 0.19), sprint (r = –0.40 to 0.41) and change-of-direction speed measures (r = 0.43) had small to moderate correlations with reactive agility time. Response time (r = 0.76,P = 0.004) and decision-making time (r = 0.58,P = 0.049) had large to very large relationships with reactive agility time. Response time was identified as the sole predictor variable for reactive agility time in the stepwise model (R2 = 0.58,P = 0.004). In conclusion, cognitive measures had the greatest influence on reactive agility performance in men basketball players. These findings suggest reaction and decision-making drills should be incorporated in basketball training programmes. [ABSTRACT FROM AUTHOR]

Research is presented which examined methods for quantifying training in Sprint Kayak and monitoring the fitness and performance of 10 junior Sprint Kayak athletes with a focus on the session rating of perceived exertion (session-RPE) method and common measures of training load (TL). The study found that session-RPE is a valid method for monitoring TL for junior Sprint Kayak athletes and also supports the use of session-RPE in Sprint Kayak training.

The article reports on research which was conducted to investigate the potential association with anthropometry and upper-body pulling strength with sprint kinematics of competitive surfers. Researchers evaluated 10 competitive male surfers. They found that there was a strong association between relative upper-body pulling strength and sprint paddling ability in surfers and concluded that coaches working with competitive surfers should implement strength training with the surfers.

The article discusses research investigating the magnitude of changes in upper and lower body strength in highly trained professional rugby union players following two years of training. The study's experimental design and the authors' conclusion regarding the influence of starting strength level, lean mass index (LMI), and chronological age on the level of strength changes are presented.

The article reports on research which was conducted to examine the anthropometric, vertical jump, and strength quality changes over two years in a group of national team volleyball players. Researchers evaluated 14 players. After evaluating the players for two years researchers concluded that elite male volleyball players can improve leanness and power, which contribute to improvements in vertical jump.

The article presents the results of a study which investigated the effectiveness of the basketball simulation test to measure athletic performance. An overview of related previous research is provided, detailing the use of field tests to measure various aspects of player performance. Details of the experiment protocol are also presented, including interval use of the Yo-Yo Intermittent Recovery Test and heart rate monitoring.

Summary: To evaluate the utility of fitness assessment and trends in drafting of players in the Australian Football League, we analysed height, mass, skinfolds, 20-m sprint, vertical jump, agility run and endurance assessed in the 495 players attending the annual national draft camps between 1999 and 2004. Effects of player position and assessment year were expressed as standardised mean differences (Cohen effect sizes) and interpreted qualitatively. Effect of birth month on chance of being drafted, which may be important in team sports, was also analysed. Compared with midfield players, ruckmen, tall forwards and tall defenders were decisively taller (effect-size range 1.33–1.95, large) and heavier (1.30–1.63, large), but had poorer sprint speed (0.23–0.57, small), aerobic ability (0.66–1.18, moderate) and agility (0.64–1.11, moderate). The only substantial changes in fitness scores over the 5-year period were an increase in height (0.76, moderate) and an increase in 20-m sprint time (0.39, small). A majority (65%) of players attending the camps were born in the first half of a given year, but their chance of being drafted (70%) was similar to that of players born in the second half (64%). We conclude that fitness assessment is useful for differentiating between player positions and identifying some annual trends in recruitment in Australian football, and that players with a second half birth month have been disadvantaged with lower representation at the national draft camp. [Copyright &y& Elsevier]

Background: Nuclear magnetic resonance (NMR) metabolic profiling quantifies a large number of metabolites. From adolescence, specific metabolites are influenced by age, sex and body mass index; data on early-life metabolic profiles are limited. We investigated associations between sex, birth weight, weight and adiposity with NMR metabolic profile at age 12 months., Methods: The plasma NMR metabolic profile was quantified in infants (n = 485) from the Barwon Infant Study. Associations between 74 metabolites and sex, birth weight z-score and 12-month measures (weight z-score, skinfold thickness, weight-for-length z-score) were examined using linear regression models., Results: Several cholesterol and fatty acid measures were higher (0.2-0.3 SD) in girls than in boys; we observed modest sex-specific associations of birth weight z-scores and 12-month sum of skinfold thicknesses with metabolites. The pattern of associations between weight z-score and weight-for-length z-score with metabolites at 12 months was more pronounced in girls, particularly for fatty acid ratios., Conclusions: We identified sex differences in the infant metabolic profile. Sex-specific patterns observed differ from those reported in older children and adults. We also identified modest cross-sectional associations between anthropometric and adiposity measures and metabolites, some of which were sex specific.

Background and Objectives: This study validated the Malnutrition Universal Screening Tool (MUST) for nutritional screening in acutely unwell elderly patients against a reference assessment tool - Patient-Generated Subjective Global Assessment (PG-SGA)., Methods and Study Design: One hundred and thirty two acutely admitted general medical patients contributed data for this study. In addition to performance of MUST and PG-SGA the following nutritional parameters were measured: weight loss >5% in previous 3-6 months, handgrip strength, triceps skinfold thickness, Mid-arm circumference, Mid-arm muscle circumference (MAMC). Quality of life (QoL) was determined using the EuroQoL Questionnaire (EQ-5D 5 level). Sensitivity, specificity, predictive values and concordance were calculated to validate MUST against PG-SGA., Results: MUST when compared to PG-SGA gave a sensitivity of 69.7%, specificity of 75.8%, positive predictive value of 75.4%, negative predictive value of 70.1% and kappa statistics showed 72.7% agreement (k=0.49) for detecting malnutrition. The MUST score had significant inverse correlation with body mass index, Triceps skinfold thickness and Mid-arm muscle circumference but not with Handgrip strength. Malnourished patients (PG-SGA class B/C) were found to have a significantly worse QoL., Conclusions: This study demonstrates that MUST can be confidently administered with respect to validity in acutely unwell general medical elderly patients to detect malnutrition. In this study, significant recent weight loss also seems to have validity, almost comparable to MUST, for predicting the risk of malnutrition. Further research is needed to verify this finding, as a single item may be more feasible to complete than an instrument consisting of two or more items.

Purpose: To determine whether a previously validated performance-testing protocol for competitive surfers is able to differentiate between Australian elite junior surfers selected (S) to the national team and those not selected (NS)., Methods: Thirty-two elite male competitive junior surfers were divided into 2 groups (S=16, NS=16). Their age, height, body mass, sum of 7 skinfolds, and lean-body-mass ratio (mean±SD) were 16.17±1.26 y, 173.40±5.30 cm, 62.35±7.40 kg, 41.74±10.82 mm, 1.54±0.35 for the S athletes and 16.13±1.02 y, 170.56±6.6 cm, 61.46±10.10 kg, 49.25±13.04 mm, 1.31±0.30 for the NS athletes. Power (countermovement jump [CMJ]), strength (isometric midthigh pull), 15-m sprint paddling, and 400-m endurance paddling were measured., Results: There were significant (P≤.05) differences between the S and NS athletes for relative vertical-jump peak force (P=.01, d=0.9); CMJ height (P=.01, d=0.9); time to 5-, 10-, and 15-m sprint paddle; sprint paddle peak velocity (P=.03, d=0.8; PV); time to 400 m (P=.04, d=0.7); and endurance paddling velocity (P=.05, d=0.7)., Conclusions: All performance variables, particularly CMJ height; time to 5-, 10-, and 15-m sprint paddle; sprint paddle PV; time to 400 m; and endurance paddling velocity, can effectively discriminate between S and NS competitive surfers, and this may be important for athlete profiling and training-program design.

Purpose: The aim of the current study was to quantify the physiological, psychometric, and performance effects of a 2-wk Christmas break in a professional Australian Football League club., Methods: A series of physiological (eg, heart-rate [HR] response to a 5-min submaximal run and skinfold thicknesses), psychometric (rating-of-perceived-exertion [RPE] responses and wellness variables), and performance (running activity during standardized handball games, isometric midthigh pull [IMTP] peak force, and countermovement jump [CMJ]) measures were conducted in the weeks before and after the break., Results: There was a possible and small increase in the sum of 7 skinfolds, while body mass and fat-free mass remained possible and likely unchanged, respectively. Sleep and stress scores remained likely to almost certainly unchanged, but there were some small, possible to likely decreases in fatigue and soreness scores. HR and RPE responses to the 5-min submaximal run were likely slightly lower (ie, improved) after the break. High-intensity running and acceleration distance during a standard handball game were very likely slightly greater, while HR and RPE responses to the game were possibly to very likely unchanged. HR responses to a high-intensity training session remained very likely unchanged. There was also a likely small increase in IMTP peak force but likely to very likely no change in CMJ variables., Conclusions: The results show that players returned from a 2-wk break during preseason well recovered, with preserved to improved levels of strength and cardiorespiratory fitness, despite small increases in skinfold thickness.

Objectives: To determine if upper-body strength or power changes during the competitive season for elite Australian rules footballers and what influence the number of training years has on any changes., Design: Repeated measures., Methods: Twenty elite Australian rules footballers were assessed at preseason, in-season and postseason. Strength was assessed by the 1 Repetition Maximum bench press and power was assessed by bench press throws. Athletes' results were analysed as a whole group as well as being divided into two groups according to training years: less than 3 years training and greater than 3 years training. All athletes performed the same resistance training program., Results: There were no significant differences in height, body mass, or skinfold measurements between the two age groups. As a whole group, there was no significant change in 1RM bench press. There was a small but significant decrease in mean bench throw power in-season (525 W) compared to preseason (542 W) and it then increased at postseason (541 W). Within group analysis revealed the in-season decrease in upper-body power was largely pertaining to the younger athletes. The older group maintained their upper body power levels while the younger group decreased power in-season (4%) before regaining it at season's end., Conclusion: Older footballers were able to maintain their upper body power while the younger footballers had a small but significant decrease in-season before regaining it by season's end. The overall volume of training and playing appears to have affected the younger athletes' power more than older athletes. Both age groups maintained upper body strength., (Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Objective: The waist-to-height ratio (WHtR) assesses abdominal adiposity and has been proposed to be of greater value in predicting obesity-related cardiovascular health risks in children than BMI. The present study aims to develop WHtR cut-offs for overweight and obesity based on the 85th and 95th percentiles for the percentage body fat (%BF) in a cohort of children and adolescents., Design: Waist circumference (WC), height, triceps and subscapular skinfolds were used to calculate WHtR and %BF. Correlations between WHtR and %BF and WHtR/mid-abdominal skinfold were made. Receiver-operating characteristic (ROC) curve analysis was used to select WHtR cut-offs to define overweight and obesity. Subjects were grouped by WHtR cut-offs, and mean values for anthropometry, blood lipids and blood pressure (BP) variables were compared., Setting: Australian primary and secondary schools., Subjects: A total of 2773 male (M) and female (F) subjects of the 1985 Australian Health and Fitness Survey, aged 8-16 years., Results: Correlation coefficients between WHtR and %BF were M: r = 0.73, F: r = 0.60, P < 0.01 and WHtR/mid-abdominal skinfold were M: r = 0.78, F: r = 0.65, P < 0.01. WHtR of 0.46(M) and 0.45(F) best identified subjects with > or = 85th percentile for %BF and 0.48(M) and 0.47(F) identified subjects with > or = 95th percentile for %BF. When comparing the highest WHtR group to the lowest, both sexes had significantly higher means for weight, WC, %BF, TG (male subjects only), systolic BP (female subjects only) and lower means for HDL cholesterol (P < 0.05)., Conclusions: WHtR is useful in clinical and population health as it identifies children with higher %BF at greater risk of developing weight-related CVD at an earlier age.

We explore relationships between BMI and skinfolds and anthropometric variables reflecting variation in lean body frame. Data on the middle class adult Australian women (n = 1260) collected in 2002 during a National Body Size and Shape Survey were used. Standard measurements of stature, weight, skeletal dimensions (shoulder width, hip width, chest width, and depth, limb lengths), circumferences of head, trunk, limbs and triceps, subscapular and abdominal skinfolds were taken. Techniques for measurements of skeletal frame minimized the inclusion of adipose tissue thickness. Analysis of variance and parametric and nonparametric correlations were used. Vertical dimensions show weak correlations with fatness, while body frame circumferences and transverse dimensions are consistently, significantly, and substantially correlated with fatness, each explaining from 3 to 44% of variation in skinfold thickness. Skeletal dimensions explain up to 50% of variation in skinfold thickness (multiple regression). Especially high correlations with skinfold thickness occur for chest width, depth, and hip width (r range from 0.42 to 0.66). Body frame dimensions reflect largely trunk volume and the trunk/limb proportions. Larger lean trunk size is associated with greater fatness. Since the size of the abdominal cavity, and thus the gastrointestinal system (GI), is reflected in the trunk size, we speculate that larger frame may predispose to obesity in two ways: (1) larger stomachs require greater bulk of food to produce feeling of satiety as mediated through antral distension, (2) larger GIs may absorb more nutrients. Frame size may help to detect the risk of obesity among young adults., (2009 Wiley-Liss, Inc.)

The purpose of this study was to investigate the anthropometric and fitness characteristics of elite female water polo players and examine the differences between players of different competition levels (national and international) and playing positions (center and perimeter). Twenty-six female water polo players (National League, n = 12, and National Squad, n = 14) underwent measurements of standard anthropometry (height, body mass, and sum of 7 skinfolds), lower-body muscular power (in-water vertical jump), speed (10-m maximal sprint swim), and aerobic fitness (multistage shuttle swim test). No goalkeepers were involved. The National Squad players were taller (173.7 +/- 5.5 vs. 169.6 +/- 4.4 cm; p < 0.05) and heavier (74.6 +/- 8.0 vs. 65.8 +/- 8.4 kg; p < 0.05) and had better jumping (139.0 +/- 7.0 vs. 129.7 +/- 4.6 cm; p < 0.001), sprinting (5.96 +/- 0.21 vs. 6.26 +/- 0.34 seconds; p < 0.05), and endurance swimming abilities (652 +/- 84 vs. 449 +/- 124 m; p < 0.001) compared with the National League players. Perimeter players had lower-body mass (70.2 +/- 3.8 vs. 82.5 +/- 7.4 kg; p < 0.001) and skinfold levels (88.7 +/- 14.1 vs. 118.6 +/- 22.2 mm; p < 0.01) and better sprinting (5.88 +/- 0.19 vs. 6.10 +/- 0.19 seconds; effect size [ES] = 1.16, p > 0.05) and endurance swimming abilities (678 +/- 65 vs. 606 +/- 102 m; ES = 0.84, p > 0.05) compared with center players. These findings demonstrate that anthropometric and fitness characteristics can discriminate between players of different competition levels and playing positions. These water polo-specific field tests may assist coaches in profiling players and evaluating adaptations to training.

Objective: To describe the prevalence and clinical characteristics of the metabolic syndrome (MetS) in a cohort of Australian Aboriginal children., Study Design: Body mass index (BMI), waist circumference, skin fold thickness, body fat percentage, insulin resistance, and the prevalence of MetS were evaluated in 486 children age 9 to 14 years from the Darwin Health Region, Northern Territory, Australia., Results: Using an age- and sex- specific definition, 14% of the children in the cohort had MetS, 6.4% were overweight, 4.9% were obese, and 26.2% had an elevated waist circumference. The mean percentage of body fat was 30.2%. The children with MetS had higher BMI and waist z-scores, percent body fat, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) score, and skin fold thickness compared with those without MetS (P < .001); however, >50% of those with MetS were neither overweight nor obese. Waist circumference was significantly associated with insulin resistance as measured by the HOMA-IR (P < .001)., Conclusions: MetS is common in our cohort despite low rates of overweight and obesity. A tendency for central adiposity is already evident in these young children. Measurement of waist circumference may help identify Aboriginal children at high risk for MetS.

The total amount and location of fat deposition are important factors in the development of obesity and the metabolic syndrome. To date there have been no reported studies of ethnic and gender differences in body composition and fat distribution patterns in Japanese and Australian young adults. The aim of this study was to assess body composition of young Japanese and Australian Caucasian adults using whole-body dual energy x-ray absorptiometry (DXA) and anthropometry to examine body fat deposition patterns. Body composition of 45 Japanese males and 42 Australian Caucasian males living in Australia (aged 18-40 years) and 139 Japanese females living in Japan (aged 18-27 years) were measured using whole-body DXA scanning and anthropometry. Differences in relationships between BMI and waist circumference (WC), sum of skinfolds (SigmaSF) and %BF obtained from DXA were assessed using multivariate analyses. Distinct gender and ethnic differences (p<0.05) in bone density and waist circumference were observed but no gender differences in BMI and bone mineral content and no ethnic differences in sum of skinfolds and %BF. Both Japanese males and females showed a greater %BF at given BMI, WC and SigmaSF values (p<0.05). The results indicate differences in relationships between %BF and anthropometric measures in young Japanese compared to Caucasians and the importance of population-specific cut-off points for these indices. These findings also have implications for the development of chronic disease and further research, including studies in other Asian countries, is recommended.

This cross-sectional study aimed to determine ethnic and environmental influences on the relationship between BMI and percentage body fat, using a sample of 144 Japanese and 140 Australian-Caucasian men living in Australia, and eighty-eight Japanese men living in Japan. Body composition was assessed by anthropometry using standard international methods (International Society for the Advancement of Kinanthropometry protocol). Body density was predicted using Durnin and Womersley's (1974) equation, and percentage body fat was calculated from Siri's (1961) equation. Significant (P<0.05) ethnic differences in stature, body mass and BMI were observed between Japanese and Australian men, but no ethnic differences were observed in their percentage body fat and height-corrected sum of skinfold thicknesses. No differences were found in the BMI-percentage body fat relationship between the Japanese subjects living in Australia and in Japan. Significant (P<0.05) ethnic differences in the BMI-percentage body fat relationship observed from a comparison between pooled Japanese men (aged 18-40 years, BMI range 16.6-32.8 kg/m2) and Australians (aged 18-39 years, BMI range 16.1-31.4 kg/m2) suggest that Japanese men are likely to have a greater percentage body fat than Australian men at any given BMI value. From the analyses, the Japanese men were estimated to have an equivalent amount of body fat to the Australian men at BMI values that were about 1.5 units lower than those of the Australians (23.5 kg/m2 and 28.2 kg/m2, respectively). It was concluded that Japanese men have greater body fat deposition than Australian-Caucasians at the same BMI value. Japanese men may therefore require lower BMI cut-off points to identify obese individuals compared with Australian-Caucasian men.

Objective: To investigate secular trends in waist girth and skinfold measures among Australian children from 1985 and 1997/2002, matched for body size., Subjects: A total of 2604 children (10-12 years old) measured in the 1985 Australian Health and Fitness Survey and in two later surveys of South Australian schoolchildren (1997/2002), were matched for age, stature, weight and body mass index (BMI). Measurements. The matched children were compared by ANOVA on waist and hip girths, waist-to-hip ratio (WHR) and abdominal and triceps skinfolds, taken by trained anthropometrists., Results: Between the survey periods, there were significant increases in waist girth, WHR, and the two skinfold measures, but more so for abdominal skinfold. The differences in abdominal skinfold, waist girth and WHR were greater for girls than boys., Conclusions: In Australian children matched for body size, there have been increases in measures of fatness and central adiposity over the last 20 years. This suggests that reported secular trends in BMI may be under-estimating the looming public health crisis.

Objectives: To compare the physiological and anthropometric characteristics of specific playing positions and positional playing groups in junior rugby league players., Methods: Two hundred and forty junior rugby league players underwent measurements of standard anthropometry (body mass, height, sum of four skinfolds), muscular power (vertical jump), speed (10, 20, and 40 m sprint), agility (L run), and estimated maximal aerobic power (multi-stage fitness test) during the competitive phase of the season, after players had obtained a degree of match fitness., Results: Props were significantly (p<0.05) taller, heavier, and had greater skinfold thickness than all other positions. The halfback and centre positions were faster than props over 40 m. Halfbacks had significantly (p<0.05) greater estimated maximal aerobic power than props. When data were analysed according to positional similarities, it was found that the props positional group had lower 20 and 40 m speed, agility, and estimated maximal aerobic power than the hookers and halves and outside backs positional groups. Differences in the physiological and anthropometric characteristics of other individual playing positions and positional playing groups were uncommon., Conclusions: The results of this study demonstrate that few physiological and anthropometric differences exist among individual playing positions in junior rugby league players, although props are taller, heavier, have greater skinfold thickness, lower 20 and 40 m speed, agility, and estimated maximal aerobic power than other positional playing groups. These findings provide normative data and realistic performance standards for junior rugby league players competing in specific individual positions and positional playing groups.

Background: In the non-diabetic population, intramyocellular lipid (IMCL) accumulation is associated with obesity and poor muscle oxygen supply. IMCL levels are increased in type 1 diabetes, but their significance is less clear., Methods: We studied a group of 16 prepubertal boys (age 6.4-9.9 yr) with type 1 diabetes and a range of glycemic control [hemoglobin A1c (HbA1c) 6.4-10.2%]. Children's adiposity was assessed by anthropometry, muscle oxygen supply by near-infrared spectroscopy (NIRS), abdominal and IMCL content by magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS)., Results: IMCL content did not associate with muscle reoxygenation rate, abdominal adiposity, duration of diabetes, or recent glycemic control. Muscle reoxygenation rate correlated with percentage body fatness (r2 = 0.46, p = 0.004), visceral (r2 = 0.45, p = 0.007) and abdominal subcutaneous fat volume (r2 = 0.63, p = 0.0004), and dietary fat intake (r2 = 0.27, p = 0.03) but not with the duration of diabetes nor HbA1c. HbA1c was significantly related to dietary fat intake only (r2 = 0.28, p = 0.03)., Conclusion: While causality cannot be inferred, interventions aimed at improving muscle oxygen supply, or preventing its deterioration, might reduce the development of adiposity in children with type 1 diabetes.

Objective: To compare the relations of adiposity and body fat distribution to body mass index (BMI) in Australians of Aboriginal and European ancestry., Design: Cross-sectional volunteer samples., Setting: Australian Aboriginal communities in remote central and northern Australia, urban European Australians resident in Melbourne, Australia., Subjects: Healthy Aboriginal (130 women, 120 men) and European Australians (100 women, 47 men) with a BMI<30 kg/m(2), aged 18-35 y; all women were nonpregnant., Interventions: Anthropometric variables and resistance-using a four-terminal impedance plethysmograph-were measured., Results: Aboriginal women and men were significantly shorter and weighed less than European Australians (P<0.05). Aboriginal women had a significantly larger waist circumference and waist-to-hip ratio (WHR, P<0.0005) compared to European Australian women. The sum of four skinfold thicknesses (SFT) (S4) and trunk SFT was higher in Aboriginals as compared to European Australian women (P<0.0005); however, limb SFT tended to be lower (P=0.06). On the other hand, BMI was significantly lower in Aboriginals compared to European Australian men (P=0.011), as was hip circumference (P=0.001); however, WHR was significantly (P=0.007) higher. On regression analysis, Aboriginal women and men were significantly heavier than European Australians for the same height(2)/resistance (surrogate for fat-free mass) and S4 (surrogate for subcutaneous fat); and that Aboriginal men had a significantly higher BMI (by 1.2 kg/m(2); P<0.0005) for any given S4 and height(2)/resistance values, compared to European Australian men., Conclusion: Aboriginal and European Australians have a significantly different body fat distribution and fat mass for a given body weight or BMI. Use of the World Health Organization recommended BMI ranges to determine weight status may be inappropriate in Australian Aboriginal people.

Objectives: This study: (a) generated regression equations for predicting the resting metabolic rate (RMR) of 30-60-y-old Australian males from age, height, mass and fat-free mass (FFM); and (b) cross-validated RMR prediction equations which are currently used in Australia against our measured and predicted values., Design: A power analysis demonstrated that 41 subjects would enable the detection of (alpha=0.05, power=0.80) statistically and physiologically significant differences of 8% between predicted/measured RMRs in this study and those predicted from the equations of other investigators., Subjects: Forty-one males ([X]+/-s.d.:, 44.8+/-8.6 y; 83.50+/-11.32 kg; 179.1+/-5.0 cm) were recruited for this study., Interventions: The following variables were measured: skinfold thicknesses; RMR using open circuit indirect calorimetry; and FFM via a four-compartment (fat mass, total body water, bone mineral mass and residual) body composition model., Results: A multiple regression equation using mass, height and age as predictors correlated 0.745 with RMR and the s.e.e. was 509 kJ/day. Inclusion of FFM as a predictor increased both the correlation and the precision of prediction, but there was no difference between FFM via the four-compartment model (r=0.816, s.e.e.=429 kJ/day) and that predicted from skinfold thicknesses (r=0.805, s.e.e.=441 kJ/day)., Conclusions: Cross-validation analyses emphasised that equations need to be generated from a large database for the prediction of the RMR of 30-60-y-old Australian males.

This paper summarizes 41 reports on the height and mass of Australian children aged between 5.00 and 16.99 years between 1899 and 1999. In all, data on 644,613 children were collated, including individual data on 68,196 children. After primary data treatment to correct for methodological and statistical artifacts, regressions were calculated to quantify the rate of change of height and mass over time. Distributional analysis was used to probe for changes in skewness of mass values, indicative of differentially greater increases at higher percentiles. In addition, studies reporting skin fold measurements were analyzed to assess changes in subcutaneous adiposity since 1976. The results show that height has been increasing at a rate of about 1.02 cm.decade(-1), and mass at a rate of about 0.99 kg.decade(-1). The height and mass of children continue to increase, after a slowing down in the rate of increase between 1950 and 1980. Increases in mass at the higher percentiles have been much greater than at lower percentiles, particularly since the mid-1980s, suggesting that the incidence of obesity is increasing in Australian children. Furthermore, a steady linear increase in subcutaneous skin fold thicknesses since 1976 suggests that the overall level of fatness is increasing in Australian children. These findings indicate that Australian children are following trends becoming evident elsewhere in the developed world, and that we may see an increasingly large subset of increasingly obese children in the early years of the 21st century.

Objectives: The aims of this study were: (a) to generate regression equations for predicting the resting metabolic rate (RMR) of 18 to 30-y-old Australian males from age, height, mass and fat-free mass (FFM); and (b) cross-validate RMR prediction equations, which are frequently used in Australia, against our measured and predicted values., Design: A power analysis demonstrated that 38 subjects would enable us to detect (alpha = 0.05, power = 0.80) statistically and physiologically significant differences of 8% between our predicted/measured RMRs and those predicted from the equations of other investigators., Subjects: Thirty-eight males (chi +/- s.d.: 24.3+/-3.3y; 85.04+/-13.82 kg; 180.6+/-8.3 cm) were recruited from advertisements placed in a university newsletter and on community centre noticeboards., Interventions: The following measurements were conducted: skinfold thicknesses, RMR using open circuit indirect calorimetry and FFM via a four-compartment (fat mass, total body water, bone mineral mass and residual) body composition model., Results: A multiple regression equation using the easily measured predictors of mass, height and age correlated 0.841 with RMR and the SEE was 521 kJ/day. Inclusion of FFM as a predictor increased both the R and the precision of prediction, but there was virtually no difference between FFM via the four-compartment model (R = 0.893, SEE = 433 kJ/day) and that predicted from skinfold thicknesses (R = 0.886, SEE = 440 kJ/day). The regression equations of Harris & Benedict (1919) and Schofield (1985) all overestimated the mean RMR of our subjects by 518 - 600 kJ/day (P < 0.001) and these errors were relatively constant across the range of measured RMR. The equations of Hayter & Henry (1994) and Piers et al (1997) only produced physiologically significant errors at the lower end of our range of measurement., Conclusions: Equations need to be generated from a large database for the prediction of the RMR of 18 to 30-y-old Australian males and FFM estimated from the regression of the sum of skinfold thicknesses on FFM via the four compartment body composition model needs to be further explored as an expedient RMR predictor.

Objective: To determine the efficacy of applying specific body composition techniques to, and assess the relationship between body mass index (BMI) and body fat levels for Chinese Australian females., Design: Statistical comparative analysis of body composition techniques., Subjects: Australian resident females of Chinese extraction (n=40) (aged 18-45 y, mean 32.5+/-8.0; BMI range 15.7-30.9 kg/m2, mean 21.7+/-3.1 kg/m2, median 20.8 kg/m2)., Measurements: Body composition determined using bio-electrical impedance analysis (BIA), the skin-fold equations of Durnin and Womersley (D&W) and a deuterium dilution technique. Body size was calculated as the body mass index (BMI) weight/height(2) (kg/m2)., Results: With a median BMI of 20.8, range 15.7-30.9, an acceptable BMI existed for 87.5% of the subjects (mean (s.d.) 21.7+/-3.1 kg/m2). Percentage fat mass (%FM) from the deuterium dilution technique (mean (s.d.) 35.6+/-6.4) suggested 75% were overweight or obese. %FM from the D&W equation (mean (s.d.) 28.0+/-3.9) and BIA (mean (s.d.) 29.4+/-5.1) also indicated a tendency towards overweight or obese. The deuterium technique was significantly correlated and significantly different to the D&W eqn, r=0.71 P=0.001; and BIA, r=0.77, P=0.001. Bland and Altman analysis indicated that bias existed between the techniques (BIA mean (s.d.)-6.7+/-4.1) and D&W equation mean (s.d.)-6+/-4.5) when compared to the deuterium method., Conclusions: Despite a low mean BMI, body fat levels determined by the three methods suggested that, overall, an unsatisfactory body composition existed. The levels of overweight and obesity (%FM>30) were higher than reported in previous research despite a mean BMI lower than the Australian national average. Comparative analysis suggested that the body fat prediction techniques used may be precise but not accurate. Comparative results obtained for the BIA and D&W equation techniques suggest an overestimation of body fat levels for leaner individuals and under estimation for overfat individuals. The results support the notion that accurate determination of body composition and the determination of appropriate body size may require equations developed for specific ethnic populations.

Objective: To assess the usefulness of the body mass index (BMI) in identifying individuals classified as overweight or obese based on estimates of body fat percentage (BF%) obtained by the deuterium dilution (BF%DD) method. In addition, to assess the accuracy of bioelectrical impedance analysis (BIA) and skinfold thickness (SFT) measurements in the estimation of body composition of Australians at the individual and group level., Design: Cross-sectional study., Subjects: One hundred and seventeen healthy Australian volunteers of European descent, comprising of 51 males and 66 females, ranging in age from 19 to 77 y., Measurements: BMI was calculated from body weight and height. Fat-free mass (FFM) was estimated from measures of total body water (TBW) using deuterium dilution (FFM(DD)), SFT using the equations of Durnin and Womersley (Br J Nutr 1974; 32: 77-97) (FFM(SFT)), and BIA using the equations of Lukaski et al (J Appl Physiol 1986; 60: 1327-1332) (FFM(Lu)), Segal et al (Am J Clin Nutr 1988; 47: 7-14) (FFM(Se)) and Heitmann (Eur J Clin Nutr 1990; 44: 831-837) (FFM(He)). Estimates of fat mass (FM) were calculated as the difference between body weight and FFM, while BF% was calculated by expressing FM as a percentage of body weight., Results: BMI had poor sensitivity and positive predictive value in identifying individuals as being overweight/obese as classified by BF%DD. Furthermore, estimates of FFM (and hence FM) from BIA or SFT could not be used interchangeably with DD, without the risk of considerable error at the individual level. At the group level errors were relatively smaller, though statistically significant. While FFM(SFT) could be corrected by the addition of the bias (1.2 kg in males and 0.8 kg in females), no simple correction was possible with BIA estimates of FFM for any of the equations used. However, an accurate prediction of FFM(DD) was possible from the combination of FFM(He), biceps SFT and mid-arm circumference in both males and females. The bias of this prediction was small (<0.15 kg), statistically non-significant in both sexes, and unrelated to the mean FFM obtained by the two methods. The revision of Heitmann's estimate of FFM using anthropometric variables described in this study had the best sensitivity (79%), specificity (96%) and positive predictive value (92%) in identifying overweight/obese individuals in comparison to the other equations tested., Conclusion: BMI was a poor surrogate for body fatness in both males and females. The currently recommended equations for the prediction of body composition from SFT and BIA provided inaccurate estimates of FFM both at the individual and group level as compared to estimates from DD. However, Heitmann's equations, when combined with measures of the biceps SFT and mid-arm circumference, provided better estimates of FFM both at the individual and group level.

The purpose of the present study was to quantify the movement patterns and work intensities of field umpires while officiating in the three-umpire system of the Australian Football League (AFL). Five umpires were randomly selected and videoed throughout five AFL-matches played at the Brisbane Cricket Ground. Each video was analysed manually for time spent in each of four movement modalities: forward, backward, sideways and stationary which were further analysed into the categories of forward sprinting, forward cruising/jogging and forward walking; backward fast/moderate and backward slow; sideways movement and stationary. The following calculations were made: a) the total time spent performing each movement modality; b) the relative contribution (%) of time spent in each activity; and c) the work to rest ratio. The relative time contribution of each movement modality was: Sprinting (1.9+/-0.2%), Cruising/Jogging (26.1+/-3.2%), Walking (21.9+/-3.1%). Fast/Moderate Backward (14.6+/-1.2%), Slow Backward (13.6+/-1.0%), Sideways (2.2+/-0.3%) and Stationary (19.7+/-2.7%). The average time of effort for each movement modality were found to be: Sprinting (2.2+/-0.4 secs), Cruising/Jogging (6.09+/-1.3 secs), Walking (9.9+/-1.1 secs), Backward Fast/Moderate (4.4+/-0.3 secs), Backward Slow (5.2+/-0.8 secs), Sideways (1.7+/-0.1 secs) and Stationary (7.4+/-1.4 secs). The average work to rest ratio was approximately between 1:4-1:5. The current findings provide a detailed description of the movement patterns and work intensities of AFL field umpires which may be used in the development of training programs specific to the three-umpire system.

Objective: To investigate prospectively changes in weight, skin-fold measurements, waist circumference and waist/hip ratio in relation to changes in menopausal status, hormone therapy use and life-style factors., Method: The study was a 5-year follow-up of volunteers from a population-based cohort of Australian-born women aged 46-57 years at baseline: 106 premenopausal, 106 perimenopausal and 21 hormone therapy users., Results: Mean (SD) weight gain of the entire cohort over 5 years was 2.1 (5.1) kg. Baseline age was negatively associated with weight change (regression coefficient = -0.4, SE 0.1, p < 0.05). After 5 years, 20 women remained premenopausal, 80 were perimenopausal, 112 had become naturally postmenopausal and 21 remained on hormone therapy. Changes in weight were greater than zero (p < 0.05) in all groups except for the women who remained on hormone therapy. There was no significant difference in weight gain between women who remained premenopausal and those who had a natural menopause. Increases in suprailiac skin-fold measurements (p < 0.05) and in waist circumference and waist/hip ratio occurred in women who experienced the menopausal transition but not in those who took hormone therapy continuously. There was no association between weight change and baseline weight, exercise, alcohol intake or smoking., Conclusion: Weight gain was not related to change in menopausal status nor to any life-style factors measured. Women who were older at baseline gained less weight than the younger members. Suprailiac skin-fold measurements, waist circumference and waist/hip ratio all increased during the menopausal transition. Continuous hormone therapy users showed no gain in mean weight, suprailiac skin-fold measurements or waist measurements over the follow-up period.

Objective: To compare percentage total body fat (%BF) estimated by the four skinfold thickness measurement (SKF) and single-frequency bioelectrical impedance analysis (BIA) methods using three different sets of equations, to that assessed by the dual energy X-ray absorptiometric (DEXA) method using a Lunar DPX densitometer., Design: Cross-sectional study., Subjects: An Anglo-Celtic Australian population of 66 males and 130 females (age: 26-86 y)., Measurements: %BF by anthropometry, BIA using three different sets of equations and DEXA., Results: Mean %BF assessed by DEXA (%BF(DEXA)) was similar to that estimated by SKF (%BF(SKF)) in males, while %BF(DEXA) was slightly higher in females. %BF estimated by BIA (%BF(BIA)) was significantly lower than %BF(DEXA) in females, regardless of equations used for calculation, while the level of agreement between BIA and DEXA in estimating %BF in males was dependent on prediction equations used for calculation of %BF(BIA). A better agreement was obtained from the use on the prediction equations of Segal et al (1988), compared to other two sets of equations. The agreement between SKF or BIA and DEXA declined with increasing %BF., Conclusions: There was a good agreement between DEXA and SKF, and slightly less so between DEXA and BIA, in estimating %BF in an Anglo-Celtic adult population. The agreement in most cases, however, was dependent on the degree of body fatness. In comparison to DEXA, both SKF and BIA, with the use of the equations of Segal et al (1988), are applicable to estimate %BF in an Anglo-Celtic Australian population.

Objective: To investigate the association of fatness in children with dyslipoproteinemia and high blood pressure, with the purpose of proposing standards for childhood obesity which are directly related to intermediate biological parameters that predict future disease., Design: A cross-sectional study of a large, nationally representative sample of Australian schoolchildren., Subjects: 1834 children aged 9 or 15 years, with skinfolds blood lipid measurements on 1144 and with skinfolds and blood pressure measurements on 1757., Measurements: Skinfolds thicknesses measured at four locations (triceps, biceps, subscapular and suprailiac) using holtain calipers, percent body fat calculated from the sum of four skinfolds, Quetelet's index calculated from weight and height, waist and hip circumferences, plasma total cholesterol and triglycerides determined using a Technicon Autoanalyser II, high density lipoprotein cholesterol (HDLC) analysed following precipitation with heparin manganese, and systolic blood pressure (SBP) measured using a standard mercury sphygmomanometer., Results: For 9 years old girls, 15 year old girls and 9 years old boys, dichotomising their HDLC and SBP measurements by percent body fat defined the two groups most homogeneous in terms of a measure of within-group variation. The cut-points in percent body fat were in the ranges 29-35% (girls) and 17-20% (boys)., Conclusion: It is feasible to use the current biomedical status of individual children to define criteria for obesity. A cut-off point of 30% body mass as fat for girls and 20% for boys appears to be an appropriate standard.

Objectives: Several forms of weight for height or body mass index (BMI) are in widespread epidemiological and clinical use as measures of relative adiposity. The form derived by Benn for adults has been advocated for use in children and practical aspects of this proposition are considered., Methods: Height and weight data from 8492 Australian schoolchildren aged 7 to 15 were studied. A subsample of 2753 children aged 9, 12 and 15 years had skinfold thicknesses measured. The sum of four skinfolds and percentage body fat predicted from skinfolds were used as measures of adiposity., Results: Of the various forms of power type BMI examined, weight/(height)2 was most closely associated with adiposity in this sample. Benn's assumption of low correlation between height and adiposity (which holds in adults) was not satisfied in children., Conclusions: Benn's index is not recommended for general use as a body mass index in children. However, Benn's relative weight has advantages as an indirect measure of adiposity which may be of value in epidemiological studies among children.

Low body mass index (BMI, kg/m2) has been proposed as a practical measure of energy undernutrition although it has some well-known limitations. Some reports have suggested that those Australian Aborigines living a largely traditional way of life have low BMI without compromised health status and may have paradoxically high levels of subcutaneous adipose tissue. The evidence for low BMI in Australian Aborigines is reviewed from the mean data of 1,174 individuals in 26 groups of adults and from the individual data of 349 of these individuals, collected before 1970. Three of the nine groups of women had mean BMI less than 18.5 kg/m2 and 4% of the individual men and 14% of the individual women had values less than 16 kg/m2, a value regarded as indicating severe chronic energy deficiency. Skinfold thicknesses were greater than expected from the BMI, suggesting paradoxically high subcutaneous fatness. The contribution of long-leggedness to low BMI was estimated from the regression of BMI on the sitting height to stature ratio (SH/S). For the 26 groups, this was estimated to be 2 kg/m2, r2 = 31%. The relationship was weaker with the individual data, r2 = 15%. Body shape as evinced by low SH/S does contribute to low BMI in these Australian Aborigines. Single cut-offs of BMI are not applicable to all population groups and allowance may have to be made for body form when using BMI to assess nutritional status.