Search

Objective: To estimate the associations between height, weight, and three estimates of skeletal age (SA) and the strength and motor performance of male soccer players in two chronological age (CA) groups, 9-12 (n = 60) and 13-16 (n = 52) years., Methods: Height, weight, strength (grip), speed (5 m, 20 m sprints), acceleration (time at crossing 10 m in 20 m sprint), agility (figure-of-eight run), power (vertical jump), and endurance (intermittent shuttle run) were measured. SA was assessed with the TW2 RUS, TW3 RUS, and Fels methods; each SA was expressed as the standardized residual of the regression of SA on CA (SAsr). Hierarchical multiple regression was used., Results: Body size accounted for ≥50% of the variance in grip strength in both CA groups; the body size × SAsr for each method and SAsr alone added little to the explained variance. Body size, body size × SAsr interactions, and SAsr per se with each method accounted for small percentages of variance in motor tasks among players 9-12 years, while body size explained a larger proportion of variance in motor tasks (except the endurance run) among players 13-16 years; body size × SAsr interactions for TW2 and TW3 more so than Fels added to the explained variances. For the endurance run, only SAsr per se with each method accounted for significant portions of the variance., Conclusion: Body size and the three estimates of SA significantly influenced strength and motor performance, but the explained variance varied between CA groups and among SA methods and performance tasks., (© 2024 Wiley Periodicals LLC.)

Background: The aim of the study was to examine the contribution of chronological age (CA), skeletal maturation, training experience and concurrent body size descriptors, to inter-individual variance in left ventricular mass (LVM) among female adolescent soccer players., Methods: The sample included 228 female soccer players 11.8-17.1 years. Training experience defined as years of participation in competitive soccer (range 2-9 years), was obtained by interview. Stature, body mass and skinfolds (triceps, medial calf) were measured. Fat mass was estimated; Fat-free mass was derived. LVM was assessed by echocardiography. Skeletal maturity status was as the difference of skeletal age (SA, Fels method) minus CA., Results: Fat-free mass was the most prominent single predictor of LVM (R 2  = 36.6%). It was associated with an allometric coefficient close to linearity (k = 0.924, 95%CI: 0.737 to 1.112). A significant multiplicative allometric model including body mass, fat-free mass, CA, training experience and skeletal maturity status was also obtained (R = 0.684; R 2  = 46.2%)., Conclusion: Stature has limitations as a valid size descriptor of LVM. Body mass, fat-free mass, training experience, CA, body mass and skeletal maturity status were relevant factors contributing to inter-individual variability in LVM.

Interrelationships among skeletal maturity status, body size, ventilator thresholds (VT) and peak oxygen uptake (VO2peak) were considered in 47 adolescent male soccer players aged 12.5-15.4 years. Body mass, stature, and the triceps and subscapular skinfolds were measured. The latter were used to estimate fat mass and fat-free mass. Skeletal age was assessed with the Fels method. VO2peak and VO2 at the first (VT1) and second (VT2) ventilatory thresholds were determined during an incremental maximal exercise test on a motorized treadmill. Ratio standards and allometric models were used in the analysis. Scaling exponents suggested linearity for all combinations between size descriptors and physiological variables, except between log-transformed values of VT1 and body mass (mL·kg-0.801·min, 95%CI: 0.649 to 0.952). Early maturing players attained greater values than players classified as "on-time" in skeletal maturity for the three ventilatory parameters expressed in absolute terms (d ranged from 0.65 to 0.71). The differences were attenuated after normalizing for mass descriptors using ratio standards and scaled variables (d ranged from 0.00 to 0.31). The results suggested significant variability between maturity groups when moving from VT1 to maximal metabolic conditions expressed by unit of stature (VT1: t = -2.413, p = 0.02, d = 0.60; VT2: t = -2.488, p = 0.02, d = 0.65; VO2peak: t = -2.475, p = 0.02, d = 0.65). Skeletal maturity status and associated variation in overall body size affects VT1, VT2 and VO2peak. The observed scaling of ventilatory outputs for body size may be related to the better running economy and smaller body size of average maturing athletes., Competing Interests: The authors have declared that no competing interests exist.

Background: Studies of the body size and proportions of athletes have a long history. Comparisons of athletes within specific sports across time, though not extensive, indicate both positive and negative trends., Objective: To evaluate secular variation in heights and weights of male youth soccer players reported in studies between 1978 and 2015., Methods: Reported mean ages, heights, and weights of male soccer players 9-18 years of age were extracted from the literature and grouped into two intervals: 1978-99 and 2000-15. A third-order polynomial was fitted to the mean heights and weights across the age range for each interval, while the Preece-Baines model 1 was fitted to the grand means of mean heights and mean weights within each chronological year to estimate ages at peak height velocity and peak weight velocity for each time interval., Results: Third-order polynomials applied to all data points and estimates based on the Preece-Baines model applied to grand means for each age group provided similar fits. Both indicated secular changes in body size between the two intervals. Secular increases in height and weight between 1978-99 and 2000-15 were especially apparent between 13 and 16 years of age, but estimated ages at peak height velocity (13.01 and 12.91 years) and peak weight velocity (13.86 and 13.77 years) did not differ between the time intervals., Conclusion: Although the body size of youth soccer players increased between 1978-99 and 2000-15, estimated ages at peak height velocity and peak weight velocity did not change. The increase in height and weight likely reflected improved health and nutritional conditions, in addition to the selectivity of soccer reflected in systematic selection and retention of players advanced in maturity status, and exclusion of late maturing players beginning at about 12-13 years of age. Enhanced training programs aimed at the development of strength and power are probably an additional factor contributing to secular increases in body weight.

The study aimed to evaluate the mediating effect of biological maturation on anthropometrical measurements, performance indicators and subsequent selection in a group of academy rugby union players. Fifty-one male players 14-17 years of age were assessed for height, weight and BMI, and percentage of predicted mature status attained at the time of observation was used as an indicator of maturity status. Following this, initial sprint velocity (ISV), Wattbike peak power output (PPO) and initial sprint momentum (ISM) were assessed. A bias towards on-time (n = 44) and early (n = 7) maturers was evident in the total sample and magnified with age cohort. Relative to UK reference values, weight and height were above the 90th and 75th centiles, respectively. Significant (p ≤ .01) correlations were observed between maturity status and BMI (r = .48), weight (r = .63) and height (r = .48). Regression analysis (controlling for age) revealed that maturity status and height explained 68% of ISM variance; however, including BMI in the model attenuated the influence of maturity status below statistical significance (p = .72). Height and BMI explained 51% of PPO variance, while no initial significant predictors were identified for ISV. The sample consisted of players who were on-time and early in maturation with no late maturers represented. This was attributable, in part, to the mediating effect of maturation on body size, which, in turn, predicted performance variables.

Purpose: The objective of this study is to estimate the relative contribution of biological maturation to variance in the motor coordination (MC) among youth and to explore gender differences in the associations., Methods: Skeletal maturation (Tanner-Whitehouse 3), stature, body mass, and MC (Körperkoordinationstest für Kinder) were assessed in 613 youths, 284 boys and 329 girls 11-14 yr of age. Standardized residuals of skeletal age on chronological age were used as the estimate of skeletal maturity status independent of chronological age. Hierarchical multiple regression analyses were used to analyse associations between skeletal maturity status and MC., Results: Skeletal maturity status by itself, i.e., standardized residuals of skeletal age on chronological age (step 3) explained a maximum of 8.1% of the variance in MC in boys (ΔR3 in the range of 0.0%-8.1%) and 2.8% of the variance in girls (ΔR3 in the range of 0.0%-2.8%), after controlling for stature, body mass and interactions of the standardized residuals of skeletal age on chronological age with stature and body mass. Corresponding percentages for the interactions of the standardized residuals of skeletal age and stature and body mass, after adjusting for stature and body mass (step 2) were 8.7% in boys (ΔR2 in the range of 0.3%-8.7%) and 7.1% in girls (ΔR2 in the range of 0.1%-7.1%). Chow tests suggested structural changes in β-coefficients in the four MC tests among boys and girls, 12-13 yr., Conclusion: The percentage of variance in the four MC tests explained by skeletal maturation was relatively small, but the relationships differed between boys and girls. By inference, other factors, e.g., neuromuscular maturation, specific instruction and practice, sport participation, and others may influence MC at these ages.

Year-to-year changes in sprinting in youth tennis players were examined in a mixed-longitudinal study (256 male players, aged 10-15 years: 993 measurements). Height (h), body mass (BM), lower limb explosive strength (LLES), and a 5-m sprint were measured over five years. During that period, players were classified as elite or sub-elite. To account for the repeated measurements within the individual nature of longitudinal data, multilevel random effects regression analyses were used. Sprint performance improved with age at each additional 1 year of age, thus predicting ∼.016 sec improvement in five-meter sprint time by all variables of the model. It was possible to predict the performance of elite tennis players in the 5-m sprint (sec) for elite players (1.1493 - (0.0159 ċ centered age) - (0.009 ċ BM) - (0.044 ċ LLES) and sub-elite players (1.1493 - (0.0159 ċ centered age) + 0.0135 - (0.009 ċ BM) - (0.044 ċ LLES) - (0.0557 ċ centered age). Sprint performance differences between elite and sub-elite players was related to longitudinal changes in body size and lower limb strength up until age 13., (© The Author(s) 2016.)

Objectives: To examine the contribution of body size, biological maturation, and nonelite sports participation to longitudinal changes of left ventricular mass (LVM) in healthy boys., Methods: One hundred and ten boys (11.0-14.5 years at baseline) were assessed biannually for 2 years. Stature, body mass, and four skinfolds were measured. Lean body mass (LBM) was estimated. Biological maturation was assessed as years from age at peak height velocity (APHV). Sports participation was assessed by questionnaire. LVM was obtained from M-mode echocardiograms using two-dimensional images. To account for the repeated measures within individual nature of longitudinal data, multilevel random effects regression analyses were used in the analysis., Results: LVM increased on average 42 ± 18 g from 11 to 15 years (P < 0.05) and 76 ± 14 g from 3.5 years pre-APHV to 1.5 years post-APHV (P < 0.05). The multilevel model with the best statistical fit (Model B) showed that changes of 1 cm in stature, 1 year post-APHV, and 1 kg of LBM predicts 4.7, 0.5, and 1 g of LVM (P < 0.05), respectively., Conclusions: Among healthy, male adolescents aged 11-15 years individual differences in growth and biological maturation influence growth of LVM. Subcutaneous adiposity and sports participation were not associated with greater LVM., (© 2015 Wiley Periodicals, Inc.)

Background: Peak oxygen uptake (VO2peak) is routinely scaled as mL O2 per kilogram body mass despite theoretical and statistical limitations of using ratios., Aim: To examine the contribution of maturity status and body size descriptors to age-associated inter-individual variability in VO2peak and to present static allometric models to normalize VO2peak in male youth soccer players., Subjects and Methods: Total body and estimates of total and regional lean mass were measured with dual energy X-ray absorptiometry in a cross-sectional sample of Portuguese male soccer players. The sample was divided into three age groups for analysis: 8-12 years, 13-15 years and 16-18 years. VO2peak was estimated using an incremental maximal exercise test on a motorized treadmill. Static allometric models were used to normalize VO2peak., Results: The independent variables with the best statistical fit explained 72% in the younger group (lean body mass: k = 1.07), 52% in mid-adolescent players (lean body mass: k = 0.93) and 31% in the older group (body mass: k = 0.51) of variance in VO2peak. The inclusion of the exponential term pubertal status marginally increased the explained variance in VO2peak (adjusted R(2 )= 36-75%) and provided statistical adjustments to the size descriptors coefficients., Conclusion: The allometric coefficients and exponents evidenced the varying inter-relationship among size descriptors and maturity status with aerobic fitness from early to late-adolescence. Lean body mass, lean lower limbs mass and body mass combined with pubertal status explain most of the inter-individual variability in VO2peak among youth soccer players.

Relationships between skeletal maturation and fundamental motor skills and gross motor coordination were evaluated in 429 children (213 boys and 216 girls) 7-10 years. Skeletal age was assessed (Tanner-Whitehouse 2 method), and stature, body mass, motor coordination (Körperkoordinations Test für Kinder, KTK) and fundamental motor skills (Test of Gross Motor Development, TGMD-2) were measured. Relationships among chronological age, skeletal age (expressed as the standardised residual of skeletal age on chronological age) and body size and fundamental motor skills and motor coordination were analysed with hierarchical multiple regression. Standardised residual of skeletal age on chronological age interacting with stature and body mass explained a maximum of 7.0% of the variance in fundamental motor skills and motor coordination over that attributed to body size per se. Standardised residual of skeletal age on chronological age alone accounted for a maximum of 9.0% of variance in fundamental motor skills, and motor coordination over that attributed to body size per se and interactions between standardised residual of skeletal age on chronological age and body size. In conclusion, skeletal age alone or interacting with body size has a negligible influence on fundamental motor skills and motor coordination in children 7-10 years.

Background: Normalizing left ventricular mass (LVM) for inter-individual variation in body size is a central issue in human biology. During the adolescent growth spurt, variability in body size descriptors needs to be interpreted in combination with biological maturation., Aim: To examine the contribution of biological maturation, stature, sitting height, body mass, fat-free mass (FFM) and fat mass (FM) to inter-individual variability in LVM in boys, using proportional allometric modelling., Subjects and Methods: The cross-sectional sample included 110 boys of 11-15 years (12.9-1.0 years). Stature, sitting height, body mass, cardiac chamber dimensions and LVM were measured. Age at peak height velocity (APHV) was predicted and used as an indicator of biological maturation. Percentage fat was estimated from triceps and subscapular skinfolds; FM and FFM were derived., Results: Exponents for body size descriptors were k = 2.33 for stature, k = 2.18 for sitting height, k = 0.68 for body mass, k = 0.17 for FM and k = 0.80 for FFM (adjusted R(2 )= 19-62%). The combination of body descriptors and APHV increased the explained variance in LVM (adjusted R(2)( )= 56-69%)., Conclusion: Stature, FM and FFM are the best combination for normalizing LVM in adolescent boys; when body composition is not available, an indicator of biological maturity should be included with stature.

Objective: To examine the contribution of chronological age (CA), skeletal age (SA), stature, sitting stature, fat-free mass (FFM), and fat mass (FM) to interindividual variability in left ventricular mass (LVM) in male adolescent roller hockey players using allometric models., Design: Cross sectional., Setting: Training and competitive sport during adolescence., Participants: Seventy-three Portuguese male roller hockey players aged 14.5 to 16.5 years., Independent Variables: Stature, sitting stature, body mass, estimated FM and FFM, and SA assessed by the Fels method., Main Outcome Measures: Allometric modeling of LVM assessed in accordance with recommendations of the American Society of Echocardiography., Results: Hockey players (CA: 15.4 ± 0.6 years; SA: 16.4 ± 1.5 years) showed an eccentric remodeling of LV structure within the reference range (ie, 0.24-0.42), a dilated LV chamber, but no LVM increase. Exponents for body size descriptors were 2.69 for stature (R(2) = 27%; P < 0.001), 2.49 for sitting stature (R(2) = 37%; P < 0.001), 0.76 for FFM (R(2) = 31%; P < 0.001), and 0.22 for FM (R(2) = 26%; P < 0.001). The combination of size descriptors with CA and SA increased the explained variance in LVM slightly (26%-45%)., Conclusions: When stature and FM are used for indexing LVM in a sample of adolescent athletes, biological maturity status should also be considered.

The relationships between knee joint isokinetic strength, biological maturity status and body size were examined in 14-16-year-old basketball players, considering proportional allometric modeling. Biological maturity status was assessed with maturity offset protocol. Stature, body mass, sitting height, and estimated thigh volume were measured by anthropometry. Maximal moments of force of concentric and eccentric muscular actions for the knee extensors and flexors were assessed by isokinetic dynamometry at 60° s(-1). Regression analysis revealed a linear relation between maximal moments of force of the knee extensors in both muscular actions and knee flexors in concentric actions were moderately high (0.55 ≤ r ≤ 0.64). As for knee flexors in eccentric actions, a squared term of maturity indicator was significant indicating that the relationship with maturity offset tended to plateau approximately 2 years after PHV. Incorporating maturity indicator term with body size term (body mass or thigh volume) in the allometric models revealed that the size exponents for both body mass and thigh volume were reduced compared with simple allometric modeling. The results indicate a significant inter-individual variation in lower-limb isokinetic strength performance at 60° s(-1) in concentric and eccentric muscular actions in late adolescent basketball players. The variability in performance is related to inter-individual variation in estimated time before or after peak height velocity, as well as differences in body size. Proportional allometric models indicate that the influence of estimated time from age at peak height velocity on isokinetic strength performance is mostly mediated by corresponding changes in overall body mass.

Secular changes in body size, estimated fatness, skeletal maturation, and functional characteristics of youth soccer players on entry into an elite academy between 1992 and 2003 were compared. Annual selections grouped across time (1992-1995, 1996-1998, 1999-2003), playing position (goalkeeper, defender, midfielder, forward), and by eventual status in the sport (professional, non-professional) were compared. Data for 158 players (age 13.4 ± 0.4 years) at entry into the academy included skeletal age (Greulich-Pyle method), height, weight, relative fatness, four field tests of functional capacities (aerobic, anaerobic, power, speed), and quadriceps concentric strength of the dominant and non-dominant legs. MANCOVA with age as the covariate and chi square were used for comparisons across years. With few exceptions (but notably estimated [V·]O(2max)), results for player size, functional characteristics, and skeletal maturation did not differ among years. Distributions of players by skeletal maturity status and within each playing position also did not differ between years. Although related research has suggested that the anthropometric characteristics of professional players and demands of contemporary professional soccer competition increased over this period, the size, maturity, and functional characteristics of youth players on entry to an elite academy and of graduates who eventually played soccer as professionals generally did not change across annual selections from 1992 to 2003. The results suggest a lack of change in selection philosophies and practices of coaches involved in recruiting players for the academy, which in turn is reflected in consistency of specific evaluation criteria employed over the decade considered.

Background: Adolescence is characterized by increments in body size and physical performance. Short bursts of maximal intensity, requiring anaerobic metabolism, are important in many team sports including basketball., Aim: Variation of anaerobic power of adolescent basketball players (n = 93, 14-16 years) in relation to years before and after estimated age at peak height velocity (PHV) and variation in body size was considered., Methods: The cross-sectional study included chronological age, estimated age at PHV, training experience; stature, body mass (BM), free-fat mass (FFM) and estimated lower-limb volume (LLV) by anthropometry; and short-term power outputs derived from the Wingate Anaerobic Test (WAnT). Based on proportional allometric modeling, power outputs were partitioned for biological maturity status and size variables. Pearson correlations were used to estimate the associations between distance to PHV (maturity offset) and training experience with absolute and scaled estimates of short-term power., Results: Absolute WAnT increased linearly (PP, r = 0.72; MP, r = 0.74) through the interval of rapid growth of the adolescent spurt. Increments were related mainly to BM and muscle mass. Nevertheless, a residual significant positive influence of chronological age per se on maximal short-term power outputs remained independent of body size., Conclusion: Allometric modelling to partition size may reveal other potentially meaningful factors in the development of short-term performance in adolescent athletes.

Objective: The study analyzed the potential for natural selection and the demographic transition in an isolated Amerindian population in the process of secular change in body size., Setting: A genetically isolated, Zapotec-speaking community located in the Valley of Oaxaca, southern Mexico, has been studied regularly from the mid-1960s to 2000. Children, adolescents and young adults have experienced a recent secular increase in body size since 1978 after a major period of no change., Methods: Potential for natural selection and the demographic transition were analyzed over a 100-year period, ca 1900-2000. National census data, results from anthropological surveys and community archives and reports were used., Results: Opportunity for natural selection changed markedly over the last century. Demographic transition to Stage II occurred ca 1955 and preceded a secular increase in body size. The crossover between curves for mortality (I(m)) and fertility (I(f)) occurred at approximately the time of onset of the secular trend among children, adolescents and young adults, i.e. those born since the early 1970s., Conclusions: The 'classic' demographic transition occurred in the mid-1950s and preceded the secular increase in body size. A 'critical mass' of environmental improvement appears to be necessary to activate secular improvements in growth status, possibly turning on a gene complex that interacts with the improved environmental conditions. The lead time from the onset of demographic transition phase II to beginning of the secular trend is approximately 25 years (one generation) in this community.

Objective: To evaluate the growth, maturity status and functional capacity of youth soccer players grouped by level of skill., Subjects: The sample included 69 male players aged 13.2-15.1 years from clubs that competed in the highest division for their age group., Methods: Height and body mass of players were measured and stage of pubic hair (PH) was assessed at clinical examination. Years of experience in football were obtained at interview. Three tests of functional capacity were administered: dash, vertical jump and endurance shuttle run. Performances on six soccer-specific tests were converted to a composite score which was used to classify players into quintiles of skill. Multiple analysis of covariance, controlling for age, was used to test differences among skill groups in experience, growth status and functional capacity, whereas multiple linear regression analysis was used to estimate the relative contributions of age, years of training in soccer, stage of PH, height, body mass, the height x weight interaction and functional capacities to the composite skill score., Results: The skill groups differed significantly in the intermittent endurance run (p<0.05) but not in the other variables. Only the difference between the highest and lowest skill groups in the endurance shuttle run was significant. Most players in the highest (12 of 14) and high (11 of 14) skill groups were in stages PH 4 and PH 5. Pubertal status and height accounted for 21% of the variance in the skill score; adding aerobic resistance to the regression increased the variance in skill accounted for to 29%. In both regressions, the coefficient for height was negative., Conclusion: Adolescent soccer players aged 13-15 years classified by skill do not differ in age, experience, body size, speed and power, but differ in aerobic endurance, specifically at the extremes of skill. Stage of puberty and aerobic resistance (positive coefficients) and height (negative coefficient) are significant predictors of soccer skill (29% of the total explained variance), highlighting the inter-relationship of growth, maturity and functional characteristics of youth soccer players.

Objective: The study analyzed the relationship between skeletal age (SA) and the difference between skeletal and chronological ages (SA-CA) and body size among growth-stunted and well-nourished children., Methods and Materials: Tanner-Whitehouse 2 (TW2) 20 bone, radius-ulna-short (RUS) bone, and carpal SAs were analyzed in three cross-sectional samples of school children aged 6-13 years: Mestizo children (n = 396) from the city of Oaxaca, southern Mexico, and American Black (n = 570) and White (n = 432) from Philadelphia. The Oaxaca children were mild-to-moderately undernourished while the Philadelphia children were well nourished. The total sample included 1398 radiographs assessed with the Tanner-Whitehouse protocol by a single, experienced rater. Maturity scores were converted to TW2 20 bone, RUS and carpal SAs., Results: Correlations of SA and SA-CA differences with body dimensions (height, sitting height, leg length, weight, triceps skinfold, arm and estimated midarm muscle circumferences) were consistent and approximately equal in magnitude for the well-nourished samples but were different among Oaxaca children. SAs of Philadelphia children were significantly more highly correlated with body dimensions than were SA-CA differences compared to Oaxaca Mestizo children. Patterns of RUS and carpal SA correlations with body size (height, sitting height, and leg length) in Oaxaca children were different from the Philadelphia samples. Oaxaca children tended to have advanced RUS SA and delayed carpal SA., Conclusion: Long bone complexes mature earlier than round bone complexes in Oaxaca children compared to Philadelphia Black and White children, resulting in short stature in Oaxaca children. Results suggest a gene-environment interaction effect on the program for skeletal growth and maturation in undernourished Oaxaca children compared to well-nourished Black and White children from Philadelphia.

The aim of this study was to evaluate variations in the size and body proportions of elite female gymnasts associated with individual differences in maturity status. The subjects were 150 gymnasts, 14.0-17.9 years of age, who had participated in the 24th World Championship in Artistic Gymnastics, Rotterdam. Height, body mass, sitting height and biacromial and bicristal breadths were measured. Leg length was estimated as the height minus sitting height, and the ratio of sitting height to height was calculated. Information on menarcheal status was obtained by means of a questionnaire, and hand-wrist radiographs were taken to assess skeletal maturity status. For the purpose of data analysis the gymnasts were divided into three maturity groups within each single-year chronological age (CA) group from 14 to 17 years: pre-menarcheal (n=65); post-menarcheal but not skeletally mature (SA<16.0 years, n=37); post-menarcheal, skeletally mature (n=48). Differences among the groups were tested with analysis of variance and post hoc Tukey tests. The results showed that pre-menarcheal gymnasts are smaller in all dimensions compared to post-menarcheal gymnasts in all age groups but that the significance of differences varies. Post-menarcheal, skeletally mature gymnasts are heavier than pre-menarcheal gymnasts, but weight does not differ between gymnasts in the two post-menarcheal groups (with one exception, 16 years). Post-menarcheal, skeletally mature gymnasts have proportionally shorter legs than gymnasts in the other two maturity categories. Elite gymnasts of contrasting maturity status show similar trends in body size and proportions similar to those of non-athlete adolescent girls of contrasting maturity status. The results highlight the need to consider maturity-associated variation in the body dimensions of gymnasts before attributing their characteristics to the demands of regular training.

Under marginal nutritional conditions, growth in utero is related to subsequent growth and adult height. The aim of this research is to compare the young adult body size of women grouped by estimated duration of pregnancy relative to World War II. Subjects were 620 university students 18-25 years, for whom archival data for date of birth, age, height and weight were available; the BMI was calculated. Based on estimated time of pregnancy and birth relative to WWII, the women were grouped as follows: (1) pregnancy and birth before the war (n=203); (2) pregnancy before the war, birth during the war (n=54); (3) pregnancy and birth during the war (n=173); (4) pregnancy during the war, birth after the war (n=16); and (5) pregnancy and birth after the war (n=174). Heights of women born before and after WWII were significantly taller than heights of women born during the war. Though not significant, the height of women who were conceived before but born during the war was intermediate between those of women born before and during the war. The height of women conceived during the war but born after the war was similar to that of women conceived and born during the war. In contrast, BMIs and the distributions of women by weight status did not differ among the five pregnancy groups. The results suggested that heights of young adult women exposed in utero to the conditions of WWII (marginal nutritional status, maternal stress, among other factors) were shorter than women who were not exposed in utero to wartime conditions.

The contributions of height, weight and skeletal age (SA) to strength and motor performances of male soccer players 9–12 (n = 60) and 13–16 (n = 52) years were estimated. SA was assessed with the Fels method, and was expressed as the standardized residual of the regression of SA on chronological age CA (SAsr). Static strength (right + left grip), speed (5 m, 20 m sprints), acceleration (10 to 20 m), agility (figure-of-eight run), explosive strength (vertical jump) and endurance (yo–yo intermittent shuttle run, 13–16 years only) were measured. Hierarchical multiple regression was used. The interaction of SAsr with body size (height and height x weight interaction) explained most of the variance in strength in both age groups, 9–12 years (51.6%) and 13–16 years (56.7%), and in speed (31.4%, 38.7%), acceleration (39.6%), and explosive strength (32.6%) among players 13–16 years. In contrast, SAsr alone explained limited amounts of variance in strength, speed, acceleration and vertical jump among players 9–12 years (1.4–4.5%) and 13–16 years (0–0.5%). Results for agility varied with CA group, while SAsr per se was the primary contributor to endurance among players 13–16 years (18.5% of the variance). Although the influence of body size and skeletal maturity status on performances was significant, the explained variance differed among tasks and between CA groups, and suggested a role for other factors affecting performances of the soccer players. [ABSTRACT FROM AUTHOR]

Hindus and Muslims represent the two largest religions in India, and also differ in nutritional status, health-related habits and standard of living associated with economic disparities. In this context, the present study considered estimated secular changes in body size, proportions, and weight status among Hindu and Muslim Indian men. The data are from anthropological surveys in the 1970s which included measurements of height, weight and sitting height of 43,950 males 18–84 years (birth years 1891–1957). Leg length was estimated; the BMI and sitting height/height ratio were calculated. Heights of men 35 + years were adjusted for estimated height loss with age. Weight status was also classified relative to WHO criteria for the BMI. Anthropometric characteristics of the two groups were compared with MANCOVA with age and geographic region as covariates. Linear regression of height on year of birth was also used to estimate secular change in each group. Heights, weights, and BMIs tended to be, on average, greater among Muslim than Hindu men at most ages, while distributions by weight status between groups were negligible. Sitting height was greater among Muslim men but estimated leg length did not differ between groups; the sitting height/height ratio thus suggested proportionally shorter legs among Muslim men. Results of the regression analyses indicated negligible differences in secular change between groups across the total span of birth years but indicated a decline in adjusted heights of men in both groups born between 1891 through 1930s and little secular change among those born in the 1930s through 1957. The variation in heights, weights and BMIs between Muslim and Hindu men at most ages suggested variation in socio-economic status and dietary habits between the groups, whereas the negligible estimated secular changes in height between groups likely reflected economic, social, and nutritional conditions during the interval of British rule and the transition to independence. [ABSTRACT FROM AUTHOR]

Background: Motor performances of youth are related to growth and maturity status, among other factors. Aim: To estimate the contribution of skeletal maturity status per se to the motor performances of female athletes aged 10–15 years and the mediation effects of growth status on the relationships. Subjects and methods: Skeletal age (TW3 RUS SA), body size, proportions, estimated fat-free mass (FFM), motor performances, training history and participation motivation were assessed in 80 non-skeletally mature female participants in several sports. Hierarchical and regression-based statistical mediation analyses were used. Results: SA per se explained a maximum of 1.8% and 5.8% of the variance in motor performances of athletes aged 10–12 and 13–15 years, respectively, over and above that explained by covariates. Body size, proportions, and hours per week of training and participation motivation explained, respectively, a maximum of 40.7%, 18.8%, and 22.6% of the variance in performances. Mediation analysis indicated specific indirect effects of SA through stature and body mass, alone or in conjunction with FFM on performances. Conclusion: SA per se accounted for small and non-significant amounts of variance in several motor performances of female youth athletes; rather, SA influenced performances indirectly through effects on stature, body mass and estimated FFM. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate secular change in body size and weight status of adult Indian males born in 1891–1957 and surveyed in the 1970s. Methods: Data are from Anthropological Surveys. Only men were included in the surveys due to high female illiteracy and lack of female researchers. Indian society was also strongly conservative at the time, especially in rural areas, and the measurement of women by men was not permitted. Heights and weights of 43 950 males 18–84 years (born 1891–1957) were measured. The BMI was calculated; weight status of individuals was classified relative to WHO criteria and suggested criteria for the Asia‐Pacific region. Heights of men 35+ years were also adjusted for age‐related stature loss. Trends in measured and adjusted heights, body weight and the BMI, and in weight status were evaluated by age groups. Linear regression of measured height and adjusted height on year of birth was used to estimate secular effects. Results: Mean heights declined slightly with age to 50 years and declined sharply through 60+ years, while mean weights increased into the 40s and then declined. Mean BMIs were relatively stable from 30 to 60 years. The prevalence of thinness and normal weight was high, while that of overweight and obesity was low. Regression analyses indicated limited secular change across the total range of birth years but suggested a decline in adjusted heights among men born in 1891 through the 1930s, and little change among men born subsequently. Conclusions: Age‐related trends and results of the regression analyses by year of birth indicated negligible secular change in heights of Indian men 18–84 years born between 1891 and 1957. BMIs indicated a high prevalence of thinness and normal weight and low prevalence of overweight and obesity. [ABSTRACT FROM AUTHOR]

Growth and maturation are central concerns in the organization of training and competitions in youth sports. This study examined maturity-associated variation in body size and adiposity among adolescent girls participating in competitive age group youth soccer. The sample included 441 players 10.08-16.73 years of age. Stature and body mass were measured and body composition was predicted. The Fels method was used to estimate skeletal age. Skeletally maturity status (late, average or early maturing) was based on the difference between chronological and skeletal age for each player. Mean stature approximated the 50th percentiles of the general population in all competitive age groups, while mean weight fluctuated between 50th and 75th percentiles. Age- and maturity-specific means for estimated fat mass ranged between 18.0% and 28.2%. The number of players classified as skeletally mature increased with competitive age groups (under-13: 0%; under-15: 8%; under-17: 49%). In general, early maturing girls tended to be heavier than their age group peers and especially when compared to late maturing players. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to compare the young adult body size of Polish female university students born before, during, and after WWII. Methods Age, height, and weight of 492 students measured between 1956 and 1972 were accessed from the Department of Anthropology archives (Adam Mickiewicz University, Poznań). The sample was divided into three birth year cohorts relative to WWII: before ( n = 120), during ( n = 196), and after ( n = 176). Birth years spanned 1935 through 1952. BMI was calculated. Body size among birth cohorts was compared with age of the student and education level of the father as covariates (ANCOVA). Results The birth cohorts differed significantly in height ( P < .01), but not in weight and BMI. Women born during WWII were shorter than women born before and after the war; heights of latter cohorts did not differ. The trend for weight was similar, but differences were not significant. Birth cohorts did not differ in BMI. Conclusions Young adult heights of women born during WWII were shorter than the heights of women born before and immediately after the war, although differences were relatively small. [ABSTRACT FROM AUTHOR]

Short term secular change in body size and physical fitness of Polish youth 7-15 years of age resident in an industrial region of Lower Silesia in southwestern Poland was considered across two surveys, 2001-2002 and 2010-2011. Subjects were students in the same schools in both surveys 1892 boys and 1992 girls in the first and 1237 boys and 1236 girls in the second. In addition to height and weight, performances in six fitness tests were measured in each survey. Height, weight and BMI increased significantly across surveys. Statistically controlling for secular gains in height and weight, only static strength (hand grip) and running speed - agility (shuttle run) improved significantly between surveys in three age groups (7-9, 10-12, 13-15 years), while explosive power (standing long jump) showed negligible changes except in girls 13-15 years among whom performances declined significantly. Speed of upper limb movement (plate tapping), flexibility (sit and reach) and trunk strength (sit-ups) declined between surveys, except for trunk strength in boys 13-15 years which did not change. In conclusion, after statistically controlling for secular gains in body size, physical fitness items changed variably over the decade. [ABSTRACT FROM AUTHOR]

Year-to-year changes in sprinting in youth tennis players were examined in a mixed-longitudinal study (256 male players, aged 10-15 years: 993 measurements). Height (h), body mass (BM), lower limb explosive strength (LLES), and a 5-m sprint were measured over five years. During that period, players were classified as elite or sub-elite. To account for the repeated measurements within the individual nature of longitudinal data, multilevel random effects regression analyses were used. Sprint performance improved with age at each additional 1 year of age, thus predicting ~.016 sec improvement in five-meter sprint time by all variables of the model. It was possible to predict the performance of elite tennis players in the 5-m sprint (sec) for elite players (1.1493 - (0.0159 -- centered age) - (0.009 -- BM) - (0.044 -- LLES) and sub-elite players (1.1493 - (0.0159 -- centered age) + 0.0135 - (0.009 -- BM) -(0.044 -- LLES) - (0.0557 -- centered age). Sprint performance differences between elite and sub-elite players was related to longitudinal changes in body size and lower limb strength up until age 13. [ABSTRACT FROM AUTHOR]

Relations among body size, stress coping strategies, and mental health were examined in female high-school gymnasts (n=44) and basketball players (n=105), aged 14-18 years (M = 15.8, SD = 1.1), through hierarchical regression analyses. Athletes completed the Revised Ways of Coping Checklist prior to the season and the Mental Health Inventory at the end of the season. Body mass index (BMI) was also calculated. The use of adaptive over maladaptive coping strategies was associated with more positive mental health and less distress in both sports. In gymnasts, BMI was inversely related to psychological well-being and the interaction between height and less adaptive coping strategies significantly predicted psychological distress. [ABSTRACT FROM AUTHOR]

A model for adolescent involvement in physical activity (PA) that incorporates individual differences in biological maturation is presented. The biocultural model of maturity-associated variance in physical activity recognizes PA as a complex and multifaceted behaviour that exists in multiple contexts (e.g., transport, vocation, sport, exercise) and can be viewed from multiple perspectives (e.g., energy expenditure, movement counts, performance outcomes, fitness). The model holds that biological maturation can exert both direct and indirect effects on PA during adolescence. Direct effects imply a direct and unmediated effect of individual differences in maturation on PA. Indirect effects imply influences of individual differences in maturation on PA that are mediated by psychological constructs (e.g., self-perceptions, beliefs) and/or are moderated by exogenous factors (e.g., social interaction, culture) associated with pubertal maturation. [ABSTRACT FROM PUBLISHER]

Development of voluntary control of movement begins in infancy and progresses into childhood as the child attains postural, locomotor and prehensile control. With the refinement of walking, control of locomotor and manipulative abilities improves so that a considerable amount of independent action is possible. These basic movement patterns are the foundation upon which other movements and combinations of movements are subsequently developed and refined. And, movement is the substrate of physical activity. The development of motor competence during early childhood is the outcome of the interaction of the growing, maturing and developing child with his/her environments. Child-environment interactions should be viewed in the context of changing body dimensions and proportions (body scaling) and improving levels of motor competence (action scaling). Body size, proportions and composition change as the child grows, and levels of motor proficiency change as the child develops. These in turn influence the interactions between the child and his/her environments, specifically home, day care and nursery school. An additional factor is the emergence of the child's perception of these environments as they relate to his/her physical and motor characteristics. There is increasing interest in relationships between proficiency in basic movement skills and habitual physical activity in young children. Evidence indicates that specific motor skill instructional and physical activity interventions are associated with improvements in basic movement skills in preschool children. By inference, improving the motor proficiency of young children has the potential to enhance levels of habitual physical activity beyond the preschool years. Moreover, motor coordination is an important predictor of physical activity during middle childhood. Given current concern for the worldwide obesity epidemic, the movement proficiency of overweight and obese children is receiving more attention. Although the issue of reduced physical activity in obese children is somewhat equivocal, one can inquire whether proficiency in movement skills influences activity in obese children and adolescents. The teaching of skills, rules and strategies of a sport is often indicated as an objective of youth sport programs. Observations would suggest that this objective is generally achieved. Specific evidence for participants in youth sports is limited. Relative more emphasis is given to the talented few in contrast to the majority of youth participants. Individual differences are considerable and these are often dependent on the quality of coaching/instruction. [ABSTRACT FROM AUTHOR]

The purpose of this study was to cross-validate the Beunen–Malina method for non-invasive prediction of adult height. Three hundred and eight boys aged 13, 14, 15 and 16 years from the Madeira Growth Study were observed at annual intervals in 1996, 1997 and 1998 and re-measured 7–8 years later. Height, sitting height and the triceps and subscapular skinfolds were measured; skeletal age was assessed using the Tanner–Whitehouse 2 method. Adult height was measured and predicted using the Beunen–Malina method. Maturity groups were classified using relative skeletal age (skeletal age minus chronological age). Pearson correlations, mean differences and standard errors of estimate (SEE) were calculated. Age-specific correlations between predicted and measured adult height vary between 0.70 and 0.85, while age-specific SEE varies between 3.3 and 4.7 cm. The correlations and SEE are similar to those obtained in the development of the original Beunen–Malina method. The Beunen–Malina method is a valid method to predict adult height in adolescent boys and can be used in European populations or populations from European ancestry. Percentage of predicted adult height is a non-invasive valid method to assess biological maturity. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To evaluate the relationship between community well-being based on an index of marginalization and growth status of indigenous rural school children in Oaxaca. Methods: Heights and weights of a cross-sectional sample of 11,454 children, 6–14 years, from schools for indigenous rural children (escuelas albergue) in 158 municipios in Oaxaca were measured in 2007. Tertiles of an index of marginalization were used to classify the 158 municipios into three categories of community well-being: lowest (highest marginalization), low, and moderate (lowest marginalization). Multivariate analysis of covariance, controlling for age, relative isolation and population size, was used to compare body size of children by category of community well-being. Contributions of marginalization, isolation and population size to variation in body size were estimated with sex-specific linear regression. Results: Children from municipios lowest in well-being were shorter and lighter than children from municipios low and moderate in well-being. Marginalization and relative isolation accounted for 23% (boys) and 21% (girls) of the variance in height and for 21% of the variance in weight of girls. Marginalization was the predictor of weight in boys (23%). Conclusion: Community well-being was reflected in the growth status of rural indigenous school children. Compromised growth status was consistent with poor health and nutritional conditions that were and are characteristic of rural areas in the state of Oaxaca. [ABSTRACT FROM AUTHOR]

Aims: The study evaluated the growth status and secular change in body size of indigenous Tarahumara children in northern Mexico. Methods: Heights and weights of Tarahumara children 6–14 years were measured in 1990 ( n = 601) and 2007 ( n = 583); the BMI was calculated. International criteria defined weight status while United States reference data defined stunting. Results: Estimated secular gains in height from 1990 to 2007 were greatest in 6–7 year-old boys and declined with age to a small, non-significant secular decline in boys 12–14 years. Among girls secular gains in height were similar at 6–7 and 8–9 years, largest at 10–11 years and small and non-significant at 12–14 years. Secular gains in weight were similar among 6–7 and 8–9 year-old boys and girls, were greater in girls than in boys at 10–11 years and showed a small, non-significant secular decline in boys and girls 12–14 years. Secular change in the BMI paralleled those for weight. The prevalence of stunting declined from 1990 to 2007 in both sexes and all age groups except 12–14 year youth. Overweight was more prevalent in girls than boys in both years and increased from 4% to 7% in boys and 9% to 13% in girls. Obesity was not common among boys and girls in each age group and in both years. Stunting and overweight/obesity were not related in either 1990 or 2007. Conclusion: Positive secular changes in growth status have occurred in Tarahumara children 6–11 years in contrast to negligible changes among children 12–14 years. The results suggest recent improvements in health and nutrition sufficient to support a positive secular trend in younger children. [ABSTRACT FROM AUTHOR]

Objective: The present study was set in the context of two questions. First, does blood lead level exert a direct effect on measures of physical fitness? And second, might blood lead influence physical fitness indirectly through growth stunting? Background: Blood lead level is negatively associated with performances on a variety of fine motor tasks. Corresponding information on associations with measures of physical fitness and gross motor coordination are limited. Materials and methods: Schoolchildren 7-15 years of age (463 males, 436 females) living in the vicinity of copper smelters and refineries were tested for blood lead. In addition to body size and blood lead, physical fitness was measured: right and left grip strength, timed sit-ups, flexed arm hang, plate tapping, shuttle run, standing long jump and medicine ball throw. Simple reaction time was also measured. Results: The effect of blood lead level on physical fitness was indirect and small, and operated through anthropometric dimensions that more directly influenced the measures of fitness. Conclusions: Direct effects of blood lead level on indicators of physical fitness in school age youth are not evident. Blood lead level adversely affects physical fitness indirectly through growth stunting. [ABSTRACT FROM AUTHOR]

The article discusses the incidence and player risk for injury in youth football. This study is intended to estimate the incidence of injuries in youth football and to assess the relationship between player-related risk factors and the occurrence of injury. It involves a total of 678 youth of 9 to 14 years old, and members of 33 youth football teams in two central Michigan communities in the 2000 and 2001 seasons. Based from observations, a reportable injury (RI) was defined by the criteria used in the National Athletic Trainers' Association survey of several high school sports. It has been found that majority of RI during the two seasons was minor with 64 percent, the remainder was moderate with 18 percent, and major with 13 percent.

Complete longitudinal data of 136 boys aged 8–16 years and 124 girls aged 8–15 years were used to evaluate the association between maturational timing and the relative distribution of subcutaneous adipose tissue, specifically a trunk-oriented pattern of distribution. Age at peak height velocity (PHV) was the indicator of maturational timing and three skinfolds (triceps, subscapular, abdomen) were the indicators of subcutaneous fatness. Principal components analysis of the three skinfolds was used to identify indicators of relative subcutaneous adipose tissue distribution. Age at PHV and chronological age significantly influenced scores on the first principal components, which indicated centripetal fat patterning. The data suggest that early maturing subjects accumulate more subcutaneous adipose tissue on the lower trunk compared with later maturing peers of the same age and sex. Résumé. Des données longitudinales complètes de 136 garçons âgés de 8 à 16 ans et de 124 filles âgées de 8 à 15 ans ont été utilisées pour évaluer l’association entre chronologie de la maturation et distribution relative du tissu adipeux sous-cutané sur le tronc. L’âge à la vitesse de pic de croissance (VPS) de la stature est l’indicateur de maturation et trois plis cutanés (triceps, subscapulaire, abdominal) sont les indicateurs de la graisse sous cutanée. Une analyse en composantes principales des trois plis a été utilisée pour identifier les indicateurs de la distribution du tissu adipeux sous cutané. L’âge à la VPS et l’âge chronologique influencent significativement les scores du premier facteur de l’analyse qui indique une répartition centripète de la graisse. Les données suggèrent que les sujets à maturation précoce accumulent plus de tissu adipeux sous cutané dans la partie inférieure du tronc que ceux de même sexe qui ont une maturation tardive. Zusammenfassung. Vollständige longitudinale Daten von 136 8-16-jährigen Knaben und 124 8-15-jährigen Mädchen wurden verwendet, um die Beziehung zwischen dem Stand der Reifeentwicklung und der relativen Verteilung von subkutanem Fettgewebe, insbesondere ein rumpfbetontes Verteilungsmuster, zu untersuchen. Alter bei maximaler Wachstumsgeschwindigkeit (peak height velocity, PHV) wurde als Indikator für den Stand der Reifeentwicklung und die drei Hautfettfalten (Trizeps, subskapular, abdominal) als Indikatoren für Subkutanfett gewählt. Hauptkomponentenanalysen der drei Hautfettfalten wurden verwendet, um Indikatoren für die relative subkutane Fettgewebsverteilung zu identifizieren. Das Alter bei PHV und das chronologische Alter beeinflussten den Ausprägungsgrad der ersten Hauptkomponenten signifikant, der auf ein zentripetales Fettverteilungsmuster hindeutete. Die Daten weisen darauf hin, dass frühreife Jugendliche mehr subkutanes Fettgewebe im Bereich des unteren Rumpfes anreichern, als gleichgeschlechtliche Altersgenossen, die sich später entwickeln. Resumen. Se utilizaron los datos longitudinales completos de 136 chicos de entre 8 y 16 años de edad, y de 124 chicas de 8 a 15 años, para evaluar la asociación entre la edad de maduración y la distribución relativa del tejido adiposo subcutáneo, en concreto, el patrón de distribución troncal. La edad al pico de crecimiento puberal (PHV) fue el indicador de la edad de maduración, y tres pliegues de grasa subcutánea (tríceps, subescapular y abdominal) fueron los indicadores de la grasa subcutánea. Se utilizó el análisis en componentes principales de los tres pliegues para identificar los indicadores de la distribución relativa del tejido adiposo subcutáneo. La edad al PHV y la edad cronológica influían significativamente en las puntuaciones de los primeros componentes principales, que representaban el patrón de grasa centrípeto. Los datos sugieren que los sujetos con una maduración temprana acumulan más tejido adiposo subcutáneo en la parte inferior del tronco que los maduradores tardíos del mismo sexo y edad. [ABSTRACT FROM AUTHOR]

The aim of this study was to estimate the contribution of experience, body size and maturity status to variation in sport-specific skills of adolescent soccer players. The participants were 69 players aged 13.2?–?15.1 years from three clubs that competed in the highest division for their age group. Height and body mass were measured and stage of pubic hair development was assessed at clinical examination. Years of experience in football was obtained at interview. Six football skill tests were administered: ball control with the body, ball control with the head, dribbling with a pass, dribbling speed, shooting accuracy and passing accuracy. Multiple linear regression analysis was used to estimate the relative contributions of age, stage of sexual maturity, height, body mass and years of formal training in soccer to the six skill tests. Age, experience, body size and stage of puberty contributed significantly but in different combinations to the variance in four of the six skill tests: dribbling with a pass (21%; age, stage of maturity), ball control with the head (14%; stage of maturity, height, body height × body mass interaction), ball control with the body (13%; stage of maturity, years of training) and shooting accuracy (8%; stage of maturity, height; borderline significance, P ?=?0.06). There were no significant predictors for the tests of dribbling speed and passing accuracy. In conclusion, age, experience, body size and stage of puberty contributed relatively little to variation in performance in four of the six soccer-specific skill tests in adolescent footballers aged 13?–?15 years. [ABSTRACT FROM AUTHOR]

The objective was to estimate the contribution of experience, body size and maturity status to variation in the functional capacities of adolescent football (soccer) players. The sample included 69 players 13.2–15.1 years of age from three clubs which competed in the highest division for their age group in the first Portuguese national division. Height and weight were measured and stage of pubic hair development was assessed at clinical examination. The number of years of experience in football was obtained at interview. Three tests of functional capacity were administered: 30-m dash (running speed), vertical jump (explosive power) and a yo-yo intermittent endurance test (aerobic resistance). Multiple linear regression analysis was used to estimate the relative contributions of age, stage of sexual maturity, height, weight and years of formal training in football to the three indicators of functional capacity. Stage of puberty, body size and years of training accounted for 21% to 50% of the variance in the three tasks. Sexual maturity status was the primary contributor to the variance in the intermittent shuttle run, whereas weight and height were the primary contributors to the explained variance in the 30-m dash and vertical jump, respectively. In conclusion, biological maturity status significantly influences the functional capacity of adolescent football players 13–15 years of age. Training is a significant contributor to aerobic resistance, whereas weight and height are significant contributors to the sprint and vertical jump, respectively. [ABSTRACT FROM AUTHOR]

Discusses a study which compared body size and physique among Canadians of Aboriginal and European ancestry (EA) from the northern Ontario communities of Temagami and Bear Island. Materials and methods of the study; Descriptive anthropometric characteristics of the sample by age, sex and ethnicity; Stature, sitting height and body mass in selected samples of adult First Nation Canadians.

The article provides a study to examine the construct validity of the 9-item social physique anxieties (SPAS) and to compare the strength of somatotype and other biological predictors of SPA among participants in sports. Participants of the study include 214 female skaters, dancers, and divers. Social Physique Anxiety Scale (SPAS) was used followed by anthropometry. Results of the showed that somatotype was not SPA's strongest predictor because the strongest predictors were age, body weight, body mass index, and sum of six skinfolds. Several tables showing the results are provided in the article.

Abstract: Objectives: To investigate relations among body size, perceptions of coaching behaviors, and attitudes toward the coach and sport in adolescent female athletes in three sports. Design: Field correlational design. Method: Female athletes, 14–18 years, participating in high school basketball, gymnastics, and soccer (N=227) completed questionnaires dealing with the perceived frequency of coaching behaviors, evaluative reactions to the coach, and liking for the sport. Coaches rated the ability and performance of each athlete during the season. Results: Partial correlations between indicators of body size and athlete perceptions of coaching behaviors, controlling for age and ratings of ability and performance, varied by sport. Among gymnasts, measures of body size were associated with less positive and supportive interactions with coaches and less liking for the coach. Contrary to expectations, the stature of the basketball players was unrelated to their perceptions of coaching behaviors or their liking for the coach and sport. Body size was unrelated to athlete perceptions of coaching behaviors and evaluative responses in soccer. Conclusions: In support of [Petersen, A. C., & Taylor, B. (1980). The biological approach to adolescence: Biological change and psychological adaptation. In J. Adelson (Ed.), Handbook of adolescent psychology (pp. 117–155). New York: Wiley–Interscience.] Mediated Effects Model of Psychological Adaptation to Puberty, the results suggest that body size, even with age, ability and performance held constant, may engage sport specific stereotypes that influence coaches'' positive and negative behaviors, particularly in sports where body size is related to athletic potential. [Copyright &y& Elsevier]

Objectives. In adult populations, it recognized widely that waist circumference (WC) predicts health risk beyond that predicted by BMI alone; current recommendations for adults are that a combination of BMI and WC be used to classify obesity-related health risk. For children and adolescents, however, little is known about the combined influence of BMI and WC on health outcomes. The objectives of this study were determine whether BMI and WC predict coronary artery disease (CAD)risk factors independently for children and adolescents and to assess the clinical utility of using WC in combination with BMI to identify CAD risk. Methods. Subjects included 2597 black and white, to 18-year-old, male and female youths. Outcome measures included 7 CAD risk factors. In the first analysis step, BMI and WC were used as continuous variables predict CAD risk factors. In the second analysis step, participants were placed into normal-weight, overweight, and obese BMI categories and, within each BMI category, CAD risk factors were compared for groups with low and high WC values. Results. When BMI and WC were included in the same regression model to predict CAD risk factors, the added variance above that predicted by BMI or WC alone was minimal, which indicated that BMI and WC did not have independent effects on the risk factors. For example, for systolic blood pressure, BMI alone explained 7.3% of the variance, WC alone explained 7.7% of the variance, and the combination of BMI and WC explained 8.1% of the variance. When BMI and WC values were categorized with a threshold approach, WC provided information on CAD risk beyond that provided by BMI alone, particularly when the categories were used to predict elevated CAD risk factor levels. For instance, in the overweight BMI category, the high-WC group was ∼2 times more likely to have high triglyceride levels, high insulin levels, and the metabolic syndrome, compared with the low-WC group. Conclusion. These findings provide... [ABSTRACT FROM AUTHOR]