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1.
Abstract

This study attempted to validate an anthropometric equation for predicting age at peak height velocity (APHV) in 193 Polish boys followed longitudinally 8–18 years (1961–1972). Actual APHV was derived with Preece–Baines Model 1. Predicted APHV was estimated at each observation using chronological age (CA), stature, mass, sitting height and estimated leg length. Mean predicted APHV increased from 8 to 18 years. Actual APHV was underestimated at younger ages and overestimated at older ages. Mean differences between predicted and actual APHV were reasonably stable between 13 and 15 years. Predicted APHV underestimated actual APHV 3 years before, was almost identical with actual age 2 years before, and then overestimated actual age through 3 years after PHV. Predicted APHV did not differ among boys of contrasting maturity status 8–11 years, but diverged among groups 12–15 years. In conclusion, predicted APHV is influenced by CA and by early and late timing of actual PHV. Predicted APHV has applicability among average maturing boys 12–16 years in contrast to late and early maturing boys. Dependence upon age and individual differences in actual APHV limits utility of predicted APHV in research with male youth athletes and in talent programmes.  相似文献   

2.
Abstract

This study attempted to validate an anthropometric equation for predicting age at peak height velocity (PHV) in 198 Polish girls followed longitudinally from 8 to 18 years. Maturity offset (years before or after PHV) was predicted from chronological age, mass, stature, sitting height and estimated leg length at each observation; predicted age at PHV was the difference between age and maturity offset. Actual age at PHV for each girl was derived with Preece–Baines Model 1. Predicted ages at PHV increased from 8 to16 years and varied relative to time before and after actual age at PHV. Predicted and actual ages at PHV did not differ at 9 years, but predicted overestimated actual age at PHV from 10 to 16 years. Girls of contrasting maturity status differed in predicted age at PHV from 8 to 14 years. In conclusion, predicted age at PHV is dependent upon age at prediction and individual differences in actual age at PHV, which limits its utility as an indicator of maturity timing in general and in sport talent programmes. It may have limited applicability as a categorical variable (pre-, post-PHV) among average maturing girls during the interval of the growth spurt, ~11.0–13.0 years.  相似文献   

3.
Abstract

The purpose of this study was to compare measures of body size in two samples of youth baseball players with normative data from the United States National Center for Health Statistics (NCHS) growth charts. One sample of youth baseball players participated in a local little league. The second sample of youth baseball players were members of eight of the twelve teams participating in the 1995 Dixie Youth World Series. Normative data for the United States (NCHS) were used as comparative data. Two trained anthropometrists measured standing height, sitting height, lower limb height, upper limb length, arm girth, calf girth, tricep skinfold, and abdomen skinfold on all participants. In both samples, pitchers, short stops, and first basemen were a more highly skilled group and exhibited larger body size (greater standing height, sitting height, lower limb height, upper limb length) than children who played at other positions. The standing height of local little league players was similar to the median of reference data at ages 7, 8, and 9 years. The standing height and weight of skilled players in both samples approximated the 75th percentile for standing height and weight at ages 10, 11, 12, and 13 years. The results suggest that baseball players exhibit larger body size than the normal population at young ages. Body size may be an important criterion used by coaches to select and assign young players to certain positions.  相似文献   

4.
The purpose of this study was to compare measures of body size in two samples of youth baseball players with normative data from the United States National Center for Health Statistics (NCHS) growth charts. One sample of youth baseball players participated in a local little league. The second sample of youth baseball players were members of eight of the twelve teams participating in the 1995 Dixie Youth World Series. Normative data for the United States (NCHS) were used as comparative data. Two trained anthropometrists measured standing height, sitting height, lower limb height, upper limb length, arm girth, calf girth, tricep skinfold, and abdomen skinfold on all participants. In both samples, pitchers, short stops, and first basemen were a more highly skilled group and exhibited larger body size (greater standing height, sitting height, lower limb height, upper limb length) than children who played at other positions. The standing height of local little league players was similar to the median of reference data at ages 7, 8, and 9 years. The standing height and weight of skilled players in both samples approximated the 75th percentile for standing height and weight at ages 10, 11, 12, and 13 years. The results suggest that baseball players exhibit larger body size than the normal population at young ages. Body size may be an important criterion used by coaches to select and assign young players to certain positions.  相似文献   

5.
许汪宇  蔡广  沈勋章  葛珺 《体育科研》2013,34(1):75-78,103
目的：探讨女青少年运动员生长发育与15S无氧功特点及其相关关系．对象和方法：以650名上海市10-18岁女运动员为对象,分别测试身高、体重、体脂率、肌肉量、瘦体重和立定跳远．并采集15S无氧功率自行车的最大功率、平均功率、最大转速、最大转速出现时间等指标,分析其特点及相关性、结果：上海市女青少年运动员身高及体重在10-13岁、最大和平均功率在㈤～15岁增长最快,15岁后趋于稳定,瘦体重、体重和肌肉与功率的相关性依次降低、结论：对女青少年运动员速度力量的训练要在15岁之前,评价女青少年运动员磷酸原代谢能力时最好使用瘦体重相对功率。  相似文献   

6.
Abstract

Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a health risk. Even in athletes an increased adiposity affects health and performance. Sedentary behaviour has been associated with higher levels of adiposity, independent of moderate-to-vigorous physical activity. However, it is unclear whether this independent relationship still exists in highly trained athletes. The aim of this study was to examine the association of sedentary behaviour with body fatness in elite athletes. Cross-sectional data from 82 male athletes (mean age 22 years) were used. Total and regional body composition was measured by dual energy X-ray absorptiometry. Self-reported time spent in sedentary behaviour and weekly training time was assessed in all participants at one time point and multiple regression analyses were used. Sedentary behaviour predicted total fat mass (β = 0.77; 95% CI: 0.36–1.19, P < 0.001) and trunk fat mass (β = 0.25; 95% CI: 0.07–0.43, P = 0.007), independent of age, weekly training time, and residual mass (calculated as weight-dependent variable) but not abdominal fat. Also, no associations of sedentary behaviour with fat-free mass, appendicular lean soft tissue, and body mass index were found. These findings indicate that athletes with higher amounts of sedentary behaviour presented higher levels of total and trunk fatness, regardless of age, weekly training time, and residual mass. Therefore, even high moderate-to-vigorous physical activity levels do not mitigate the associations between sedentary behaviour and body fatness in highly trained athletes.  相似文献   

7.
This study aimed to identify physique characteristics (anthropometry, somatotype, body proportionality) of Brazilian female artistic gymnasts, and to compare them across competitive levels (sub-elite versus non-elite) within competitive age-categories. Two hundred forty-nine female gymnasts (68 sub-elite; 181 non-elite) from 26 Brazilian gymnastics clubs, aged 9–20 years and split into four age-categories, were sampled. Gymnasts were assessed for 16 anthropometric traits (height, weight, lengths, widths, girths, and skinfolds); somatotype was determined according to Heath-Carter method, body fat was estimated by bioimpedance, and proportionality was computed based on the z-phantom strategy. Non-elite and sub-elite gymnasts had similar values in anthropometric characteristics, however non-elite had higher fat folds in all age-categories (P < 0.01). In general, mesomorphy was the salient somatotype component in all age-categories, and an increase in endomorphy, followed by a decrease in ectomorphy across age was observed. Regarding proportionality, profile similarity was found between sub-elite and non-elite within age-categories. In conclusion results suggest the presence of a typical gymnast’s physical prototype across age and competitive level, which can be useful to coaches during their selection processes in clubs and regional/national teams.  相似文献   

8.
ABSTRACT

Purpose: This study examined the relationships between the Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1) and resting heart rate variability (HRV) and submaximal 5?-5? test derived measures in novice male soccer players. Methods: Forty players (11.54 ± 0.58 years) from a soccer academy participated in this study, performing physical tests on two different days, separated by 48 h, as follows: (day 1) resting HRV and Yo-Yo IR1 test, and (day 2) anthropometric assessments (for peak height velocity assessment [PHV]) and the 5?-5? test. The Pearson product-moment correlation coefficient was used to determine the correlations between Yo-Yo IR1 performance and the remaining variables. A partial correlation analysis was further performed using age, stature, body mass, distance to PHV, and age at PHV as “confounders.” Results: The highest correlation score was observed between Yo-Yo IR1 performance and resting HRV, when the absolute age was used as confounder (r = 0.72; p < .05). Conclusions: We observed that a practical measure of parasympathetic activity at rest is largely associated with performance obtained during a traditional intermittent endurance performance test.  相似文献   

9.
Although high levels of sitting time are adversely related to health, it is unclear whether moving from sitting to standing provides a sufficient stimulus to elicit benefits upon markers of chronic low-grade inflammation in a population at high risk of type 2 diabetes (T2DM). Three hundred and seventy two participants (age = 66.8 ± 7.5years; body mass index (BMI) = 31.7 ± 5.5kg/m2; Male = 61%) were included. Sitting, standing and stepping was determined using the activPAL3TM device. Linear regression modelling employing an isotemporal substitution approach was used to quantify the association of theoretically substituting 60 minutes of sitting per day for standing or stepping on interleukin-6 (IL-6), C-reactive protein (CRP) and leptin. Reallocating 60 minutes of sitting time per day for standing was associated with a ?4% (95% CI ?7%, ?1%) reduction in IL-6 (p = 0.048). Reallocating 60 minutes of sitting time for light stepping was also associated with lower IL-6 levels (?28% (?46%, ?4%; p = 0.025)). Substituting sitting for moderate-to-vigorous (MVPA) stepping was associated with lower CRP (?41% (?75%, ?8%; p = 0.032)), leptin (?24% (?34%, ?12%; p ≤ 0.001)) and IL-6 (?16% (?28%, 10%; p = 0.036). Theoretically replacing 60 minutes of sitting per day with an equal amount of either standing or stepping yields beneficial associations upon markers of chronic-low grade inflammation.  相似文献   

10.
Growth and maturation impact the selection, development and progression of youth athletes. Individual differences in the growth and maturity may afford a performance advantage, clouding coaches and practitioners’ perceptions regarding current ability and future potential. This may result in the exclusion of talented, yet less physically gifted athletes. Participants were 91 male (n = 47) and female (n = 44) elite British Junior tennis players, 8–17 years of age (12.5 ± 1.9 years). Height and body mass were measured and compared to growth charts; hand-wrist radiographs were taken. Skeletal age (SA) was estimated with the Fels method and contrasted to chronological age (CA). Mean height and body mass of individual players ranged between the 50th and 90th centiles for age and sex. Females were advanced in SA relative to CA (0.3–0.89 years.) from 8 years. Males were average to delayed in maturation from 8 to 12 years, but advanced in SA from 14 to 16 years (0.75–1.23 years). Individual differences in growth and maturation appear to contribute towards the selection of elite junior tennis players, with a bias towards males and females who are advanced in maturation and comparatively tall and heavy for their age. This has important implications for talent identification and development.  相似文献   

11.
Abstract

The aims of this study were to (1) investigate the influence of general anthropometric variables, handball-specific anthropometric variables, and upper-limb power and strength on ball-throwing velocity in a standing position (νball), and (2) predict this velocity using multiple regression methods. Forty-two skilled male handball players (age 21.0 ± 3.0 years; height = 1.81 ± 0.07 m; body mass = 78.3 ± 11.3 kg) participated in the study. We measured general anthropometric variables (height, body mass, lean mass, body mass index) and handball-specific anthropometric parameters (hand size, arm span). Upper-limb dynamic strength was assessed using a medicine ball (2 kg) throwing test, and power using a one-repetition maximum bench-press test. All the variables studied were correlated with ball velocity. Medicine ball throwing performance was the best predictor (r = 0.80). General anthropometric variables were better predictors (r = 0.55–0.70) than handball-specific anthropometric variables (r = 0.35–0.51). The best multiple regression model accounted for 74% of the total variance and included body mass, medicine ball throwing performance, and power output in the 20-kg bench press. The equation formulated could help trainers, athletes, and professionals detect future talent and test athletes' current fitness.  相似文献   

12.
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.  相似文献   

13.
This study aimed to identify the maturity-related differences and its influence on the physical fitness, morphological and performance characteristics of young elite paddlers. In total, 89 kayakers and 82 canoeists, aged 13.69 ± 0.57 years (mean ± s), were allocated in three groups depending on their age relative to the age at peak height velocity (pre-APHV, circum-APHV and post-APHV) and discipline (kayak and canoe). Nine anthropometric variables, a battery of four physical fitness tests (overhead medicine ball throw, countermovement jump, sit-and-reach test and 20 m multistage shuttle run test) and three specific performance tests (1000, 500 and 200 m) were assessed. Both disciplines presented significant maturity-based differences in all anthropometric parameters (except for fat and muscle mass percentage), overhead medicine ball throw and all performance times (pre > circum > post; P < 0.05). Negative and significant correlations (P < 0.01) were detected between performance times, chronological age and anthropometry (body mass, height, sitting height and maturity status), overhead medicine ball throw and sit and reach for all distances. These findings confirm the importance of maturity status in sprint kayaking and canoeing since the more mature paddlers were also those who revealed largest body size, physical fitness level and best paddling performance. Additionally, the most important variables predicting performance times in kayaking and canoeing were maturity status and chronological age, respectively.  相似文献   

14.
Abstract

In this cross-sectional study, we evaluated the body composition and dietary intake of 44 adolescent tennis players. After being divided into two groups (age 10–13 years and age 14–18), the players had their weight, height, and sexual maturation assessed. Dual-energy X-ray absorptiometry was used to assess body composition. Food intake was obtained from a non-consecutive 4-day food record. The data were analysed using the Virtual Nutri v.1.0 software and compared with the present recommendations for adolescent athletes or dietary reference intakes. Body mass index and body fat for tennis practice were adequate for 89% and 71% of the tennis players respectively, regardless of age group. A calorie deficit greater than 10% of energy expenditure was observed in 32% of the sample. Fifty percent of the athletes consumed carbohydrates in accordance with recommended values. Protein and lipid intakes were above recommended values, while fibre, calcium, potassium, magnesium, and folic acid intakes were below recommendation for 98%, 80%, 100%, 100%, and 98% of the tennis players respectively. The observed nutritional deficiencies represent an additional barrier for adolescents engaged in competitive sports to achieve an optimum nutrition to maintain growth, health, and performance.  相似文献   

15.
This study investigated the role of maturity timing in selection procedures and in the specialisation of playing positions in youth male basketball. Forty-three talented Dutch players (14.66 ± 1.09 years) participated in this study. Maturity timing (age at peak height velocity), anthropometric, physiological, and technical characteristics were measured. Maturity timing and height of the basketball players were compared with a matched Dutch population. One-sample t-tests showed that basketball players were taller and experienced their peak height velocity at an earlier age compared to their peers, which indicates the relation between maturity timing and selection procedures. Multivariate analysis of variance (MANOVA) showed that guards experienced their peak height velocity at a later age compared to forwards and centres (P < .01). In addition, positional differences were found for height, sitting height, leg length, body mass, lean body mass, sprint, lower body explosive strength, and dribble (P < .05). Multivariate analysis of covariance (MANCOVA) (age and age at peak height velocity as covariate) showed only a significant difference regarding the technical characteristic dribbling (P < .05). Coaches and trainers should be aware of the inter-individual differences between boys related to their maturity timing. Since technical characteristics appeared to be least influenced by maturity timing, it is recommended to focus more on technical characteristics rather than anthropometric and physiological characteristics.  相似文献   

16.
Abstract

Bioelectrical impedance spectroscopy (BIS) provides an affordable and practical assessment of fat-free mass (FFM). However, little information is available on the assessment of changes in fat-free mass in top-level athletes using BIS. The aim of this study was to examine the accuracy of BIS in tracking changes in fat-free mass of elite male judo athletes from a period of weight stability to just before competition, using the four-compartment model (4C model) as reference method. In total, 27 elite male judo athletes (age 22.2 ± 2.8 years) were evaluated. Measures of body volume assessed by air displacement plethysmography, bone mineral content by dual-energy X-ray absorptiometry, and total-body water assessed with deuterium dilution were used in a 4C model. Fat-free mass was also assessed by BIS (FFMBIS). Changes in FFMBIS were not significantly different from measured by the reference method (P = 0.000). Furthermore, the r 2 was 0.62 and the standard error of the estimate was 1.03 kg. The limits of agreement ranged from ?3.36 to 2.59 kg with no bias observed. These findings demonstrate the viability of BIS as a valid tool for tracking fat-free mass in elite male judo athletes. However, based on the wide limits of agreement observed, BIS is less valid at an individual level for tracking fat-free mass in these athletes.  相似文献   

17.
The objective of this study was to describe the anthropometric profiles of elite older triathletes participating in the 2009 Ironman Brazil and to compare their somatotype, anthropometric and body composition characteristics with those of elite young triathletes and older non-athletes. The sample consisted of 64 males, divided into three groups: (1) older triathletes (n = 17), (2) young triathletes (n = 24), and (3) older non-athletes (n = 23). Somatotype was analysed according to the Carter and Heath ( 1990 ) method. Body mass index, sum of four skinfolds, percentage body fat, body fat mass, and fat-free mass were also estimated. Older non-athletes had higher endomorphy, sum of four skinfolds, fat percentage, and body fat mass than the athletes. Older athletes who participated in the Ironman and elite young triathletes had higher fat-free mass than older non-athletes. Older triathletes and older non-athletes were considered mainly endomorphic mesomorphs and young triathletes mainly ectomorphic mesomorphs. The findings that characterize the anthropometric profile of athletes in this sports modality could be used as a reference.  相似文献   

18.
The purpose of this study was to evaluate the dietary practices of soccer players of different ages. The diets of the members of four soccer teams (mean ages of 14.0, 15.0, 16.6 and 20.9 years, respectively) were examined. Our results show that the caloric intake per kilogram of body mass was significantly higher among the youngest players when compared with the adult players (P < 0.05). The contribution of carbohydrates to total energy intake was lower than that recommended for athletes. This contribution decreased with age from 47.4% of total energy intake for the 14-year-olds to 44.6% for the adult players. No significant differences in protein or total fat intake were detected among the teams examined. Overall, our results show that the nutritional intake of the soccer players was not optimal, and that this intake was poorer among the adult players than among the adolescents. On the basis of our results, we recommended that nutritional education should be given to soccer players at an early age and should continue throughout adolescence, not only with a view to improving performance but also to promoting more healthy dietary practices in the long term.  相似文献   

19.
In this cross-sectional study, we evaluated the body composition and dietary intake of 44 adolescent tennis players. After being divided into two groups (age 10-13 years and age 14-18), the players had their weight, height, and sexual maturation assessed. Dual-energy X-ray absorptiometry was used to assess body composition. Food intake was obtained from a non-consecutive 4-day food record. The data were analysed using the Virtual Nutri v.1.0 software and compared with the present recommendations for adolescent athletes or dietary reference intakes. Body mass index and body fat for tennis practice were adequate for 89% and 71% of the tennis players respectively, regardless of age group. A calorie deficit greater than 10% of energy expenditure was observed in 32% of the sample. Fifty percent of the athletes consumed carbohydrates in accordance with recommended values. Protein and lipid intakes were above recommended values, while fibre, calcium, potassium, magnesium, and folic acid intakes were below recommendation for 98%, 80%, 100%, 100%, and 98% of the tennis players respectively. The observed nutritional deficiencies represent an additional barrier for adolescents engaged in competitive sports to achieve an optimum nutrition to maintain growth, health, and performance.  相似文献   

20.
随机抽取第六届全国大学生武术锦标赛的运动员共51人作为研究对象,按性别分为3组,前4名为第1组,5~8名为第2组,未进入前8名的为对照组,分别测量他们的身体形态、身体成分、身体素质和赛前心理状态。结果:男运动员在身高、体重、脂肪比率,肌肉含量、去脂体重、WHR、BMI、肺活量、肺活量指数、握力、立定跳远、反应时和平衡性方面,第1组、第2组与对照组相比,均没有显著性意义(P>0.05),握力指数和坐位体前屈第1组显著性高于其他组(P<0.05);女运动员的肌肉含量、去脂体重和坐位体前屈第1组显著性高于对照组(P<0.05),第2组在身高、脂肪比率、去脂体重和握力方面显著性高于第1组和对照组(P<0.05~0.01),坐位体前屈和反应时显著性低于第1组(P<0.05~0.01)。第1组运动员在赛前认知状态焦虑和躯体状态焦虑显著性均低于第2组和对照组(P<0.05~0.01),而自信心第1组、第2组和对照组之间没有显著性差异(P>0.05)。结论:力量和柔韧性是影响男子武术运动员比赛成绩的重要因素;肌肉含量、去脂体重和坐位体前屈是影响女子武术运动员比赛成绩的重要因素;赛前认知状态焦虑和躯体状态焦虑也是影响武术比赛成绩的重要因素之一,而状态自信心对比赛成绩影响不大。  相似文献   

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