Growth and maturity status of young male table tennis players.

A maturity-associated gradient among adolescent athletes in many sports tends to favour early maturing participants. This study was aimed to describe inter-individual variance in growth and skeletal maturation among male youth table tennis. The sample included 99 players registered in competitive clubs for at least 2 years. Chronological age (CA) ranged 10.00-14.63 years. Stature and body mass were plotted relative to US references. Skeletal age (SA) was estimated with the Fels method. Maturity status was given as SA minus CA. Somatic maturation was derived from predicted age at peak height velocity. Mean values for stature and weight were above the reference medians from 10 to 13 years and at the median in the oldest group. In general, SA was in advance to CA (CA: 12.45 ± 1.28 years; SA: 13.44 ± 2.37 years). The majority of the players were early maturing according to SA (52%) and average maturing based on the somatic indicator (80%). The results suggested that table tennis tends to retain taller and heavier participants who are somewhat advanced in skeletal maturity. Participation in youth table tennis and opportunities to win need to consider age- and maturity-associated variations, particularly regarding bands for competitions.

Characteristics of select and non-select U15 male soccer players.

Baseline characteristics of 31 healthy male U15 soccer players who were classified as select or non-select at the end of the season were compared. Players were 14.4 ± 0.54 years (13.6-15.3 years) at baseline; characteristics included body size, proportions and composition, estimated maturity status, several functional capacities, and coach classifications of potential in the sport. Decisions regarding selection or non-selection were made about two months after baseline. Select and non-select U15 soccer players differed significantly in estimated maturity status, body size, proportions and estimated muscle mass, functional tests related to speed, power and strength, and coach evaluation of potential, specifically tactical skills on offense and skills associated with creativity and decision making. When age and biological maturity status were statistically controlled, select and non-select players differed significantly only on the vertical jump, grip strength, and coach ratings of tactical skills on offense and of creativity and decision making. Results of stepwise discriminant analysis highlighted the importance of coach evaluation of tactical skills associated with offense, and of power and strength in distinguishing select from non-select players. The results highlight the advantages of advanced biological maturity status among adolescent male soccer players and also the importance of coach perceptions of talent. The latter implies a need for further study of the basis of coach perceptions, specifically how they are influenced by and perhaps interact with player characteristics at different ages, and how the perceptions influence playing time and player behaviors and interactions.

Non-linear relationships between the BMI and physical fitness in Polish adolescents.

BACKGROUND: Comparisons of physical fitness in normal weight and overweight/obese youth generally highlight the negative consequences of an elevated BMI. In contrast, several studies of children and adolescents highlight the importance of variation in indicators of physical fitness across the full spectrum of BMIs from low through high. AIM: The purpose of the study was to evaluate relationships between specific physical fitness items and the BMI among youth. SUBJECTS AND METHODS: Height, weight and six physical fitness tests were measured in 1239 males and 903 females, aged 13-16 years; BMI (kg/m2) was calculated. Fitness tests were compared by weight status using sex-specific MANCOVAs, controlling for age. Sex-specific quadratic regressions of each fitness item on the BMI were also calculated. RESULTS: The sprint, standing long jump and shuttle run indicated better performances in normal than in thin and overweight/obese boys; the latter groups did not differ. Thin and normal weight boys performed better than overweight/obese boys in sit-ups and distance run. Among girls, sit-ups differed as follows: normal > thin > overweight/obese. Thin and normal weight girls performed better than overweight/obese girls in the jump, distance run and shuttle run. Normal weight girls were faster in the sprint than the overweight/obese. The quadratic regressions indicated significant non-linear relationships between the BMI and all fitness items among boys and in four items among girls. CONCLUSION: Performances on fitness tests varied with weight status. Relationships between performances and the BMI were curvilinear except for the distance run and flexibility in girls.

Differences in some developmental features between Toxoplasma gondii-seropositive and seronegative school children.

Knowledge about the influence of latent toxoplasmosis on development and general biological condition of children is scant and thus the aim of the present study was to investigate these aspects in some detail. We compare school children in rural area seropositive and seronegative to the apicomplexan parasite Toxoplasma gondii (Nicolle et Manceaux, 1908) in terms of their developmental age, body mass and body height, physical fitness and end-of-term grades. Additionally, we evaluated the risk factors of infection with T. gondii such as the presence of cats in the household and eating raw meat products. With IFAT and ELISA tests, the prevalence of anti-Toxoplasma antibodies was 41% (190 children examined) and the rate of infection was higher in girls (44%) than in boys (36%). No significant differences were observed in morphological features and physical fitness of examined children. In girls the level of developmental age measured with electrophoretical mobility of nuclei method was significantly higher and school performance significantly lower for those infected with Toxoplasma than for uninfected; this finding was particularly intriguing. Only boys who ate raw meat products were more likely to be seropositive. The study provides some new information on gender differences in reaction to Toxoplasma infection.

Somatic characteristic, morphological asymmetry and postural stability of youth male canoeists compared to control. A cross-sectional study.

OBJECTIVE: To determine the relationships between selected morphological characteristics and the level of body composition asymmetry with postural stability among canoeists and a control group. METHODS: The sample consisted of 43 males (21 canoeists 21.8±3.29 years and 22 university students 21.7±1.32 years). Measurements included body height and weight. Segmental body composition analysis was assessed using the bioelectrical impedance by determining: fat mass (FM, kg, %), fat-free mass (FFM, kg) and predicted muscle mass (PMM, kg). Postural stability was tested using the BIODEX Balance System. Anterior-posterior stability index (APSI), medial-lateral stability index (MLSI) and overall stability index (OSI) were calculated. RESULTS: Our findings suggest that the canoeists had statistically lower level of fatty tissue compared to controls. There was a statistically important difference between groups in lower limb FM (% and kg). In both groups morphological asymmetry was observed, but in most cases-in athletes. Asymmetries between right and left arms appeared in all parameters, while asymmetries between right and left legs were noted in all parameters except FM (kg). There were relationships between stature and body weight with postural stability in canoeists. Canoeists demonstrated better balance than controls, particularly in the APSI. For all stability indices, significant differences were observed between right and left legs across all participants. CONCLUSIONS: Athletes, with larger asymmetries or poorer balance, require more attention to improve performance and reduce the risk of overload injury. Future studies needed to develop sport-specific level of morphofunctional asymmetry which would be optimal for sport results and health as well.

Somatic Characteristics and Special Motor Fitness of Young Top-Level Polish Table Tennis Players.

In the present study, we aimed to identify the impact of chosen anthropometric measurements on the special physical fitness of elite junior table tennis players at different stages of sport training. A total of 87 table tennis players aged 13.4 ± 1.74 years (43.7% girls and 56.3% boys) from two Polish teams were analyzed. The anthropometry measurements included height, sitting height, body weight, arm span, humerus and femur breadths, five skinfold thicknesses, and five girths were assessed. Participants' somatotypes were also calculated using the Heath-Carter method as well as body mass index (BMI), which was constructed using the lambda, mu, sigma (LMS) method. Body composition via a bioelectric impedance analysis was also analyzed. The level of special fitness of athletes was determined using tests from the Table Tennis Specific Battery Test, assessing reaction and displacement speeds. Mesomorphic (4.1) and ectomorphic (3.8) profiles were registered for boys and girls, respectively. Boys achieved higher scores than girls for almost all variables, with the exception of ectomorphic somatotype (p = 0.274), skinfold triceps (p = 0.444), and calf skinfold medial (p = 0.609). The relationship between the body height, thickness of the skinfolds of the triceps and suprailiac, biceps, and waist circumference and arm span in all three motor tests was observed, simultaneously significantly higher results were obtained by competitors at the specialist stage of training. Knowledge of the somatic and motor characteristics of young athletes can help coaches in creating a specific training program for improved health and performance, taking into consideration the athletes' biological development, potential, and pre-disposition.

A Practical Approach to Monitoring Biomarkers of Inflammation and Muscle Damage in Youth Soccer Players During a 6-Month Training Cycle.

The aim of the study was to determine the effects of a 6-month training cycle on muscle damage and inflammatory markers in youth male soccer players. Twenty-one soccer players were tested four times: at the beginning (T1) and immediately after the pre-season period (T2), in the middle (T3) and at the end of the competitive period (T4). Muscle damage and inflammatory markers were determined in blood taken 36 hours after the match. Throughout the training cycle significant increases (p < 0.05) of creatine kinase (T1: 254.4 U·L-1; T4: 304.2 U·L-1) and lactate dehydrogenase (T1: 382.8 U·L-1; T4: 453.2 U·L-1) activities were observed. Significant changes (p < 0.05) in platelet count (T1: 210.5·109·L-1; T4: 234.2·109·L-1), percentage of lymphocyte (T1: 39.80%; T4: 42.97%), monocyte (T1: 6.88%; T4: 9.99%) and granulocyte (T1: 53.32%; T4: 47.05%) as well as in granulocyte-to-lymphocyte (T1: 1.41; T4: 1.17) and lymphocyte-to-monocyte (T1: 6.21; T4: 4.46) ratios were noted. The correlation analysis revealed statistically significant relationships (p < 0.05) between: myoglobin and the percentage of leukocyte subpopulations and the granulocyte to lymphocyte ratio; lactate dehydrogenase and the percentage of monocyte; lactate and leukocyte count. In conclusion, the reported muscle damage and inflammatory markers in T3 and T4 indicate the need for fatigue status monitoring in youth soccer players, especially in the competitive period. Moreover granulocyte to lymphocyte and lymphocyte to monocyte ratios proved to be sensitive to fatigue changes and therefore can provide coaches and sport scientists with a broader perspective on the biochemical monitoring of training status in soccer players.

Characteristics of Selected Somatic and Motor Abilities of Youth Soccer Players with Diabetes Type 1 Treated with Insulin Pump Therapy.

Long-term insulin treatment can slow the growth process and decrease physical fitness level in children. In diabetic children, these two developments should be constantly monitored. The aim of the present study was to examine differences in somatic and physical fitness characteristics between soccer-training boys with type 1 diabetes and healthy boys of the same age (reference values based on Polish population norms for somatic and motor parameters). The participants were 94 boys (8-17 years), diagnosed with diabetes, who participated in soccer training on a regular basis and received routine medical care. The study involved (a) anthropometric and body composition measurements, (b) general motor ability assessments, and (c) comparison of those characteristics with the healthy Polish population. The diabetic boys were found to have lower levels of almost all somatic traits and motor abilities as compared with the healthy boys (p ≤ 0.05). Handgrip strength was a variable with the smallest difference between the two groups. The observed differences indicate the necessity to design an appropriate control and assessment system based on simple medical and fitness field tests for diabetic children and adolescents. It will allow optimizing advanced training as well as minimize health risks before, during, or after exercise.

The Motor and Leisure Time Conditioning of Young Table Tennis Players' Physical Fitness.

The purpose of the study was to assess the association between physical fitness and the lifestyle determinants of elite junior table tennis players. The basic anthropometric characteristics (body height and body weight) were collected of 87 Polish table tennis players (girls, n = 38 and boys, n = 49, at different stages of sport training, targeted and specialized) aged 11-17 years. The level of special fitness tests from the Table Tennis Specific Battery Test were used, assessing reaction speed and displacement speed. All eight International Physical Fitness Test trials were also used to determine the level of general fitness of the participants. Selected questions from the Health Behaviour in School-Aged Children questionnaire were asked to measure factors associated with leisure time. The findings confirm a relationship between sedentary forms of leisure time activity and the training of young players at the targeted stage (Z = -2.93, p = 0.003 school days and Z = -2.12, p = 0.034 days off). Moreover, competitors with longer training experience more often chose active forms of spending free time. Knowledge of the global physical activity undertaken by young athletes during their leisure time provides a better understanding of their individual needs and may help young table tennis players to succeed at a world-class level in the future.

Morphological asymmetry, sex and dominant somatotype among Polish youth.

The aim of the present study was to determine the level of morphological asymmetry among the general population of Polish youth as it correlates to sex and body type. The anthropometric characteristics of a group of 618 Polish youths (354 males aged 19.5 ± 1.2 years and 264 females aged 19.2 ± 1.2 years) were evaluated to assess their somatotypes using the Heath-Carter method. Body composition was calculated using the bioelectrical impedance method, and the absolute asymmetry index was used for comparisons between the right and left sides of the body. Significant differentiation was observed between all morphological characteristics (≤ 0.0001) and two body types (≤ 0.0001) among sexes. Females and males largely exhibited endomorphic and mesomorphic somatotypes, respectively. The findings demonstrated that dominant somatotype and sex both affect the level of fat mass asymmetry in the arms and legs. Furthermore, significant variations in the levels of asymmetry between sexes were observed in fat mass in both the arms and legs, with greater variation observed in the arms. In the case of muscle mass, no great differences were observed between men, women, or body types. This study provides new data on the morphological asymmetry of given body composition according to somatotype and sex. This study has potential medical implications, given that a large degree of inter-limb imbalance could be shown to have a negative effect on health; the findings of the present study would therefore be important for arriving at an understanding of how to prevent such imbalances, or to mitigate their negative effects.

Physical Activity of Polish and Norwegian Local Communities in the Context of Self-Government Authorities' Projects.

The aim of this paper is to evaluate the relationship between the physical activity (PA) undertaken by two groups of residents living in Poland and Norway, and projects run by their respective local authorities. A secondary goal is to determine PA levels in the studied social groups. Two representative groups (one from each country) were examined using a diagnostic survey, supported by questionnaires and interviews. The Polish cohort consisted of 382 respondents who were residents of 11 municipalities in the Kalisz district of the Greater Poland voivodship. The Norwegian cohort was made up of 378 residents of 8 Indre Sogn municipalities from the Sogn og Fjordane region. Norwegians are twice as physically active as Poles and assess their municipal sport and recreation facilities to be much better. There is no statistically significant relationship between Polish and Norwegian PA levels in the two studied groups and their positive views on the impact of their local governments' projects to promote PA. Statistically significant correlations occurred between the frequency of PA undertaken, the time pattern of class unit, MET level (metabolic equivalent) and the declared use of the sport and recreation facilities of the two communities. Both groups are more willing to be active outdoors than indoors and thus municipal authorities should take particular care about the state of outdoor sports and recreation infrastructure. An innovative and original action model is presented to assist local authorities in their attempts to raise PA levels in their communities.

[Physical and motor development of preschool children in aspect of short stature]. / Rozwój fizyczny i motoryczny dzieci przedszkolnych w aspekcie niskoroslosci.

INTRODUCTION: Anthropometric research of morphological traits and motor ability are recommended in many environmental areas, inter alia among children. AIM OF STUDY: 1. To determine morphological diversification of preschools children aged 3-6 years with proper body height and with short stature. 2. Physical developmental assessment of children in relation to physical fitness. MATERIAL AND METHODS: The investigation was carried out in one of Poznan preschool, in 2007. It included 165 children, therein 93 girls and 72 boys, aged 3-6 years. To short stature group of children entered the ones with body height below 10 percentiles. In connection with it, there were 9% of short girls and 14 % of short boys. The analysis was performed for 2 group of children--with proper body height and with short stature girls and boys. CONCLUSION: 1. There was significant diversification within all morphological characteristic in girls and only in body height in boys. 2. It was found that body height has an influence on motor abilities. Children with proper body height have higher motor fitness level in relation to short stature children (both girls and boys). Short stature girls have worse motor fitness in all trials. Short stature boys are much better in one speed trial.

[Short athletes in view of anthropometric research]. / Niskoroslosc sportowców w swietle badan antropometrycznych.

UNLABELLED: The aim of this work, which is just a part research introduced in sport environment undertaking morphologic and motoric problems of development conditions, is the description of somatic structure of short growth sportsmen. MATERIAL AND METHOD: Research material consists of measurement results of 254 boys at the age of 15-17, who were at the stage of directed sport training process, Junior Team of Wielkopolska Voivodship. RESULTS: From 254 examined sportsmen about 12% were short body height people. They are characterized by similar body build proportions. Moreover, those competitors got similar values of analyzed quotient indices and placed similar position on self-note (the same as had sportsmen whose body height is localized above 10 centiles). CONCLUSIONS: Shorter body height, similar body build to the characteristic one of practicing sport discipline and very good results may suggest, that in case of the analyzed material, the subjects with motor predispositions revealed themselves in a natural way.

[Short countryside children in view of anthropometric research]. / Niskoroslosc dzieci wiejskich w swietle badan antropometrycznych.

INTRODUCTION: The present report deals with the analysis of the development, maturity and somatic body proportion of children from Polish country environment during growth. The research allow to describe which factors influence the biological development of children from the village. The aim of the study is the estimation of body build type and body proportions of short village children. MATERIAL AND METHODS: The data were collected in five village schools from Wielkopolska administrative unit and consist of 140 boys and 145 girls aged 7-9. Within the research some morphological parameters were made. The subjects somatotypes were determined using the Heath-Carter anthropometric method. The human body proportion also was detected. Short children (with stature deficiency) were recognized if they were under the 10 percentile for the Polish children population. The gathered material was calculated by the use of statistic methods. CONCLUSION: 1. It may be assumed that in all two groups of children there are some, but not very big differences in the development of the analysed morphological traits. Those characteristics are reflect in somatotypes of children. Short boys and girls differ a little bit than other two groups of children. They are more mesomorphic, in relation to their greater development of muscles. 2. The early period in school is rather stable in the somatic development so it could be notice that also healthy, short children will probably accelerate their growth rate in the puberty period. 3. There is a need for more research and analysis of anthropometric characteristics within the countryside children to assess physical development conditions.

[Physical fitness of short children from the rural area]. / Sprawnosc fizyczna dzieci niskoroslych ze srodowiska wiejskiego.

INTRODUCTION: In past decades we May observe in Poland the secular trend of somatic features as Wall as the phenomenon of maturity processes acceleration. On the other side physical fitness research results are diversified and are the results of multiple factors influence. From population of children, among which appear the effects of secular trend in somatic parameters we may mark the group of children diversified with body build from, as called "evolutionary norm" which may be described as short children. The aim of this work is determining physical fitness characteristics of short children in rural area of Wielkopolska region, in which we conducted wide population research in 2007. MATERIAL AND METHOD: For the analyze were used data of 145 females and 140 males at age 7-9, pupils of five basic schools from rural area of Wielkopolska region. For the estimation of physical fitness of children were used test which describe basic motor abilities. For the estimation of speed was used a 5m run. For the estimation of strength was used the dynamometric measurement of hand strength test. Coordination abilities were determined by a run on the figure of eight. Efficiency was determined on the basis of Montoy's step test. CONCLUSIONS: 1. The analyze of data shows a lower level of motor development in comparison to children whose body height is placed over 10th centile. 2. Especially important differences were o observed in the case of muscle strength what may be result of low body height, low body mass as well as low muscle mass level. 3. Low quantity of researched ones characterized with short body height (about 17% among girls and about 13% among boys) points towards delicate concluding, concerning great diversity in this group and strong influation on average values of individual fitness tests.