Somatic Maturity and Physical Performance in Male Youth Players from a Professional Soccer Academy

SUMMARY: The aim was to analyze the relationship between somatic maturation and physical performance in male youth soccer players belonging to a professional Mexican academy. In 121 male soccer aged 11 to 16 years from a professional academy the peak height velocity (PHV), percentage of adult height (PAS), jump capacity, sprint, intermittent speed and muscle mass were estimated. ANOVA was conducted to compare performance variables among maturity somatic categories and percentiles were calculated based on maturity offset using LMS method. Furthermore, a general linear model was employed to determine the explanatory variables for performance. Post-PHV soccer players demonstrated superior physical performance across several tests compared to Pre-PHV (p<0.001) and Circa-PHV (p<0.001) players. The smoothed percentile values of performance tests, based on somatic maturation, indicated progressive performance enhancement as individuals approached PHV (-2 to 2 years from PHV) (p<0.005). PHV was associated with jump capacity (p<0.001) and intermittent speed (p=0.007) while PAS was associated with time in sprint (p=.0004). In conclusion PHV and PAS explained better performance than chronological age, body composition characteristics, injuries, or training factors.

El objetivo fue analizar la relación entre la maduración somática y el rendimiento físico en futbolistas juveniles masculinos pertenecientes a una academia profesional mexicana. Métodos. En 121 futbolistas masculinos de 11 a 16 años de una academia profesional se estimó la velocidad máxima en altura (VPH), porcentaje de altura adulta (PAS), capacidad de salto, sprint, velocidad intermitente y masa muscular. Se realizó ANOVA para comparar variables de desempeño entre categorías somáticas de madurez y se calcularon percentiles en función de la compensación de madurez utilizando el método LMS. Además, se empleó un modelo lineal general para determinar las variables explicativas del desempeño. Los jugadores de fútbol post-PHV demostraron un rendimiento físico superior en varias pruebas en comparación con los jugadores Pre-PHV (p<0,001) y Circa-PHV (p<0,001). Los valores percentiles suavizados de las pruebas de rendimiento, basados en la maduración somática, indicaron una mejora progresiva del rendimiento a medida que los individuos se acercaban al PHV (-2 a 2 años desde el PHV) (p<0,005). PHV se asoció con la capacidad de salto (p<0,001) y velocidad intermitente (p=0,007) mientras que PAS se asoció con el tiempo en sprint (p=0,0004). En conclusión PHV y PEA explicaron un mejor rendimiento que la edad cronológica, las características de composición corporal, las lesiones o los factores de entrenamiento.

Parameters of pubertal growth spurt in children and adolescents living at high altitude in Peru

Abstract Objectives: The aim was to estimate the pubertal growth height of children and adolescents living in a high-altitude region of Peru using the Preece-Baines model 1 (1 PB). Methods: A cross-sectional study was conducted in schoolchildren from the department of Puno (Peru) between 3841 and 3874 masl. The age range was between 4 and 17 years. Standing height was evaluated. 1 PB was used to infer the mathematical and biological parameters of stature. Results: Mathematical parameters estimated by the 1 PB model reflected small residual standard error (RSE) values in both sexes (0.25 in boys and 0.27 in girls). In boys, the age at which peak velocity was reached (APHV) was estimated at 13.21 ± 0.33years. While in girls it was 9.96 ± 0.26years (p < 0.05). In general, girls reached APHV (y) 3.25 years earlier than boys. On the other hand, the growth velocity of maximum height [APHV (cm/y)] of boys was higher (6.33 ± 6.06 cm/y) relative to girls (6.06 ± 0.32 cm/y). Estimated final adult height (EFAH) in boys was reached at 166.020 ± 0.99 cm and height at maximum growth velocity (HPHV) was 153.07 ± 0.67 cm, while in girls they were significantly lower (EFAH; 153.74 ± 0.44 cm and HPHV: 139.73 ± 0.84 cm). Conclusions: This study showed that girls living in Puno at a high altitude in Peru reached APHV 3 years earlier than boys and at the same time reflected slower PHV. These results suggest that pubertal growth at high altitudes is slower in both sexes and especially in girls. Thus, modeling physical growth may be an important step in understanding the onset of puberty at different latitudes.

Analysis on the law of height growth spurt in adolescence of children and adolescents in Zhongshan City / 北京大学学报(医学版)

OBJECTIVE@#To analyze the characteristics of the age at peak height velocity and peak height velocity of primary and middle school students in Zhongshan City, Guangdong Province, and to explore the law of the sudden increase in adolescent height in this area, and to understand the law of height growth spurt in adolescence by longitudinal tracking of the height of children and adolescents in Zhong-shan City.@*METHODS@#Based on the physical examination database of primary and middle school students in Zhongshan City, Guangdong Province from 2005 to 2016, individuals who had been continuously tracked for more than 6 times were selected as research samples. SITAR model was used to fit the height data of the sample population, and the age at peak height velocity and peak height velocity were calcula-ted.@*RESULTS@#A total of 49 579 subjects were included in this study, including 26 524 boys and 26 008 urban students. The median follow-up ages of boys and girls were 7.74 and 7.72 years, respectively. The boy's height spurt peak age was (12.72±0.89) years, and later than the girls at the age of (10.98±0.95) years (t=207.639, P < 0.001), the boy's height spurt peak velocity of (10.12±1.49) cm/year, higher than the girls of (8.35±1.12) cm/year (t=150.826, P < 0.001). The gender differences of height spurt peak age and height spurt peak speed in urban and rural students were consistent with the whole sample. The height surge peak age of urban male students was earlier than that of rural male students, and the height surge peak speed of urban female students was lower than that of rural female students.@*CONCLUSION@#The peak age of the surge of girls was earlier than that of boys, but the peak rate of the surge of girls was lower than that of boys, the peak age of urban students was earlier than that of rural students, but the peak rate of urban boys was lower than that of rural boys in Guangdong Province.

Relação da maturação biológica com variabilidade da frequência cardíaca e resistência intermitente de jovens futebolistas / Relationship of biological maturation with heart rate variability and intermittent resistance of young soccer players

O objetivo do estudo foi investigar a relação entre maturação biológica, modulação parassimpática da frequência cardíaca e teste de resistência intermitente em jovens jogadores de futebol. Participaram do estudo 23 jovens futebolistas (15,3 ± 1,1 anos, 175 ± 6 cm, 64 ± 7 kg) das categorias sub15 e sub17 de uma equipe da 1ª divisão do campeonato paulista. O estado maturacional foi determinado pela idade do pico de velocidade de crescimento (PVC), usado como indicador relativo de maturidade somática calculada através das medidas de estatura, altura tronco-cefálica, comprimento das pernas, massa corporal e as dobras cutâneas. As medidas de variabilidade da frequência cardíaca (VFC) foram obtidas em repouso durante 5 minutos e, posteriormente, analisadas pela variável raiz quadrada da média dos quadrados das diferenças entre intervalos RR normais adjacentes (rMSSD). Os indivíduos realizaram o teste de resistência intermitente, Yoyo intermittent recovery test level 2 (YIRT 2), após as medidas de VFC terem sido obtidas. Os resultados do presente estudo mostram que não há relação entre modulação parassimpática da frequência cardíaca (rMSSD = 57,4 ± 26,4 ms) e o estado de maturação biológica (0,67 ± 0,81 anos) dos jovens futebolistas (r= 0,30; p=0,163), enquanto que o teste de resistência intermitente (YIRT 2= 658 ± 151 m) possui uma grande correlação com o pico de velocidade de crescimento (r= 0,71; p< 0,001). A modulação parassimpática da frequência cardíaca possui grande correlação com o teste de resistência intermitente dos jogadores (r= 0,54; p= 0,007). Conclui-se que a utilização da idade do PVC e da VFC como indicador de desempenho no YIRT2 em jovens futebolistas....(AU)

The aim of the study was to investigate the relationship between biological maturation, parasympathetic heart rate modulation and intermittent endurance test in young soccer players. Participated of the study 23 young soccer players (15.3 ± 1.1 years, 175 ± 6 cm, 64 ± 7 kg) of the sub15 and sub17 categories of the team from the 1st division championship Paulista. The maturational status was determined by the age of the peak height velocity (PHV), used as relative indicator of somatic maturity and are calculated trhough measures of height, trunk-cephalic height, leg length, body weight, and skinfolds. The Heart rate variability (HRV) measures were obtained in rest during 5 minutes and, posteriorly, analyzed by the variable root mean square of the successive difference (rMSSD). For the intermittent endurance test the subjects performed the Yoyo intermittent recovery test level 2 (YIRT 2), before the HRV measures has been taken. The results of the present study shown which there was not relationship between parasympathetic heart rate modulation (rMSSD = 57,4 ± 26,4 ms) and status biological maturation (0,67 ± 0,81 years) of the young soccer players (r= 0,30; p=0,163), then that the intermittent endurance test (YIRT 2= 658 ± 151 m) has a great correlation with PHV (r= 0,71; p< 0,001). The parasympathetic heart rate modulation has a great correlation with intermittent endurance test of the players (r= 0,54; p= 0,007). In this way, the use of the PHV age and HRV as indicator of performance in YIRT2 in young soccer players is suggested....(AU)

Pharyngeal Airway Dimensions in Skeletal Class II Young Adolescents : Cephalometric Study / 대한소아치과학회지

This study aimed to evaluate the nasopharyngeal and oropharyngeal dimensions of the patients with skeletal class II division 1 or division 2 patterns during the pre-peak, peak, and post-peak growth periods for comparison with a skeletal class I control group (79 for pre-peak, 40 for peak, 40 for post-peak). Total 159 lateral cephalograms (70 for skeletal class I, 51 for skeletal class II, division 1, and 38 for skeletal class II, division 2) were selected.The growth of anteroposterior dimension of the pharyngeal airway were statistically significant among growth periods. The dimension for the nasopharyngeal and oropharyngeal airway space was the smallest in the division 1 skeletal class II group followed by class II division 2 and skeletal class I.

Study on growth of height among students during their adolescence in Zhongshan, Guangdong / 中华流行病学杂志

Objective To discuss characteristics of height growth such as Peak Height Velocity (PHV) and Age at Peak Height Velocity (PHA) during adolescence,and to compare the results with other research findings.Methods Primary and middle school students' annual physical examination data of Zhongshan in 2005-2010 was used.The height velocity by age,PHV,PHA,height velocity by PHA were calculated.Results The average peak height velocity boys was ( 10.03 ± 1.67 ) cm/yr.and that of the girls was ( 8.39 ± 1.05 ) cm/yr.Both findings were close to the results from previous similar findings.The average age at which peak height velocity reached 12.28± 1.30 years for boys and 10.78 ± 1.04 years for girls,both lower than the previous findings.The correlation coefficients,between height level and PHA were -0.357 (P＜0.001) for boys and -0.338 (P＜0.001) for girls.Conclusion The height levels were positively related to the height velocity before PHA.The Zhongshan students' PHA was lower than the Beijing,Shanghai and Shenyang students,also lower than American and Britain students',but their PHVs were similar.

Menarcheal timing and growth curve shape during the adolescent growth spurt / 대한치과교정학회지

OBJECTIVE: This study investigated the onset, peak height velocity (PHV) and end of adolescent growth spurt as well as menarcheal timing deduced from surveying accumulative height growth over many years. METHODS: Ninety six students of Samgoe high school between 1st and 3rd grade that were in good health participated in the research. A survey questionnaire was distributed to examine the students' health status and menarche timing. RESULTS: Adolescent growth spurt typically began at the age of 9.9 and reached a PHV at the age of 11.6. The growth spurt ended at the age of 14.1 on average. The average age of menarche was 12.6 years, which was about one year after the PHV of adolescent growth spurt. In most cases, menarche came after PHV. But in 24% of the students, menarche and PHV was nearly coincident or menarche preceded PHV. The growth curves were classified into four types. A typical adolescent growth spurt showed one PHV on graph that drastically drops after the PHV. However, there were cases with two PHVs. CONCLUSIONS: The results indicate that individual growth patterns show large individual differences, however the categorization into the various growth curves may aid in predicting individual growth patterns.