scholarly journals Kinetics and kinematics of sprinting in mid and post peak height velocity female athletes

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Kaushik Talukdar ◽  
Dr Craig Harrison ◽  
Professor Mike McGuigan ◽  
Dr Robert Borotkanics
Keyword(s):  
Contact Time ◽  
Female Athletes ◽  
Step Length ◽  
Peak Height ◽  
Height Velocity ◽  
Stride Frequency ◽  
Maximal Velocity ◽  
Leg Length ◽  
Peak Height Velocity ◽  
Young Females

Sprinting speed is a crucial physical capacity and can change throughout an athlete’s growth. Previous research has shown that both kinetic and kinematic variables change across maturation in young males. However, due to the changes in growth and hormonal levels, the kinetic and kinematic factors associated with sprinting may vary in young females compared to their male counterparts.  Therefore, determining kinetics (force, maximal power) and kinematics (step length, step frequency, contact time and flight time) associated with sprinting in young females can provide valuable insights into training for this cohort. Thirty-two young female athletes, 11 mid-peak height velocity (PHV) age (12.8±0.6) and 21 post PHV (13.5±0.93) performed two 15 and 30 m sprints each. Theoretical velocity, maximal velocity, step length, force and power max were significantly higher in post PHV girls (p<0.05). Univariate regression analysis reported that the best predictors of velocity (15 and 30 m) were contact time, power max, stride frequency, step length and leg length with contact time being the strongest predictor. The findings of this research provide insight into the natural development of sprinting in young females and will help practitioners specifically develop training programs that can effectively improve sprinting kinetics and kinematics in this cohort.

scholarly journals Maximal Sprint Speed in Boys of Increasing Maturity

2015 ◽  
Vol 27 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Robert W. Meyers ◽  
Jonathan L. Oliver ◽  
Michael G. Hughes ◽  
John B. Cronin ◽  
Rhodri S. Lloyd
Keyword(s):  
Contact Time ◽  
Stride Length ◽  
Peak Height ◽  
Flight Time ◽  
Sprint Performance ◽  
Height Velocity ◽  
Stride Frequency ◽  
Peak Height Velocity ◽  
Sprint Speed ◽  
Maximal Speed

The purpose of this study was to examine the natural development of the mechanical features of sprint performance in relation to maturation within a large cohort of boys. Three hundred and thirty-six boys (11-15 years) were analyzed for sprint performance and maturation. Maximal speed, stride length (SL), stride frequency (SF), flight time (FT) and contact time (CT) were assessed during a 30m sprint. Five maturation groups (G1-5) were established based on age from peak height velocity (PHV) where G1=>2.5years pre-PHV, G2 = 2.49-1.5years pre-PHV, G3 = 1.49-0.5years pre-PHV, G4 = 0.49years pre- to 0.5years post-PHV and G5 = 0.51-1.5years post-PHV. There was no difference in maximal speed between G1, G2 and G3 but those in G4 and G5 were significantly faster (p < .05) than G1-3. Significant increases (p < .05) in SL were observed between groups with advancing maturation, except G4 and G5 (p > .05). SF decreased while CT increased (both p < .05) between G1, G2 and G3, but no further significant changes (p > .05) were observed for either variable between G3, G4 and G5. While G1-3 increased their SL, concomitant decreases in SF and increases in CT prevented them from improving maximal speed. Maximal sprint speed appears to develop around and post-PHV as SF and CT begin to stabilize, with increases in maximal sprint speed in maturing boys being underpinned by increasing SL.

scholarly journals Development of Physical Performance Tasks during Rapid Growth in Brazilian Children: The Cariri Healthy Growth Study

2019 ◽  
Vol 16 (24) ◽  
pp. 5029
Author(s):  
Simonete Silva ◽  
Hudday Mendes ◽  
Duarte Freitas ◽  
António Prista ◽  
Go Tani ◽  
...  
Keyword(s):  
Sex Differences ◽  
Physical Performance ◽  
Longitudinal Design ◽  
Handgrip Strength ◽  
Peak Height ◽  
Height Velocity ◽  
Maximal Velocity ◽  
Peak Height Velocity ◽  
Performance Tasks ◽  
Age Cohorts

Growth and physical performance scores were studied around three years of attainment of peak height velocity (PHV). We aimed to estimate the age at peak velocity, or at peak rate, in physical performance tasks, and sex-differences when aligned by biological age. A total of 131 boys and 123 girls, 8 to 14 years of age were recruited from the Cariri region of Brazil. A mixed longitudinal design was used with four overlapping age cohorts: 8, 10, 12, and 14 years, followed for three years, with measurements performed at 6 month intervals. Height, 12 min run (12mR), handgrip strength (HG), standing long jump (SLJ), and shuttle run (SR) velocities were estimated using a non-smooth mathematical procedure. Age at PHV was 13.4 ± 1.6 years in boys compared with 12.2 ± 2.3 years in girls. Maximal velocity in SLJ was attained 6 and 3 months prior to PHV in boys and girls, respectively. For HG, peaks were attained 9 months after PHV in boys and 15 months after PHV in girls. Maximal velocity in 12mR was attained 6 months before PHV in boys and at PHV in girls, whereas a peak in SR occurred 12 months after PHV in both sexes. In conclusion, dynamic changes in physical performance relative to PHV appear similar in both sexes, although sex differences were evident in some motor tests.

scholarly journals Comparison of maturation and physical performance in basketball athletes of different playing positions

2019 ◽  
Vol 21 ◽  
Author(s):  
Lilian Keila Barazetti ◽  
Pedro Rafael Varoni ◽  
Fernando de Souza Campos ◽  
Michelli Demarchi ◽  
Lucielle Baumann ◽  
...  
Keyword(s):  
Physical Performance ◽  
Body Mass ◽  
Aerobic Power ◽  
Vertical Jump ◽  
Peak Height ◽  
Lower Limbs ◽  
Height Velocity ◽  
Leg Length ◽  
Peak Height Velocity ◽  
Sitting Height

Abstract The aim of this study was to compare the characteristics of somatic maturation, anthropometric and physical performance (vertical jump and aerobic power) in young basketball players of different playing positions (under 13 years) and analyze these relationships using Peak Height Velocity (PHV) as a measure of somatic maturation. For this, 26 male athletes were evaluated. Anthropometric variables were: body mass, standing and sitting height, and length of lower limbs. Maturation was determined by age at PHV. Physical performance was determined by lower limb power (counter movement jump - CMJ) and aerobic power (Intermittent Recovery Test) tests. MANOVA reported significant differences (p<0.05) among playing positions regarding variables Maturity Offset, estimated PHV age, standing height, sitting height, estimated leg length, body mass and Yo-Yo IR1. In addition, it was identified that point guards reached estimated PHV at later age than their peers who act as small forwards and centers. Regarding CMJ, no significant differences were identified among playing positions, but in relation to aerobic power, point guards and small forwards presented higher performance. These findings confirm that maturation has great effect on growth and physical performance measures and the estimated PHV age is an applicable tool in young athletes, mainly aiding professionals in structuring the teaching-learning- training process in this age group.

scholarly journals Observed and predicted ages at peak height velocity in soccer players

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254659
Author(s):  
Robert M. Malina ◽  
Manuel J. Coelho-e-Silva ◽  
Diogo V. Martinho ◽  
Paulo Sousa-e-Siva ◽  
Antonio J. Figueiredo ◽  
...  
Keyword(s):  
Peak Height ◽  
Soccer Players ◽  
Height Velocity ◽  
Leg Length ◽  
Peak Height Velocity ◽  
Sitting Height ◽  
Early Maturing ◽  
Central Portugal ◽  
Offset Time ◽  
Age Range

The purpose of the study was to evaluate predicted maturity offset (time before age at PHV) and age at PHV (chronological age [CA] minus maturity offset) in a longitudinal sample of 58 under-13 club level soccer players in central Portugal for whom ages at PHV were estimated with the SITAR model. Two maturity offset prediction equations were applied: the original equation which requires CA sitting height, estimated leg length, height and weight, and a modified equation which requires CA and height. Predicted maturity offset increased, on average, with CA at prediction throughout the age range considered, while variation in predicted maturity offset and ages at PHV within CA groups was considerably reduced compared to variation in observed ages at offset and at PHV. Predicted maturity offset and ages at PHV were consistently later than observed maturity offset and age at PHV among early maturing players, and earlier than observed in late maturing players. Both predicted offset and ages at PHV with the two equations were, on average, later than observed among players maturing on time. Intra-individual variation in predicted ages at PHV with each equation was considerable. The results for soccer players were consistent with similar studies in the general population and two recent longitudinal studies of soccer players. The results question the utility of predicted maturity offset and age at PHV as valid indicators of maturity timing and status.

Growth, Maturation, and Exercise

2015 ◽  
Vol 27 (1) ◽  
pp. 3-7
Author(s):  
Jaak Jürimäe
Keyword(s):  
Peak Height ◽  
Height Velocity ◽  
Chronological Age ◽  
Leg Length ◽  
Peak Height Velocity ◽  
Male Youth ◽  
Youth Athletes ◽  
Sitting Height ◽  
Early Maturing ◽  
Mean Differences

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 programs.

Assessment of Growth and Maturation in Female Athletes at a Single Point in Time

2014 ◽  
Vol 22 (2) ◽  
pp. 76-82 ◽  
Author(s):  
Jennifer L. Gay ◽  
Eva V. Monsma ◽  
Alan L. Smith ◽  
J.D. DeFreese ◽  
Toni Torres-McGehee
Keyword(s):  
Discriminant Validity ◽  
Female Athletes ◽  
Single Point ◽  
Peak Height ◽  
Height Velocity ◽  
Chronological Age ◽  
Age At Menarche ◽  
Peak Height Velocity ◽  
Anthropometric Measures ◽  
Shared Variance

Growth and maturation may impact adolescent behavior and development of psychological disorders. Currently age at menarche is used as the primary marker of maturation, even though it occurs later than other indicators of growth such as peak height velocity (PHV). Maturity offset predicting age at PHV has not been validated in diverse samples. Anthropometric measures and self-reported age at menarche were obtained for 212 female athletes ages 11 to 16 years (M = 13.25). Shared variance between menarcheal age and estimated age at PHV (APHV) was small (R2 = 5.3%). Discriminant validity was established by classifying participants as pre- or post-PHV or menarche (X2 = 32.62, P < .0001). The Pearson’s correlation between chronological age and age at PHV (r = .69) was stronger than with age at menarche (r = .26). Making informed decisions about accounting for growth and maturation using estimated age at PHV are offered.

scholarly journals Reliability of the Spatiotemporal Determinants of Maximal Sprint Speed in Adolescent Boys Over Single and Multiple Steps

2015 ◽  
Vol 27 (3) ◽  
pp. 419-426 ◽  
Author(s):  
Robert W. Meyers ◽  
Jon L. Oliver ◽  
Michael G. Hughes ◽  
Rhodri S. Lloyd ◽  
John Cronin
Keyword(s):  
Contact Time ◽  
Optical Measurement ◽  
Pairwise Comparison ◽  
Step Length ◽  
Height Velocity ◽  
Adolescent Boys ◽  
Step Frequency ◽  
Peak Height Velocity ◽  
Sprint Speed ◽  
Length Step

The purpose of this study was to examine the reliability of the spatiotemporal determinants of maximal sprinting speed in boys over single and multiple steps. Fifty-four adolescent boys (age = 14.1 ± 0.7 years [range = 12.9–15.7 years]; height = 1.63 ± 0.09 m; body mass = 55.3 ± 13.3 kg; -0.31 ± 0.90 age from Peak Height Velocity (PHV) in years; mean ± s) volunteered to complete a 30 m sprint test on 3 occasions over a 2-week period. Speed, step length, step frequency, contact time, and flight time were assessed via an optical measurement system. Speed and step characteristics were obtained from the single-fastest step and average of the 2 and 4 fastest consecutive steps. Pairwise comparison of consecutive trials revealed the coefficient of variation (CV) for speed was greater in 4-step (CV = 7.3 & 7.5%) compared with 2-step (CV = 4.2 & 4.1%) and 1-step (CV = 4.8 & 4.6%) analysis. The CV of step length, step frequency and contact time ranged from 4.8 to 7.5% for 1-step, 3.8–5.0% for 2-step and 4.2–7.5% for 4-step analyses across all trials. An acceptable degree of reliability was achieved for the spatiotemporal and performance variables assessed in this study. Two-step analysis demonstrated the highest degree of reliability for the key spatiotemporal variables, and therefore may be the most suitable approach to monitor the spatiotemporal characteristics of maximal sprint speed in boys.

scholarly journals Breakfast: A Crucial Meal for Adolescents’ Cognitive Performance According to Their Nutritional Status. The Cogni-Action Project

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1320
Author(s):  
Humberto Peña-Jorquera ◽  
Valentina Campos-Núñez ◽  
Kabir P. Sadarangani ◽  
Gerson Ferrari ◽  
Carlos Jorquera-Aguilera ◽  
...  
Keyword(s):  
Nutritional Status ◽  
Cognitive Performance ◽  
Cognitive Demand ◽  
Positive Association ◽  
Peak Height ◽  
The Body ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
High Quality ◽  
Action Project

This study aimed to determine whether pupils who have breakfast just before a cognitive demand, do not regularly skip breakfast, and consume a high-quality breakfast present higher cognitive performance than those who do not; furthermore, to establish differences according to their nutritional status. In this study, 1181 Chilean adolescents aged 10–14 years participated. A global cognitive score was computed through eight tasks, and the body mass index z-score (BMIz) was calculated using a growth reference for school-aged adolescents. The characteristics of breakfast were self-reported. Analyses of covariance were performed to determine differences in cognitive performance according to BMIz groups adjusted to sex, peak height velocity, physical fitness global score, and their schools. A positive association was found in adolescents’ cognitive performance when they had breakfast just before cognitive tasks, did not regularly skip breakfast, presented at least two breakfast quality components, and included dairy products. No significant differences were found between breakfast components, including cereal/bread and fruits/fruit juice. Finally, pupils who were overweight/obese who declared that they skipped breakfast regularly presented a lower cognitive performance than their normal-BMIz peers. These findings suggest that adolescents who have breakfast just prior to a cognitive demand and regularly have a high quality breakfast have better cognitive performance than those who do not. Educative nutritional strategies should be prioritized, especially in “breakfast skippers” adolescents living with overweight/obesity.

scholarly journals Growth in achondroplasia, from birth to adulthood, analysed by the JPA-2 model

2020 ◽  
Vol 33 (12) ◽  
pp. 1589-1595
Author(s):  
Mariana del Pino ◽  
Virginia Fano ◽  
Paula Adamo
Keyword(s):  
General Population ◽  
Growth Curve ◽  
Growth Velocity ◽  
Adult Height ◽  
Growth Curves ◽  
Peak Height ◽  
Height Growth ◽  
Individual Growth ◽  
Height Velocity ◽  
Peak Height Velocity

AbstractObjectivesIn general population, there are three phases in the human growth curve: infancy, childhood and puberty, with different main factors involved in their regulation and mathematical models to fit them. Achondroplasia children experience a fast decreasing growth during infancy and an “adolescent growth spurt”; however, there are no longitudinal studies that cover the analysis of the whole post-natal growth. Here we analyse the whole growth curve from infancy to adulthood applying the JPA-2 mathematical model.MethodsTwenty-seven patients, 17 girls and 10 boys with achondroplasia, who reached adult size, were included. Height growth data was collected from birth until adulthood. Individual growth curves were estimated by fitting the JPA-2 model to each individual’s height for age data.ResultsHeight growth velocity curves show that after a period of fast decreasing growth velocity since birth, with a mean of 9.7 cm/year at 1 year old, the growth velocity is stable in late preschool years, with a mean of 4.2 cm/year. In boys, age and peak height velocity in puberty were 13.75 years and 5.08 cm/year and reach a mean adult height of 130.52 cm. In girls, the age and peak height velocity in puberty were 11.1 years and 4.32 cm/year and reach a mean adult height of 119.2 cm.ConclusionsThe study of individual growth curves in achondroplasia children by the JPA-2 model shows the three periods, infancy, childhood and puberty, with a similar shape but lesser in magnitude than general population.

Sign in / Sign up

Export Citation Format

Share Document