Role of Free Testosterone in Interpreting Physical Performance in Elite Young Brazilian Soccer Players

2013 ◽  
Vol 25 (2) ◽  
pp. 186-197 ◽  
Author(s):  
Alexandre Moreira ◽  
Arnaldo Mortatti ◽  
Marcelo Aoki ◽  
Ademir Arruda ◽  
Camila Freitas ◽  
...  
Keyword(s):  
Physical Performance ◽  
Body Mass ◽  
Linear Regression Analysis ◽  
Free Testosterone ◽  
Multiple Linear Regression Analysis ◽  
Soccer Players ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
Salivary Testosterone ◽  
Significant Difference

This study investigated the contribution of salivary testosterone (sT) concentration, years from peak height velocity (YPHV) and height by body mass interaction on jumping performance (Countermovement jump; CMJ) and aerobic fitness (Yo-Yo intermittent endurance test, level 1) in young elite soccer players. Forty-five participants (age: 12.5 ± 0.5y; body mass: 48.6 ± 10.2kg, height: 155.7 ± 10.0cm) belonging to a top level Brazilian soccer club were evaluated at four time points across a single semester. None of the assessed players had reached PHV. The data from the four evaluations were averaged and multiple linear regression analysis conducted. For CMJ, the model explained 42.88% of the variance (R2 = 42.88; p < .000); sT concentration was the primary contributor (R2 = 32.84) and the YPHV contributed 9.95% of the variance. The model explained 28.50% (p < .000) of the variance in Yo-Yo. The sT was the primary and single significant contributor (R2 = 21.32). A significant difference was noted between high and low testosterone groups divided a posteriori to CMJ performance (t = 3.35; p = .001). These results suggest an important role for hormonal status in interpreting physical performance in preadolescent soccer players.

scholarly journals Does Resisted Sled Towing Improve the Physical Qualities of Elite Youth Soccer Players of Differing Maturity Status?

2021 ◽  
Author(s):  
Rhys Morris ◽  
Tony Myers ◽  
Stacey Emmonds ◽  
Dave Singleton ◽  
Kevin Till
Keyword(s):  
Body Mass ◽  
Bayesian Regression ◽  
Soccer Players ◽  
Height Velocity ◽  
Regression To The Mean ◽  
Peak Height Velocity ◽  
Maturity Group ◽  
Youth Soccer ◽  
Professional Soccer ◽  
The Impact

Abstract Purpose Sled towing has been shown to be an effective method to enhance the physical qualities in youth athletes. The aim of this study was to evaluate the impact of a 6-week sled towing intervention on muscular strength, speed and power in elite youth soccer players of differing maturity status. Method Seventy-three male elite youth soccer players aged 12–18 years (Pre-Peak Height Velocity [PHV] n = 25; Circa-PHV n = 24; Post-PHV n = 24) from one professional soccer academy participated in this study. Sprint assessments (10 m and 30 m), countermovement jump and isometric mid-thigh pull were undertaken before (T1) and after (T2) a 6-week intervention. The training intervention consisted of 6 weeks (2 × per week, 10 sprints over 20 m distance) of resisted sled towing (linear progression 10%–30% of body mass) during the competitive season. Bayesian regression models analysed differences between T1 and T2 within each maturity group. Results There were minimal changes in strength, speed and power (P = 0.35–0.80) for each maturity group across the 6-week intervention. Where there were changes with greater certainty, they are unlikely to represent real effect due to higher regression to the mean (RTM). Conclusion It appears that a 6-week sled towing training programme with loadings of 10%–30% body mass only maintains physical qualities in elite youth soccer players pre-, circa-, and post-PHV. Further research is required to determine the effectiveness of this training method in long-term athletic development programmes.

Is the Relationship Between Sprinting and Maximal Aerobic Speeds in Young Soccer Players Affected by Maturation?

2010 ◽  
Vol 22 (4) ◽  
pp. 497-510 ◽  
Author(s):  
Alberto Mendez-Villanueva ◽  
Martin Buchheit ◽  
Sami Kuitunen ◽  
Tsz Kit Poon ◽  
Ben Simpson ◽  
...  
Keyword(s):  
Body Mass ◽  
Allometric Scaling ◽  
Young Male ◽  
Peak Height ◽  
Soccer Players ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
Positive Correlations ◽  
The Relationship

The purpose of this study was to investigate the relationship between maximal sprinting (MSS) and aerobic (MAS) speeds in a cohort of highly-trained young male soccer players with the influence of body mass controlled for using allometric scaling. MSS and MAS were obtained in 14 pre-age at peak height velocity (APHV) players (12.3 ± 0.7 years), 21 circum-APHV players (14.3 ± 0.9 year) and 26 post-APHV players (16.9 ± 0.7 years). The three groups showed similar positive correlations between MSS and MAS (r = 0.73 to 0.52; p < .01). In conclusion, our results suggest that the relationship between MSS and MAS is not affected by maturation.

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.

Does Predicted Age At Peak Height Velocity Explain Physical Performance In U13-15 Basketball Female Players?

2021 ◽  
Author(s):  
Karol Gryko ◽  
Jakub Grzegorz Adamczyk ◽  
Anna Kopiczko ◽  
Jorge Lorenzo Calvo ◽  
Alberto Lorenzo Calvo ◽  
...  
Keyword(s):  
Physical Fitness ◽  
Physical Performance ◽  
Body Mass ◽  
Body Height ◽  
Height Velocity ◽  
Stepwise Multiple Regression ◽  
Peak Height Velocity ◽  
Basketball Players ◽  
Basic Body ◽  
The Relationship

Abstract Background: The aims of the study were (i) to identify the physical fitness and basic anthropometric characteristics of Polish female basketball players aged 13 to 15 years, (ii) to show the effect of maturity timing on the performance in motor tests and basic body composition parameters, (iii) to identify the index that contributes most to the prediction of performance in the tests of speed, jumping ability, agility, and endurance. Methods: The sample included 925 female Polish players (U13-15). In part 1, maturity timing category distribution were examined within across age-groups. In part 2, the relationship between the anthropometric variables, physical fitness performance was assessed based on maturity timing categories (ANCOVA analysis). In part 3, backward stepwise multiple regression analyse quantified the relationship between maturity timing (group of PHV) and physical performance.Results: ANCOVA results (age, body height, and body mass as covariates) showed in the U13 female basketball players significantly higher sprinting (20m), jumping ability and endurance tests results of the PHV1 group.Better results was observed in U14 female players in PHV1 compared to PHV2 and PHV3 in 20m and jumping tests but opposite trend was observed for 5m sprint and endurance test (distance covered and VO2max). U15 basketball players from the PHV3 group were characterized by better results of jumping abilities, endurance, 10m and 20m sprint and agility (total, S4) tests. Maturity timing (10m), chronological age (5 m, 20 m, agility, SVJ, VJ, and VO2max tests), body height (10m), body mass (10m, 20m, VJ, VO2max), and the interaction between body mass and height (SVJ) were significant (adjusted R2 = 0.02-0.10; p < 0.001) predictors of motor skills. Conclusion: The results can help the coaches to personalize training programs and to adapt the training content to the biological age of the players.

The relationship between peak height velocity and physical performance in youth soccer players

2006 ◽  
Vol 24 (3) ◽  
pp. 221-230 ◽  
Author(s):  
Renaat M. Philippaerts ◽  
Roel Vaeyens ◽  
Melissa Janssens ◽  
Bart Van Renterghem ◽  
Dirk Matthys ◽  
...  
Keyword(s):  
Physical Performance ◽  
Peak Height ◽  
Soccer Players ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
Youth Soccer ◽  
The Relationship

scholarly journals Age-related differences in linear sprint in adolescent female soccer players

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Elena Mainer-Pardos ◽  
Oliver Gonzalo-Skok ◽  
Hadi Nobari ◽  
Demetrio Lozano ◽  
Jorge Pérez-Gómez
Keyword(s):  
Body Mass ◽  
Peak Height ◽  
Sprint Performance ◽  
Soccer Players ◽  
Height Velocity ◽  
Adolescent Female ◽  
Peak Height Velocity ◽  
Running Speed ◽  
Biological Maturation ◽  
Age Related

Abstract Background Several studies have observed the contribution of chronological age, biological maturation, and anthropometric characteristics to sprinting performance in young soccer players. Nevertheless, there are no studies that have analysed the contribution of these characteristics to running speed qualities in adolescent female soccer players. Objective This study investigated age-related differences in sprint performance in adolescent female soccer players. Also, it examined the possible influence of anthropometry [body mass and body mass index (BMI)] and biological maturation [age at peak height velocity (APHV)] in sprint performance. Methods Eighty adolescent female soccer players [under (U) 14, n = 20; U16, n = 37; U18, n = 23] participated in this study. Players were tested for 40 m sprint (each 10 m split times). Results Posthoc analysis revealed better performance in all split sprint times of older soccer players (U18 and U16) compared with younger category (F: 3.380 to 6.169; p < 0.05; ES: 0.64 to 1.33). On the contrary in all split sprint times, there were no significant changes between U16 and U18 (p < 0.05; ES: 0.03 to 0.17). ANCOVA revealed differences in all parameters between groups, controlled for APHV (p < 0.05). In contrast, all between-group differences disappeared after body mass and BMI adjustment (p > 0.05). Finally, the results indicate that BMI and body mass were significantly correlated with 40 m sprint (p < 0.05; r: -0.31) and 20 m flying (p < 0.01; r: 0.38), respectively. Conclusion In the present players’ sample, body mass and BMI had a significant impact on running speed qualities.

Effects of 6 Weeks Resistance Training Combined With Plyometric and Speed Exercises on Physical Performance of Pre-Peak-Height-Velocity Soccer Players

2016 ◽  
Vol 11 (2) ◽  
pp. 240-246 ◽  
Author(s):  
David Rodríguez-Rosell ◽  
Felipe Franco-Márquez ◽  
Fernando Pareja-Blanco ◽  
Ricardo Mora-Custodio ◽  
Juan M. Yáñez-García ◽  
...  
Keyword(s):  
Resistance Training ◽  
Strength Training ◽  
Physical Performance ◽  
Peak Height ◽  
Sprint Performance ◽  
Soccer Players ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
Low Load ◽  
Low Volume

Purpose:To analyze the effects of low-load, high-velocity resistance training (RT) combined with plyometrics on physical performance in pre-peak-height-velocity (PHV) soccer players.Methods:Thirty young soccer players from the same academy were randomly assigned to either a strength training (STG, n = 15) or a control group (CG, n = 15). Strength training consisted of full squat exercise with low load (45–58% 1RM) and low volume (4–8 repetitions/set) combined with jumps and sprints twice a week over 6 wk of preseason. The effect of the training protocol was assessed using sprint performance over 10 and 20 m, countermovement jump, estimated 1-repetition maximum, and average velocity attained against all loads common to pre- and posttests in full squat.Results:STG showed significant improvements (P = .004–.001) and moderate to very large standardized effects (ES = 0.71–2.10) in all variables measured, whereas no significant gains were found in CG (ES = –0.29 to 0.06). Moreover, significant test × group interactions (P < .003–.001) and greater between-groups ESs (0.90–1.97) were found for all variables in favor of STG compared with CG.Conclusion:Only 6 wk of preseason low-volume and low-load RT combined with plyometrics can lead to relevant improvements in strength, jump, and sprint performance. Thus, the combination of field soccer training and lightweight strength training could be used for a greater development of the tasks critical to soccer performance in pre-PHV soccer players.

scholarly journals Injury Risk and Injury Burden Are Related to Age Group and Peak Height Velocity Among Talented Male Youth Soccer Players

2018 ◽  
Vol 6 (12) ◽  
pp. 232596711881104 ◽  
Author(s):  
Hans Jan Bult ◽  
Maarten Barendrecht ◽  
Igor Joeri Ramon Tak
Keyword(s):  
Injury Risk ◽  
Age Groups ◽  
Peak Height ◽  
Soccer Players ◽  
Height Velocity ◽  
Incidence Density ◽  
Chronological Age ◽  
Peak Height Velocity ◽  
The Mean ◽  
Injury Burden

Background: The relationship between injury risk (IR) in age groups and periods around peak height velocity (PHV) remains unclear. PHV is defined as the moment of the largest increase in body height. Purpose: To investigate injury risk and injury burden as functions of growth velocity (periods around PHV) and chronological age groupings (under 12 years [U12] to U19) in talented youth male soccer players. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 170 players from the youth academy of a Dutch soccer club (highest professional league: Eredivisie) were observed for 1 to 3 seasons. Injuries, exposure, PHV age, and chronological age were registered. The injury incidence density (IID) and injury burden per 1000 hours of soccer participation, with 95% CIs, were calculated for 5 PHV periods and 7 age groups. These were compared with the overall cohort results using incidence ratios (IRs) and burden ratios (BRs) with 95% CIs. Results: The mean age at PHV was 14.4 ± 0.65 years (range, 12.8-16.5 years). The mean IID for the total cohort was 8.34 injuries per 1000 hours (95% CI, 7.71-9.02). Compared with the overall mean, a significantly higher IID was found for PHV period 4+5 (IR, 1.31 [95% CI, 1.00-1.71]; P = .049) and for the U15 group (IR, 1.49 [95% CI, 1.24-1.79]; P < .001). The overall injury burden was 58.37 injury days per 1000 hours (95% CI, 56.66-60.13). In PHV period 4+5, the injury burden was significantly higher (BR, 1.53 [95% CI, 1.39-1.68]; P < .001) when compared with the overall mean. Also, compared with the overall mean, the injury burden was higher in the U16 (BR, 1.48 [95% CI, 1.39-1.58]; P < .001), U15 (BR, 1.28 [95% CI, 1.19-1.38]; P < .001), and U17 groups (BR, 1.21 [95% CI, 1.13-1.31]; P < .001). Conclusion: Talented young soccer players were more prone to injuries during the 6 months after PHV (31% above overall mean) as well as in the U15 group (49% above overall mean). Based on the higher injury burden in the U16 (48%), U15 (28%), and U17 (21%) groups, we suggest that research on injury risk factors and preventive measures should primarily target these age groups. Additional interventions based on PHV may be of limited value from a screening perspective. Further research is needed on the interaction between age groups and PHV periods.

Relationship between fat-to-fat-free mass ratio and decrements in leg strength after downhill running

2001 ◽  
Vol 90 (4) ◽  
pp. 1334-1341 ◽  
Author(s):  
R. C. Hickner ◽  
P. M. Mehta ◽  
D. Dyck ◽  
P. Devita ◽  
J. A. Houmard ◽  
...  
Keyword(s):  
Body Mass ◽  
Muscle Glycogen ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Fat Free Mass ◽  
Mass Ratio ◽  
Low Fat ◽  
Cross Sectional ◽  
Leg Strength ◽  
Downhill Running

The purpose of this study was to determine whether greater body fat mass (FM) relative to lean mass would result in more severe muscle damage and greater decrements in leg strength after downhill running. The relationship between the FM-to-fat-free mass ratio (FM/FFM) and the strength decline resulting from downhill running (−11% grade) was investigated in 24 male runners [age 23.4 ± 0.7 (SE) yr]. The runners were divided into two groups on the basis of FM/FFM: low fat (FM/FFM = 0.100 ± 0.008, body mass = 68.4 ± 1.3 kg) and normal fat (FM/FFM = 0.233 ± 0.020, body mass = 76.5 ± 3.3 kg, P < 0.05). Leg strength was reduced less in the low-fat (−0.7 ± 1.3%) than in the normal-fat individuals (−10.3 ± 1.5%) 48 h after, compared with before, downhill running ( P < 0.01). Multiple linear regression analysis revealed that the decline in strength could be predicted best by FM/FFM ( r2= 0.44, P < 0.05) and FM-to-thigh lean tissue cross-sectional area ratio ( r2= 0.53, P < 0.05), with no additional variables enhancing the prediction equation. There were no differences in muscle glycogen, creatine phosphate, ATP, or total creatine 48 h after, compared with before, downhill running; however, the change in muscle glycogen after downhill running was associated with a higher FM/FFM ( r = −0.56, P < 0.05). These data suggest that FM/FFM is a major determinant of losses in muscle strength after downhill running.

scholarly journals Faktor-Faktor yang Mempengaruhi Keberkesanan Amali Kerja Kayu dari Perspektif Pelajar Sekolah Menengah Vokasional di Provinsi Acheh

2017 ◽  
Vol 9 (1-5) ◽  
Author(s):  
Lailan Fachrah ◽  
Nor Azlina Hasbullah ◽  
Ashah Ab Rahman
Keyword(s):  
Linear Regression Analysis ◽  
Demographic Factors ◽  
Multiple Linear Regression Analysis ◽  
Vocational Schools ◽  
Student Interest ◽  
Security Issues ◽  
Equipment Safety ◽  
Significant Difference ◽  
Hands On ◽  
Stepwise Method

This study aims to identify factors that influence the effectiveness of practical woodworking and determine the effectiveness of practical woodworking from the perspective of students of secondary vocational schools in the province of Aceh. Factors studied were the workshop equipment, safety workshops, teaching skills, the workshop environment and student interest. This study was designed to investigate the significant differences concerning factors woodworking practical effectiveness based on demographic factors. A total of 130 respondents were randomly selected from six vocational schools in the province of Aceh. The instrument consists of a set of questionnaire consisting of 49 items and distributed to second level students. Data analysis using the two types of statistics, namely descriptive statistics and statistical inference. The results showed no significant difference between factors woodworking practical effectiveness based on demographic factors except the income level of parents and the parents of the respondents work. The results of multiple linear regression analysis stepwise method found that only four factors (environmental factors workshops, the students interest, the skills of teachers and workshop equipment factors) that affect the practical effectiveness of woodworking with the correlation coefficient R = 0.779. This shows there is a significant effect of the four factors, the effectiveness of practical woodworking, accounting for 60.6% (R2 = 0.606) changes in the variance in effectiveness of hands-on woodworking, and between the four factors, the workshop environment is the factor that most influences the effectiveness practical woodworking by contributing 43.3% (R2 = 0.433) of the variance in effectiveness of practical woodworking. The main implication of this study is the need for attention from the authorities to be more serious in efforts to improve the facilities and infrastructure in the workshop as well as security issues in practical workshops so that the effectiveness of the woodwork to be more robust.

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