scholarly journals Running Performance and Hormonal, Maturity and Physical Variables in Starting and Non-Starting Elite U14 Soccer Players During a Congested Match Schedule

2021 ◽  
Vol 80 (1) ◽  
pp. 287-295
Author(s):  
Vinicius Zanetti ◽  
Marcelo Saldanha Aoki ◽  
Paul Bradley ◽  
Christopher Carling ◽  
Thomas Kisil Marino ◽  
...  

Abstract This study examined changes in match running performance (MRP) in Under-14 soccer players (13.5 ± 0.7 yrs) during a congested match schedule (CMS) (4 matches played within a 5-day period). It also examined the difference in salivary testosterone (sT) concentration, somatic maturation, jumping tests, and Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1) between the players selected to play (SLG; group who participated in all matches) and players non-selected to play (NSG). A significant difference was observed for the frequency of decelerations (DEC) across matches (match 4 vs. matches 1, 2 and 3; p = 0.05; partial ƞ2 = 0.20). No difference between matches was observed for total running distance (TRD), high-speed running distance (HSRD), and frequency of accelerations (ACC) (p > 0.05). A wide range for within-player coefficient of variation (CV) values was observed for all MRP variables (range: 10.5 = TRD to 30.6 = HSRD). No difference between SLG and NSG for any of the assessed variables was observed (p > 0.05). The findings suggest that DEC was the most pertinent variable for monitoring changes in MRP during the CMS. In addition, at an elite youth soccer level, the biological maturity and fitness might not influence selection to play.

Author(s):  
James Parr ◽  
Keith Winwood ◽  
Emma Hodson-Tole ◽  
Frederik J.A. Deconinck ◽  
James P. Hill ◽  
...  

Purpose: To investigate the influence of maturation on match running performance in elite male youth soccer players. Methods: A total of 37 elite male youth soccer participants from an English professional soccer academy from the U14s, U15s, and U16s age groups were assessed over the course of 1 competitive playing season (2018–2019). Relative biological maturity was assessed using percentage of predicted adult height. A global positioning system device was used between 2 and 30 (mean = 8 [5]) times on each outfield player. The position of each player in each game was defined as defender, midfielder, or attacker and spine or lateral. A total of 5 match-running metrics were collected total distance covered, high-speed running distance, very high-speed running distance, maximum speed attained, and number of accelerations. Results: Relative biological maturity was positively associated with all global positioning system running metrics for U14s. The U15/16s showed variation in the associations among the global positioning system running metrics against maturity status. A multilevel model which allowed slopes to vary was the best model for all parameters for both age groups. In the U14 age group, advanced maturation was associated with greater high-speed running distance. However, maturation did not contribute toward variance in any of the indices of running performance in the U15/16s. In the U15/16 age group, significance was observed in the spine/lateral playing positions when undertaking actions that required covering distance at high speeds. Conclusions: Maturation appeared to have an impact on match-running metrics within the U14s cohort. However, within the U15/16s, the influence of maturation on match-running metrics appeared to have less of an impact.


Author(s):  
Carlos Lago-Peñas ◽  
Anton Kalén ◽  
Miguel Lorenzo-Martinez ◽  
Roberto López-Del Campo ◽  
Ricardo Resta ◽  
...  

This study aimed to evaluate the effects playing position, match location (home or away), quality of opposition (strong or weak), effective playing time (total time minus stoppages), and score-line on physical match performance in professional soccer players using a large-scale analysis. A total of 10,739 individual match observations of outfield players competing in the Spanish La Liga during the 2018–2019 season were recorded using a computerized tracking system (TRACAB, Chyronhego, New York, USA). The players were classified into five positions (central defenders, players = 94; external defenders, players = 82; central midfielders, players = 101; external midfielders, players = 72; and forwards, players = 67) and the following match running performance categories were considered: total distance covered, low-speed running (LSR) distance (0–14 km · h−1), medium-speed running (MSR) distance (14–21 km · h−1), high-speed running (HSR) distance (>21 km · h−1), very HSR (VHSR) distance (21–24 km · h−1), sprint distance (>24 km · h−1) Overall, match running performance was highly dependent on situational variables, especially the score-line condition (winning, drawing, losing). Moreover, the score-line affected players running performance differently depending on their playing position. Losing status increased the total distance and the distance covered at MSR, HSR, VHSR and Sprint by defenders, while attacking players showed the opposite trend. These findings may help coaches and managers to better understand the effects of situational variables on physical performance in La Liga and could be used to develop a model for predicting the physical activity profile in competition.


2010 ◽  
Vol 150-151 ◽  
pp. 1063-1067
Author(s):  
Fei Fei Zhu ◽  
Zhi Li Zhong ◽  
Zong Fu Guo

The three composite boards which were made of continuous basalt fiber (CBF) and polypropylene fiber (PP) in different fiber ratios were researched on this paper. The manufacturing forming process included blending, carding, web formation, laminating and compression molding orderly. The tension and bending properties were investigated experimentally, and then dual variance analysis was used to show the significant difference of the mechanical property in the transverse and longitudinal orientation as well the appreciable impact of different fiber ratios to the mechanical property. The results show that the difference of the tension and blending strength in the same direction, among composite boards in different fiber proportions, is about 1~10Mpa; the difference in the same fiber proportion, between transverse and longitudinal, vary within a wide range from 10Mpa to 30Mpa. The results of variance analysis have also proved the conclusion, the difference between transverse and longitudinal is more significant than the difference among different fiber proportions. In the similar study, the significance hadn’t been seen sufficiently, so this paper provides reference to the actual application of the composite board.


Author(s):  
Dr. Syed Kamaruzaman Syed Ali

The purpose of this study was to investigate the difference of cardiovascular endurance between secondary school soccer players and handball players. The study adopted ex-post facto design. The subjects were selected among soccer and handball players at one of the secondary schools. A total of 60 subjects were selected, 30 soccer players and 30 handball players. All subjects aged between 13 and 15 years old. The test used to test cardiovascular endurance was 12 minute Cooper Run Test. T-test was used to determine whether there is a significant difference between the cardiovascular endurance of the soccer players and handball players. The results of the study showed that there was no significant difference t(-1.65)=58, P>0.05 between soccer players (M = 2235; SD = 180.44) and handball players (M = 2307.83; SD = 160.19). Although there was no significant difference, the players from both teams still have good cardiovascular endurance fitness.


2016 ◽  
Vol 11 (6) ◽  
pp. 819-824 ◽  
Author(s):  
Brad S Keller ◽  
Annette J Raynor ◽  
Lyndell Bruce ◽  
Fiona Iredale

Objectives To determine whether the technical ability of Australian youth soccer players could distinguish between various playing levels. Design A cross-sectional observational design was used with each player required to complete four technical tests. Methods Sixty-two participants were representatives of three cohorts of youth soccer in Australia: national elite ( n = 18), state elite ( n = 22) and sub-elite ( n = 22). The technical tests used were Loughborough Short Passing Test (LSPT), long passing test (LPT), shooting test and speed dribbling, with all players familiarised with the tests prior to data collection. Differences between cohorts were analysed using a multiple analysis of variance test with follow-up analyses of variance and Tukey Honest Significant Difference post-hoc test, which were subsequently used to inform a sensitivity analysis, more specifically a bootstrapped receiver operating curve to determine cut-off scores for each variable. Results The national elite cohort scored better than state- and sub-elite cohorts on the LSPT, however, the state elite produced the fastest time before penalties. The sub-elite cohort scored less points on the LPT compared to both national- and state-elite cohorts, on both feet. In regards to speed dribbling, national-elite players were faster than both the state- and sub-elite cohorts. Shooting accuracy and velocity were able to discriminate the national- and sub-elite cohorts on the dominant foot, with shooting velocity on the nondominant foot being faster for the national elite compared to both the state- and sub-elite cohorts. Conclusions A number of differences in technical ability were identified between varying levels of Australian youth soccer players. Youth soccer coaches and sports scientists should use the cut-off scores for the technical tests in the talent identification and development process, with aspiring players aiming to reach these levels.


2019 ◽  
Vol 24 (4) ◽  
Author(s):  
Anderson Santiago Teixeira ◽  
Juliano Fernandes da Silva ◽  
Priscila Cristina dos Santos ◽  
Paulo Cesar do Nascimento Salvador ◽  
Fernando de Souza Campos ◽  
...  

2017 ◽  
Vol 30 (4) ◽  
pp. 439-444 ◽  
Author(s):  
Ester Del Duca ◽  
Francesca Farnetani ◽  
Nathalie De Carvalho ◽  
Ugo Bottoni ◽  
Giovanni Pellacani ◽  
...  

Psoriasis is a chronic inflammatory skin disease affecting 2%–3% of the population. The wide range of drugs currently available for its treatment could be associated, in the long term, with organ toxicity and adverse events, thus, clinical monitoring throughout treatment is required. This investigator-initiated trial (IIT) evaluated the efficacy and the safety of a vitamin B12-containing ointment in comparison with glycerol-petrolatum-based emollient cream used twice a day to treat mild-to-moderate plaque psoriasis for a period over 12 weeks followed by a wash-out observation period of 4 weeks. This study was conducted as a randomized, controlled, single-blind, intra-patient left- to right-side trial comparing the efficacy and safety of vitamin B12-containing ointment (M-treatment) with a glycerol-petrolatum-based emollient cream (C-treatment). The Psoriasis Area Severity Index (PASI) was determined at baseline (T0), at time points T2 (14 days), T4 (4 weeks), T8 (8 weeks), T12 (12 weeks) and 4 weeks after the end of the wash-out period (F1). In total, 24 patients with plaque psoriasis were randomized to receive left- or right-side treatment with B12 ointment. From time point T2 to time point F1, there was a statistically significant difference in PASI reduction between M-treatment side and C-treatment side. At time point T 12, the difference between the mean reductions from baseline PASI scores by 5.92 ± 2.49 (87, 6%) in the M-treatment side versus 1.08 ± 1.02 (23, 1%) C-treatment side was statistically highly significant ( PWex < 0.001). On the contemporary panorama in the treatment of psoriasis, we conclude that vitamin B12 ointment will represent a new concrete therapy option and should be considered in the update of therapeutic algorithm for the treatment of psoriasis


2015 ◽  
Vol 40 (9) ◽  
pp. 907-917 ◽  
Author(s):  
Adam J. Wells ◽  
Jay R. Hoffman ◽  
Kyle S. Beyer ◽  
Mattan W. Hoffman ◽  
Adam R. Jajtner ◽  
...  

The management of playing time in National Collegiate Athletic Association (NCAA) soccer athletes may be a key factor affecting running performance during competition. This study compared playing time and running performance between regular-season and postseason competitions during a competitive women’s soccer season. Nine NCAA Division I women soccer players (age, 21.3 ± 0.9 years; height, 170.3 ± 5.7 cm; body mass, 64.0 ± 5.8 kg) were tracked using portable GPS devices across 21 games during a competitive season (regular season (n = 17); postseason (n = 4)). Movements on the field were divided into operationally distinct thresholds defined as standing/transient motion, walking, jogging, low-speed running, moderate-speed running, high-speed running, sprinting, low-intensity running, and high-intensity running. A significant increase in minutes played (+17%, p = 0.010) was observed at postseason compared with the regular season. Concomitant increases in time spent engaged in low-intensity running (LIR: +18%, p = 0.011), standing/transient motion (+35%, p = 0.004), walking (+17%, p = 0.022), distance covered while walking (+14%, p = 0.036), and at low intensity (+11%, p = 0.048) were observed. Performance comparisons between the first and second half within games revealed a significant decrease (p ≤ 0.05) in high-speed and high-intensity runs during the second half of the postseason compared with the regular season. Changes in minutes played correlated significantly with changes in absolute time spent engaged in LIR (r = 0.999, p < 0.001), standing/transient motion (r = 0.791, p = 0.011), walking (r = 0.975, p = 0.001), jogging (r = 0.733, p = 0.025), distance covered while walking (r = 0.898, p < 0.001) and low-intensity activity (r = 0.945, p < 0.001). Negative correlations were observed between minutes played and absolute time sprinting (r = −0.698, p = 0.037) and distance covered sprinting (r = −0.689, p = 0.040). Results indicate that additional minutes played during the postseason were primarily performed at lower intensity thresholds, suggesting running performance during postseason competitions may be compromised with greater playing time in intercollegiate women’s soccer.


2013 ◽  
Vol 22 (2) ◽  
pp. 100-107 ◽  
Author(s):  
Jacqueline Vieira de Castro ◽  
Karina Costa Machado ◽  
Kelly Scaramussa ◽  
João Luiz Ellera Gomes

Context:After years of focusing on the management of anterior cruciate ligament (ACL) injuries, the most common soccer-related injuries, the orthopedic community has concluded that soccer players have a wide range of variation in joint biomechanics and has thus started to focus research efforts on the morphological factors that might contribute to ACL trauma. One such factor is decreased hip-rotation range of motion (ROM), which may be due to compensatory musculoskeletal changes occurring in response to longstanding soccer practice since childhood.Objective:This study sought to assess decreased hip rotation and the influence of stretching exercises on the behavior of the hip joint in players of the youth soccer categories of a Brazilian soccer team.Design:Randomized clinical trial.Setting:University hospital.Patients:262 male soccer players.Interventions:Subjects were randomly allocated into 2 groups—control or a stretching program.Main Outcome Measures:Subjects were reassessed after 12 wk.Results:The findings suggest that hip-rotation ROM decreases over the years in soccer players. In the study sample, adherence to a stretching program improved only external hip-rotation ROM in the nondominant limb.Conclusion:Playing soccer can restrict rotation ROM of the hip, and adherence to stretching exercises may decrease the harmful effects on the hip joints.


2014 ◽  
Vol 42 (1) ◽  
pp. 103-111 ◽  
Author(s):  
Michael R. Esco ◽  
Ronald L. Snarr ◽  
Andrew Flatt ◽  
Matthew Leatherwood ◽  
Adam Whittaker

Abstract The purpose of this study was to determine if the HRindex Method (VO2max = [6 x HRindex - 5] x 3.5, where HRindex = HRmax/HRrest) was accurate for tracking changes in VO2max following 8-weeks of endurance training among collegiate female soccer players. Predicted VO2max via the HRindex Method and observed VO2max from a maximal exercise test on a treadmill were determined for a group of female soccer athletes (n = 15) before and following an 8-week endurance training protocol. The predicted (pVO2max) and observed (aVO2max) values were compared at baseline and within 1-week post-training. Change values (i.e., the difference between pre to post) for each variable were also determined and compared. There was a significant difference between aVO2max before (43.2 ± 2.8 ml.kg.min-1) and following (46.2 ± 2.1 ml.kg.min-1) the 8-week training program (p < 0.05). However, pVO2max did not significantly change following training (pre = 43.4 ± 4.6 ml.kg.min-1, post = 42.9 ± 4.1 ml.kg.min-1, p = 0.53). Furthermore, the correlation between the change in aVO2max and the change in pVO2max was trivial and non-significant (r = 0.30, p = 0.28). The HRindex Method does not appear to be suitable for predicting changes in VO2max following 8-weeks of endurance training in female collegiate soccer players


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