scholarly journals Low Doses of Caffeine: Enhancement of Physical Performance in Elite Adolescent Male Soccer Players

2019 ◽  
Vol 14 (5) ◽  
pp. 569-575 ◽  
Author(s):  
Matthew Ellis ◽  
Mark Noon ◽  
Tony Myers ◽  
Neil Clarke

Context: High doses of ∼6 mg·kg−1 body mass have improved performance during intermittent running, jumping, and agility protocols. However, there are sparse data on low doses of caffeine, especially in elite adolescent soccer players. Methods: A total of 15 elite youth soccer players (177.3 [4.8] cm, 66.9 [7.9] kg, and 16 [1] y) participated in the study, consuming 1, 2, or 3 mg·kg−1 caffeine in a gelatin capsule or a 2-mg·kg−1 placebo in a single-blind, randomized, crossover study design. Testing consisted of a 20-m sprint, arrowhead agility (change of direction [CoD] right or left), countermovement jump (CMJ), and Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1). Postexercise CMJ performance was assessed as participants exited the Yo-Yo IR1. Data were analyzed using a Bayesian multilevel regression model to provide explained variance and probabilities of improvement (P = %). Results: Compared with placebo, 3 mg·kg−1 caffeine presented the highest probabilities of change across a range of tests (mean [SD], P = %). Times for 20-m sprint were 3.15 (0.10) s vs 3.18 (0.09) s (P = 73%), CoD-right times were 8.43 (0.24) s vs 8.55 (0.25) s (P = 99%), CoD-left times were 8.44 (0.22) s vs 8.52 (0.18) s (P = 85%), Yo-Yo IR1 distance was 2440 (531) m vs 2308 (540) m (P = 15%), and preexercise CMJ height was 41.6 (7.2) cm vs 38 (8.5) cm (P = 96%). Postexercise CMJ was higher with 3 mg·kg−1 than with placebo (42.3 [8] cm vs 36.6 [8] cm; P = 100%). Doses of 1 or 2 mg·kg−1 caffeine also demonstrated the ability to enhance performance but were task dependent. Conclusion: Low doses of caffeine improve performance but are dose and task dependent. A dose of 3 mg·kg−1 caffeine improved performance across the majority of tests with potential to further improve postexercise CMJ height.

Author(s):  
Björn Kadlubowski ◽  
Michael Keiner ◽  
Tobias Stefer ◽  
Andreas Kapsecker ◽  
Hagen Hartmann ◽  
...  

AbstractChange of direction (COD) performance has an essential role in soccer. In the literature, there is a wide range of explained variance in correlation analyses between linear-sprint performance, concentric power and maximum strength and COD performance. Therefore this study has (1) analyzed the influence of linear-sprint performance, concentric power and maximum strength on COD performance in elite youth soccer players and (2) compared the calculated influence on the different COD tests. To answer the research questions, 67 elite youth soccer players were tested. The linear-sprint (10 m, [LS]) performance, concentric power (squat jump [SJ]) and maximum strength (1 repetition maximum [1 RM]) and COD (measured via the Illinois agility test [IAT], the 505 agility test [505], the agility test of the German Soccer Association [GewT], and the triangle test [TriT]) were assessed. The Pearson correlation analysis was used to assess the relationship. Benjamini and Hochberg’s method, which was used to control the study-wise false discovery rate, was 0.05. The LS performance had the greatest impact on COD performance with a wide range of explained variance between the different COD tests (r2 = 0.18 to 0.39). However, SJ compared to LS performance had lower influence, but also a wide range of explained variance (r2 = −0.02 to −0.29). Correlations for 1 RM and COD test were calculated with r2 = −0.01 to −0.09. Thus, (1) the greater the similarity between the performance tests (i.e., LS, SJ, 1 RM) and the COD tests, the higher the explained variance between the variables in question. Furthermore, (2) as the different COD tests are affected to different degrees by linear-sprint, concentric power and maximum strength performance, it might be concluded that the tests have a different physiological requirement profile. Therefore, coaches and sport scientists must review and select different tests with logical validity, based on the requirement profiles of soccer.


2021 ◽  
Vol 12 ◽  
Author(s):  
Dorsaf Sariati ◽  
Raouf Hammami ◽  
Hassane Zouhal ◽  
Cain C. T. Clark ◽  
Ammar Nebigh ◽  
...  

Background: Change-of-direction (CoD) is a necessary physical ability of a field sport and may vary in youth players according to their maturation status.Objectives: The aim of this study is: to compare the effectiveness of a 6-week CoD training intervention on dynamic balance (CS-YBT), horizontal jump (5JT), speed (10 and 30-m linear sprint times), CoD with (15 m-CoD + B) and without (15 m-CoD) the ball, in youth male soccer players at different levels of maturity [pre- and post-peak height velocity (PHV)].Materials and Methods: Thirty elite male youth soccer players aged 10–17 years from the Tunisian first division participated in this study. The players were divided into pre- (G1, n = 15) and post-PHV (G2, n = 15) groups. Both groups completed a similar 6-week training program with two sessions per week of four CoD exercises. All players completed the following tests before and after intervention: CS-YBT; 5 JT; 10, 30, and 15 m-CoD; and 15 m-CoD + B, and data were analyzed using ANCOVA.Results: All 30 players completed the study according to the study design and methodology. Adherence rate was 100% across all groups, and no training or test-related injuries were reported. Pre-PHV and post-PHV groups showed significant amelioration post-intervention for all dependent variables (after test > before test; p < 0.01, d = 0.09–1.51). ANOVA revealed a significant group × time interaction only for CS-YBT (F = 4.45; p < 0.04; η2 = 0.14), 5JT (F = 6.39; p < 0.02; η2 = 0.18), and 15 m-CoD (F = 7.88; p < 0.01; η2 = 0.22). CS-YBT, 5JT, and 15 m-CoD improved significantly in the post-PHV group (+ 4.56%, effect size = 1.51; + 4.51%, effect size = 1.05; and -3.08%, effect size = 0.51, respectively), more than the pre-PHV group (+ 2.77%, effect size = 0.85; + 2.91%, effect size = 0.54; and -1.56%, effect size = 0.20, respectively).Conclusion: The CoD training program improved balance, horizontal jump, and CoD without the ball in male preadolescent and adolescent soccer players, and this improvement was greater in the post-PHV players. The maturity status of the athletes should be considered when programming CoD training for soccer players.


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.


Sports ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 149
Author(s):  
Michael Keiner ◽  
Andreas Kapsecker ◽  
Tobias Stefer ◽  
Björn Kadlubowski ◽  
Klaus Wirth

The aim of this investigation was to analyze significant differences in performance depending on the level of play (elite vs. amateur) in youth soccer players (under 17 years. old (U17) and U19). A cross-sectional study was conducted, and 45 elite and amateur male youth soccer players (16.56 ± 0.9 years old) were evaluated in their performances in squat jump (SJ), 10 m linear sprint (LS), 20 m LS, 505 agility test (505) and Illinois agility test (IAT). Differences in performances were analyzed with a 2 × 2 MANOVA, post-hoc ANOVAs, and Hedges’ g (g) for pairwise comparisons of subgroups (level of play and age group). This investigation showed that the elite player performance was significantly (p < 0.05) better in all performance tests than amateur players in both age groups. Interestingly, this investigation showed that the more complex the target exercise, the larger the effect sizes for group differences (SJ: g = 0.64–1.18, LS: g = 0.05–2.23, change-of-direction (COD): g = 3.01–6.84). The SJ, LS, 505, and IAT may prove useful in talent selection test batteries to separate between competitive levels in youth soccer players.


2014 ◽  
Vol 5 (2) ◽  
pp. 1-12
Author(s):  
Gunnar Elling Mathisen

Abstract Acceleration, sprint and agility performance are crucial in sports like soccer. There are few studies regarding the effect of training on youth soccer players in agility performance and in sprint distances shorter than 30 meter. Therefore, the aim of the recent study was to examine the effect of a high-intensity sprint and plyometric training program on 13-year-old male soccer players. A training group of 14 adolescent male soccer players, mean age (±SD) 13.5 years (±0.24) followed an eight week intervention program for one hour per week, and a group of 12 adolescent male soccer players of corresponding age, mean age 13.5 years (±0.23) served as control a group. Pre- and post-tests assessed 10-m linear sprint, 20-m linear sprint and agility performance. Results showed a significant improvement in agility performance, pre 8.23 s (±0.34) to post 7.69 s (± 0.34) (p<0.01), and a significant improvement in 0-20m linear sprint, pre 3.54s (±0.17) to post 3.42s (±0.18) (p<0.05). In 0-10m sprint the participants also showed an improvement, pre 2.02s (±0.11) to post 1.96s (± 0.11), however this was not significant. The correlation between 10-m sprint and agility was r = 0.53 (p<0.01), and between 20-m linear sprint and agility performance, r = 0.67 (p<0.01). The major finding in the study is the significant improvement in agility performance and in 0-20 m linear sprint in the intervention group. These findings suggest that organizing the training sessions with short-burst high-intensity sprint and plyometric exercises interspersed with adequate recovery time, may result in improvements in both agility and in linear sprint performance in adolescent male soccer players. Another finding is the correlation between linear sprint and agility performance, indicating a difference when compared to adults.


Sports ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 111 ◽  
Author(s):  
Björn Kadlubowski ◽  
Michael Keiner ◽  
Hagen Hartmann ◽  
Klaus Wirth ◽  
Ulrich Frick

Change of direction (COD) is a performance-limiting factor in team sports. However, there are no exact definitions describing which physical abilities limit COD performance in soccer. Nevertheless, different COD tests are used or have been recommended as being equally effective in the professional practice of measuring COD performance. Therefore, the aim of this study was to evaluate the relationship between different COD tests, and to test the independence and generalizability of these COD tests in soccer. As such, 27 elite youth soccer players were randomly recruited and were tested in different COD tests (i.e., Illinois agility test (IAT), T agility test (TT), 505 agility test (505), Gewandtheitslauf (GewT), triangle test (Tri-t), and square test (SQT)). Bivariate Pearson correlation analysis was used to assess the relationships between the COD tests. The Benjamini–Hochberg method was used to control for the false discovery rate of the study at 0.05. This investigation calculated explained variances of 10% to 55% between performances in the different COD tests. This suggested that the tests covered different aspects or task-specific characteristics of the COD. Therefore, coaches and sport scientists should review and select different tests with a logical validity, based on the requirement profiles of the corresponding sport.


2014 ◽  
Vol 9 (6) ◽  
pp. 1006-1012 ◽  
Author(s):  
Dieter Deprez ◽  
Joao Valente-dos-Santos ◽  
Manuel Coelho e Silva ◽  
Matthieu Lenoir ◽  
Renaat M. Philippaerts ◽  
...  

Purpose:To model the development of soccer-specific aerobic performance, assessed by the Yo-Yo Intermittent Recovery Test Level 1 in 162 elite pubertal soccer players, age 11–14 y at baseline.Methods:Longitudinal multilevel modeling analyses comprised predictors related to growth (chronological age, body size [height and weight] and composition [fat mass, fat-free mass]), and motor coordination [3 Körperkoordination Test für Kinder subtests: jumping sideways, moving sideways, backward balancing] and estimated biological-maturation groups (earliest [>percentile 33] and latest maturers [>percentile 66]).Results:The best-fitting model on soccer-specific aerobic performance could be expressed as –3639.76 + 369.86 × age + 21.38 × age2 + 9.12 × height – 29.04 × fat mass + 0.06 × backward balance. Maturity groups had a negligible effect on soccer-specific aerobic performance (–45.32 ± 66.28; P > .05).Conclusion:The current study showed that the development of aerobic performance in elite youth soccer is related to growth and muscularity and emphasized the importance of motor coordination in the talentidentification and -development process. Note that biological maturation was excluded from the model, which might endorse the homogeneity in estimated biological-maturation status in the current elite pubertal soccer sample.


2018 ◽  
Author(s):  
Moisés Arturo Cabrera Hernández ◽  
Luis Javier Tafur Tascon ◽  
Daniel Dylan Cohen ◽  
Sergio Andrés García-Corzo ◽  
Alexander Quiñonez Sánchez ◽  
...  

2010 ◽  
Vol 32 (4) ◽  
pp. 555-579 ◽  
Author(s):  
James W. Adie ◽  
Joan L. Duda ◽  
Nikos Ntoumanis

Grounded in the 2 × 2 achievement goal framework (Elliot & McGregor, 2001), the purpose of this study was to investigate the temporal relationships between achievement goals, competition appraisals and indices of psychological and emotional welfare among elite adolescent soccer players. A subsidiary aim was to ascertain the mediational role of competition appraisals in explaining the potential achievement goal and well-/ill-being relationships. Ninety-one boys (mean age = 13.82 years) involved in an elite soccer program completed multisection questionnaires capturing the targeted variables. Measures were obtained on five occasions across two competitive seasons. Multilevel regression analyses revealed that MAp goals positively, and MAv goals negatively, predicted within-person changes in well-being over two seasons. PAp goal adoption was positively associated to within-person changes in negative affect. PAv goals corresponded negatively to between-person mean differences in positive affect. The results of the indirect effects showed challenge appraisals accounted for within-person associations between a MAp goal focus and well- and ill-being over time. The present findings provide only partial support for the utility of the 2 × 2 achievement goal framework in predicting young athletes’ psychological and emotional functioning in an elite youth sport setting.


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