scholarly journals Metabolic effects of a caffeinated sports drink consumed during a soccer match

2013 ◽  
Vol 19 (4) ◽  
pp. 688-695
Author(s):  
Ana Paula Muniz Guttierres ◽  
Rita de Cássia Alfenas ◽  
Karolina Gatti ◽  
Jorge Roberto Perrout Lima ◽  
Ângela Antunes Silva ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Potassium Concentration ◽  
Plasma Potassium ◽  
Metabolic Effects ◽  
Soccer Players ◽  
Maximum Heart Rate ◽  
Double Blind ◽  
Youth Soccer ◽  
Sports Drink ◽  
Plasmatic Concentration

The purpose of this study was to verify the effect of the intake of a caffeinated sport drink (CAFD) compared to a commercial carbohydrate drink (CHOD) on biochemical parameters and rate of perception exertion in youth soccer players. The experiment was setup in a double-blind crossover design where athletes consumed 5mL.Kg-1 body weight (BW) before the game and 3mL.Kg-1 BW every 15 minutes during the game. Intake of the CAFD resulted in increased blood glucose (BG) and blood lactate (BL) levels and average of maximum heart rate compared to consumption of the CHOD (p = 0.01). No difference was observed in the other variables. CAFD promoted greater plasmatic concentration of BG and BL compared with the CHOD. The CAFD did not increase the mobilization of free fatty acids, did not alter the plasma potassium concentration and was not able to reduce subjective perceived exertion.

Caffeine Supplementation and Reactive Agility in Elite Youth Soccer Players

2014 ◽  
Vol 26 (2) ◽  
pp. 168-176 ◽  
Author(s):  
J. Bradley Jordan ◽  
Ajit Korgaokar ◽  
Richard S. Farley ◽  
John M. Coons ◽  
Jennifer L. Caputo
Keyword(s):  
Repeated Measures ◽  
Perceived Exertion ◽  
Soccer Players ◽  
Ratings Of Perceived Exertion ◽  
Double Blind ◽  
Male Youth ◽  
Warm Up ◽  
Youth Soccer ◽  
Repeated Measures Design ◽  
Reactive Agility

This study examined the effects of caffeine supplementation (6 mg·kg−1) on performance of a reactive agility test (RAT) in 17 elite, male, youth (M = 14 y) soccer players. Using a double-blind, repeated-measures design, players completed 4 days of testing on the RAT after a standardized warm-up. On day 1, anthropometric measurements were taken and players were accommodated to the RAT. On day 2, baseline performance was established. Caffeine or placebo conditions were randomly assigned on day 3 and the condition was reversed on day 4. Players completed 3 randomized trials of the RAT on days 2, 3, and 4 with at least 1 trial to the players’ dominant and nondominant sides. There were no significant differences among conditions in reaction time (RT) to the dominant side, heart rates at any point of measurement, or ratings of perceived exertion (RPE) after completion of the warm-up. Caffeine produced faster RT to the nondominant side (P = .041) and higher RPE at the conclusion of the RAT (P = .013). The effect on the total time (TT) to complete the agility test to the nondominant side approached significance (P = .051). Sprint time and TT to either side did not differ. Caffeine supplementation may provide ergogenic benefit to elite, male, youth soccer players.

scholarly journals Influence of 2D:4D ratio on fitness parameters and accumulated training load in elite youth soccer players

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Hadi Nobari ◽  
Ana Ruivo Alves ◽  
Filipe Manuel Clemente ◽  
Jorge Pérez-Gómez
Keyword(s):  
Body Mass ◽  
Muscular Strength ◽  
Perceived Exertion ◽  
Knee Extensor ◽  
Training Load ◽  
Soccer Players ◽  
Youth Soccer ◽  
Fitness Parameters ◽  
Three Stages ◽  
Left And Right

Abstract Background Digit ratio (2D:4D) characterized by the length of the second digit (2D) divided by the length of the fourth digit (4D), is a powerful marker of athletic performance. Some studies showed a negative correlation between 2D:4D ratio and sports performances. Objectives The purpose of the present study was three-fold: (1) to analyze the influence of anthropometric and 2D:4D ratio on variations of accumulated training load (ATL) and fitness parameters: maximal oxygen uptake (V̇O2max), countermovement jump (CMJ), isometric muscular strength of the knee extensor for hamstring (ISH) and flexor for quadriceps (ISQ) muscles; along three stages of evaluation of soccer players based on playing positions; (2) to analyze the correlations between 2D:4D ratio and aforementioned parameters; and (3) to investigate if variance in fitness levels and ATL can explain the 2D:4D ratio. Methods Twenty-four elite players under 17 years were daily monitored for their rating perceived exertion and ATL across 24 weeks over the season. Soccer players have also measured in three stages for anthropometric traits and fitness parameters. Results Significant differences were observed between playing positions for body mass, goalkeepers had higher body mass compared to centre-midfielder and winger players. Moreover, there were significant differences in ATL between early-season to mid-season in goalkeepers (P = 0.032). The 2D:4D ratio (left and right) shown largely and negatively association with muscular strength (ISQ: r =  − 0.80; r =  − 0.78, P ≤ 0.001, ISH: r =  − 0.63; r =  − 0.62, P = 0.001, respectively) and VO2max changes (r =  − 0.55, P = 0.005; r =  − 0.50, P = 0.013, respectively); lastly, both 2D:4D ratio significantly predicted changes in muscular strength and VO2max in young soccer players. Conclusions Goalkeepers tended to have higher body mass compared to centre-midfielder and winger players; and 2D:4D ratio revealed a mighty predictor of physical fitness changes in soccer players. Evidence should be helpful to professionals to highlight the usefulness of the 2D:4D into the identification of talent, but also to optimize young players' performance.

scholarly journals Comparative Analysis of Load Profile between Small-Sided Games and Official Matches in Youth Soccer Players

Sports ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 173 ◽  
Author(s):  
Carlos Gómez-Carmona ◽  
José Gamonales ◽  
José Pino-Ortega ◽  
Sergio Ibáñez
Keyword(s):  
Heart Rate ◽  
Comparative Analysis ◽  
National Level ◽  
Soccer Players ◽  
Specific Training ◽  
Maximum Heart Rate ◽  
Internal Load ◽  
Youth Soccer ◽  
Low Intensity ◽  
Competition Period

The purposes of the present study are: (a) to characterize the external (eTL) and internal load (iTL) of official matches and small-sided games (SSGs) in relation to their objective, (b) to compare demands between SSG, and (c) to analyze the SSG requirements in relation to official matches during a one-month competition period. Twenty under-18 national-level soccer players were recorded using WIMUTM inertial devices (RealTrack Systems, Almeria, Spain) during four official matches and 12 training sessions where four SSGs with different objectives were performed: (SSG1) keeping the ball; (SSG2) keeping the ball and progressing; (SSG3) keeping the ball, progressing and ending in mini-goals; and (SSG4) keeping the ball, progressing and ending in an official goal with a goalkeeper. Statistical analysis included Kruskall-Wallis’ H and Mann-Whitney’s U with Cohen’s d effect size. The SSGs presented walking and jogging intensity movements (0.7–7 to 7–14 km/h), with a 5-to-8 %HIA (high intensity activity, >16 km/h), where low intensity accelerations, decelerations and impacts were predominant (1–2.5 m/s2; 5–7 G), and %HRMAX (maximum heart rate percentage) was between 70–90%. Only SSG4 presented similar demands to competition, finding differences between SSGs (p < 0.05; d = 1.40 − 0.36). In conclusion, the objective of the SSGs directly influenced the demands on the players in training sessions. For this reason, it is important to monitor demands for designing specific training sessions.

Validity of the Session Rating of Perceived Exertion for Monitoring Exercise Demands in Youth Soccer Players

2015 ◽  
Vol 10 (3) ◽  
pp. 404-407 ◽  
Author(s):  
Jose A. Rodríguez-Marroyo ◽  
Carlos Antoñan
Keyword(s):  
Construct Validity ◽  
Exercise Intensity ◽  
Perceived Exertion ◽  
Current Data ◽  
Rating Of Perceived Exertion ◽  
Soccer Players ◽  
Youth Soccer ◽  
Omni Scale ◽  
The Relationship ◽  
Control Exercise

Purpose:The purpose of this study was to examine the concurrent and construct validity of the Borg (0–10) and children’s OMNI scales for quantifying the exercise intensity and training load (TL) in youth soccer players.Methods:Twelve children (mean ± SD age 11.4 ± 0.5 y, height 154.3 ± 6.5 cm, body mass 39.5 ± 5.4 kg) took part in this study. Exercise intensity and TL were calculated on the basis of the session rating of perceived exertion (sRPE) and heart rate (HR; Edwards method) during 20 technical-tactical training sessions. Players’ sRPEs were obtained from the Borg and OMNI scales.Results:Low correlations between HR-based TL and sRPE TL based on the Borg (r = .17, P = .335) and OMNI (r = .34, P = .007) scales were obtained. Significant (P < .001) relationships in sRPE (r = .76) and TL (r = .79) between RPE scales were found.Conclusion:The current data do not support the relationship between the sRPE and HR methods for quantifying TL in youth soccer players. However, the sRPE method could be considered a better indicator of global internal TL, since sRPE is a measure of both physical and psychological stress. In addition, the authors demonstrated the construct validity for the OMNI scale to control exercise demands.

Caffeinated Sports Drink: Ergogenic Effects and Possible Mechanisms

2007 ◽  
Vol 17 (1) ◽  
pp. 35-55 ◽  
Author(s):  
Kirk J. Cureton ◽  
Gordon L. Warren ◽  
Mindy L. Millard-Stafford ◽  
Jonathan E. Wingo ◽  
Jennifer Trilk ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Strength Loss ◽  
The Other ◽  
Knee Extensors ◽  
Double Blind ◽  
Sports Drink ◽  
Warm Environment ◽  
Interpolated Twitch Technique ◽  
Ergogenic Effects ◽  
Before And After

This double-blind experiment examined the effects of a caffeinated sports drink during prolonged cycling in a warm environment. Sixteen highly trained cyclists completed 3 trials: placebo, carbohydrate-electrolyte sports drink (CES), and caffeinated sports drink (CES+CAF). Subjects cycled for 135 min, alternating between 60% and 75% VO2max every 15 min for the first 120 min, followed by a 15-min performance ride. Maximal voluntary (MVC) and electrically evoked contractile properties of the knee extensors were measured before and after cycling. Work completed during the performance ride was 15–23% greater for CES+CAF than for the other beverages. Ratings of perceived exertion were lower with CES+CAF than with placebo and CES. After cycling, the MVC strength loss was two-thirds less for CES+CAF than for the other beverages (5% vs. 15%). Data from the interpolated-twitch technique indicated that attenuated strength loss with CES+CAF was explained by reduced intrinsic muscle fatigue.

scholarly journals Changes in Injury Risk Mechanisms After Soccer-Specific Fatigue in Male Youth Soccer Players

2018 ◽  
Vol 62 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Michal Lehnert ◽  
Mark De Ste Croix ◽  
Zuzana Xaverova ◽  
Michal Botek ◽  
Renata Varekova ◽  
...  
Keyword(s):  
Injury Risk ◽  
Perceived Exertion ◽  
Metabolic Response ◽  
Body Height ◽  
Soccer Players ◽  
Hamstring Injury ◽  
Match Play ◽  
Male Youth ◽  
Youth Soccer ◽  
Specific Protocol

AbstractThe aim of this study was to examine the acute effects of soccer specific fatigue on muscular and neuromuscular function in male youth soccer players. Elite soccer players (n = 20; age 15.7 ± 0.5 y; body height 177.75 ± 6.61 cm; body mass 67.28 ± 8.29 kg) were measured before and after soccer specific exercise (SAFT90). The reactive strength index (RSI) was determined by a drop jump test, leg stiffness (LS) by a 20 sub-maximal two-legged hopping test, and a functional hamstring to quadriceps strength ratio from isokinetic concentric and eccentric strength of the dominant and non-dominant leg (measured at angular velocities of 1.05 rad · s−1and 3.14 rad · s−1). Metabolic response to the SAFT90was determined by blood lactate and perceived exertion was assessed by the Borg scale. After simulated match play, a significant decrease in absolute LS (t = 4.411; p < 0.001; ω2= 0.48) and relative LS (t = 4.326; p < 0.001; ω2= 0.49) was observed and the RSI increased significantly (t = 3.806; p = 0.001; ω2= 0.40). A reduction in LS found after the SAFT90indicates possible reduction in dynamic knee stabilization. However, if we consider the changes in other observed variables, the present study did not clearly confirm that fatigue induced by a soccer specific protocol increased the risk of ACL and hamstring injury. This may be attributed to the simulated rather than actual match play used in the present study.

scholarly journals The effects of 14-week betaine supplementation on endocrine markers, body composition and anthropometrics in professional youth soccer players: a double blind, randomized, placebo-controlled trial

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Hadi Nobari ◽  
Mehdi Kargarfard ◽  
Vazgen Minasian ◽  
Jason M. Cholewa ◽  
Jorge Pérez-Gómez
Keyword(s):  
Body Composition ◽  
Controlled Trial ◽  
Exercise Program ◽  
Soccer Players ◽  
Double Blind ◽  
Significant Group ◽  
Youth Soccer ◽  
Professional Soccer ◽  
Competitive Season ◽  
Betaine Supplementation

Abstract Objective Betaine supplementation may enhance body composition outcomes when supplemented chronically during an exercise program. The purpose of this study was to evaluate the effect of betaine supplementation on development-related hormones, body composition, and anthropometrics in professional youth soccer players during a competitive season. Methods Twenty-nine players (age, 15.45 ± 0.25 years) were matched based upon position and then randomly assigned to a betaine group (2 g/day; n = 14, BG) or placebo group (PG, n = 15). All subjects participated in team practices, conditioning, and games. If a subject did not participate in a game, a conditioning protocol was used to ensure workload was standardized throughout the 14-week season. Growth hormone (GH), insulin-like growth factor-1 (IGF-1), testosterone, cortisol, height, weight, and body composition were assessed at pre-season (P1), mid-season (P2) and post-season (P3). Anthropometric variables were also measured following a one-year follow-up (F). Results Significant (p < 0.05) group x time interactions were found for testosterone and testosterone to cortisol ratio (T/C). Both variables were greater in BG at P2 and P3 compared to P1, however, the testosterone was less in the PG at P3 compared to P2. There was no significant group by time interactions for GH, IGF-1, lean body mass, or body fat. There was a significant (p < 0.05) group x time interaction in height and weight at F, with the greater increases in BG compared to PG. Conclusion Betaine supplementation increased testosterone levels and T/C ratio in youth professional soccer players during a competitive season. Betaine supplementation had no negative effects on growth (height and weight) and may attenuate reductions in testosterone due to intense training during puberty.

Accumulative Weekly External and Internal Load Relative to Match Load in Elite Male Youth Soccer Players

2021 ◽  
pp. 1-6
Author(s):  
Vicente de Dios-Álvarez ◽  
Pello Alkain ◽  
Julen Castellano ◽  
Ezequiel Rey
Keyword(s):  
Global Positioning System ◽  
High Speed ◽  
Perceived Exertion ◽  
Soccer Players ◽  
Positioning System ◽  
Internal Load ◽  
Male Youth ◽  
Youth Soccer ◽  
Total Distance ◽  
Global Positioning

Purpose: The aim of this study was 2-fold: (1) to assess and compare the external and internal load of elite young soccer players during competitive microcycles and (2) to describe the training/match ratios (TMr) in elite male youth soccer players. Method: Twenty-one youth soccer players were monitored using a 10-Hz global positioning system. Total distance covered, running distance (RD), high-speed RD, sprint distance, number of accelerations and decelerations, player load, and rated perceived exertion were recorded during training sessions and matches. The TMr was calculated for each load measure. All variables were also normalized dividing the load per minute of activity. Results: The RD, high-speed running, and sprint distance were higher 3 days before the match and 2 days before match compared with the rest of the training sessions. However, accelerations, decelerations, and player load were higher 4 days before match than other sessions. Besides this, the TMr of RD, high-speed running, and sprint distance were associated with lower values than the TMr of total distance covered, accelerations, decelerations, and player load. The match constituted the highest load during competitive microcycle. Conclusions: The present data support the idea that youth soccer coaches and practitioners must consider relative training load according to match demands to better manage and evaluate player periodization.

scholarly journals Relationship Between Subjective and External Training Load Variables in Youth Soccer Players

2020 ◽  
pp. 1-7
Author(s):  
Patrick C. Maughan ◽  
Niall G. MacFarlane ◽  
Paul A. Swinton
Keyword(s):  
Principal Component Analysis ◽  
Factor Analysis ◽  
Perceived Exertion ◽  
Principal Component ◽  
Component Analysis ◽  
Training Load ◽  
Soccer Players ◽  
Youth Soccer ◽  
Depth Analysis ◽  
External Training

Purpose: To quantify and describe relationships between subjective and external measures of training load in professional youth soccer players. Methods: Data from differential ratings of perceived exertion (dRPE) and 7 measures of external training load were collected from 20 professional youth soccer players over a 46-week season. Relationships were described by repeated-measures correlation, principal component analysis, and factor analysis with oblimin rotation. Results: Significant positive (.44 ≤ r ≤ .99; P < .001) within-individual correlations were obtained across dRPE and all external training load measures. Correlation magnitudes were found to decrease when training load variables were expressed per minute. Principal component analysis provided 2 components, which described 83.3% of variance. The first component, which described 72.9% of variance, was heavily loaded by all measures of training load, while the second component, which described 10.4% of the variance, appeared to have a split between objective and subjective measures of volume and intensity. Exploratory factor analysis identified 4 theoretical factors, with correlations between factors ranging from .5 to .8. These factors could be theoretically described as objective volume, subjective volume, objective running, and objective high-intensity measures. Removing dRPE measures from the analysis altered the structure of the model, providing a 3-factor solution. Conclusions: The dRPE measures are significantly correlated with a range of external training load measures and with each other. More in-depth analysis showed that dRPE measures were highly related to each other, suggesting that, in this population, they would provide practitioners with similar information. Further analysis provided characteristic groupings of variables.

scholarly journals Variation in the Correlation Between Heart Rate and Session Rating of Perceived Exertion-Based Estimations of Internal Training Load in Youth Soccer Players

2019 ◽  
Vol 31 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Durva Vahia ◽  
Adam Kelly ◽  
Harry Knapman ◽  
Craig A. Williams
Keyword(s):  
Heart Rate ◽  
Confidence Interval ◽  
External Load ◽  
Perceived Exertion ◽  
Training Load ◽  
Rating Of Perceived Exertion ◽  
Soccer Players ◽  
Youth Soccer ◽  
Validity Analysis ◽  
Consistent Method

Purpose: When exposed to the same external load, players receive different internal loads, resulting in varied adaptations in fitness. In adult soccer, internal training load is measured using heart rate (HR) and session rating of perceived exertion (sRPE) scales, but these have been underutilized in youth soccer. This study investigated the in-season variation in correlation between HR and sRPE estimations of training load for adolescent soccer players. Method: Fifteen male professional adolescent players were monitored for 7 months. Within-participant correlations and Bland–Altman agreement plots for HR and sRPE were calculated for each month to analyze variation over the season and for individual players to analyze the validity of the scale. Results: The monthly correlations ranged from r = .60 to r = .73 (P < .05) and the overall correlation was r = .64 (95% confidence interval, .60–.68; P < .001). Bland–Altman plots showed an agreement of methods. Conclusion: Results showed consistently large correlations for all months. sRPE is a consistent method of measure of internal training load for the entire season for youth soccer players. Validity analysis found no bias in sRPE measurements when compared with HR for all players in the study.

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