Study Preview
Study Title and Description
Caffeine supplementation and reactive agility in elite youth soccer players.
Key Questions Addressed
1 | For [population], is caffeine intake above [exposure dose], compared to intakes [exposure dose] or less, associated with adverse effects on cardiovascular outcomes? |
Primary Publication Information
Title | Caffeine supplementation and reactive agility in elite youth soccer players. |
Author | JB Jordan,A Korgaokar,RS Farley,JM Coons,JL Caputo, |
Country | |
Year | 2014 |
Numbers |
Secondary Publication Information
There are currently no secondary publications defined for this study.
Extraction Form: Cardiovascular Design
Question... Follow Up | Answer | Follow-up Answer | |
---|---|---|---|
What outcome is being evaluated in this paper? | Cardiovascular | ||
What is the objective of the study (as reported by the authors)? | 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. | ||
Provide a general description of the methods as reported by the authors. Information should be extracted based on relevance to the SR (i.e., caffeine related methods) | A 3-day notice was given to participants before testing days. A list of dietary sources of caffeine was provided and participants were asked to refrain from caffeine use for 24 hr before each day of testing. This 24-hr period served as the washout period from caffeine usage. Participants were also asked to refrain from consumption of food or beverage within 1 hr of testing. Using a randomized, counter-balanced, doubleblind, repeated-measures experimental design, participants completed 4 days of testing on the RAT. Day 1 was to familiarize the participants to the testing protocol. Day 2 was to establish a baseline to evaluate the placebo and caffeine’s effects on the RAT. Days 3 and 4 were the experimental trials in which the participants randomly received either a gelatin filled capsule with caffeine (6 maltodextrin; NOW Sports, Carbo Gain) 1 hr before testing which served as the wash-in period. A 1-hr wash-in period was chosen because the literature indicates caffeine’s peak blood serum levels are reached in this time frame (23). Randomization to the condition was accomplished using an Internet-based randomization program (Research Randomizer). The treatment was reversed in day 4 for a counterbalanced design. To control for diurnal variation, each player was tested at the same time of the day (7 p.m.) with 48 hrs of recovery between each testing session. HR was recorded using HR monitors (Polar Electro, Model F1 A1), 1 hr after taking the supplement (or resting HR for the baseline testing), immediately before the start of the test, and at the conclusion of testing immediately following the 3 trials of the RAT. | ||
How many outcome-specific endpoints are evaluated? | 1 | ||
What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately) | Heart rate. | ||
List additional health endpoints (separately). 2 | |||
List additional health endpoints (separately).3 | |||
List additional health endpoints (separately).4 | |||
List additional health endpoints (separately).5 | |||
List additional health endpoints (separately).6 | |||
Clinical, physiological, other | Physiological | ||
What is the study design? | Controlled Trial | ||
Randomized or Non-Randomized? | RCT | ||
What were the diagnostics or methods used to measure the outcome? | Objective | ||
Optional: Name of Method or short description | HR was recorded using HR monitors (Polar Electro, Model F1 A1), 1 hr after taking the supplement (or resting HR for the baseline testing), immediately before the start of the test, and at the conclusion of testing immediately following the 3 trials of the RAT. | ||
Caffeine (general) | Caffeine (general) | ||
Coffee, Chocolate, energy drink, gum, medicine/supplement, soda, tea, other? | |||
Measured or self reported? | Measured | ||
Children, adolescents, adults, or pregnant included? | Adolescents | ||
What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.) | Caffeine vs. placebo (plus exercise) | ||
What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods) | Differences among the baseline, caffeine, and placebo conditions on fastest RT (dominant, nondominant), fastest ST (Dominant, Non-Dominant), and fastest TT to complete the agility test (dominant, nondominant) were analyzed using 6 one-way repeated measures analysis of variance (RMANOVA) through a multivariate analysis of variance (MANOVA) approach. Within each day of testing (baseline, caffeine, placebo), only the fastest conditions and the correct reactive decisions to the dominant and nondominant side were used in data analyses. Differences among the baseline, caffeine, and placebo conditions on RPE after the warm-up and at the conclusion of the test were analyzed using 2 one-way RMANOVA through a MANOVA approach. Differences among the baseline, caffeine, and placebo conditions on HR 1 hr after taking the supplement, before starting the test, and at the conclusion of the test were analyzed using 3 one-way RMANOVA through a MANOVA approach. A post hoc test using a Bonferroni adjustment was used to determine the direction of significance if significance was found in the original analysis. Mauchly’s Test of Sphericity was used to test for violations in the assumption of sphercity. Intraclass correlations using Cronbach’s Alpha were analyzed using the two-way mixed design. Predictive analytics software (IBM SPSS, Version 21.0) with an alpha level of .05 was used for all analyses to control the familywise error rate. | ||
What conflicts of interest were reported? | The authors have no professional relationships with companies or manufacturers who will benefit from the results of this study, and the results of this study do not constitute endorsement of the product by the authors. | ||
Refid | 24277927 | ||
What were the sources of funding? | There was no grant funding for this study. |
Results & Comparisons
No Results found.