Study Preview
Study Title and Description
The effect of caffeine ingestion on 8 km run performance in a field setting.
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 | The effect of caffeine ingestion on 8 km run performance in a field setting. |
Author | CA Bridge,MA Jones, |
Country | |
Year | 2006 |
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)? | The purpose of the present study was to investigate the effect of caffeine ingestion on 8 km run performance using an ecologically valid test protocol. | ||
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) | Participants Eight trained male distance runners who had competed regularly for over 2 years participated in this study. The participants’ mean (+/- s) physical characteristics were as follows: age 21.3 +/- 1.2 years, body mass 69.3+/- 5.0 kg, height 1.78 +/- 0.08m. All participants were habitual users of caffeine and had no history of hypersensitivity to caffeine. Nutritional status and training control Nutritional status was controlled for 24 h before each race. In addition, the participants were instructed to refrain from caffeine consumption, alcohol consumption and to keep training intensity and duration light in the 48 h before all trials. They were also instructed to arrive at each race in a fully hydrated state. Experimental Design Each participant was required to complete an 8 km race as quickly as possible while competing against each other. The experiment was a randomized double-blind crossover design, which involved repeated measures of the same participants. Three trials in total were performed, each separated by one week and each was conducted at the same time of day. Experimental Protocol The participants were instructed to report to the laboratory 2 ½ h before experimental testing, when resting measurements of heart rate and blood lactate concentration were taken. The participants then ingested a placebo capsule containing 3mg/kg body mass of glucose, a caffeine capsule containing 3mg/kg body mass (AnalaR caffeine, VWR International Ltd) or no supplement (control), 1 h before each race. After administration, the participants were instructed to rest quietly for 1 h. One hour post-ingestion, resting heart rate and blood lactate concentration were re-measured. The participants were then allowed an active warm up and stretching period and were instructed to reproduce the same preparation for each trial. The participants were instructed to compete in an 8 km race on a standard synthetic track against each other in the fastest possible time. Heart rate was recorded at 5 s intervals throughout the race (Polar team system, interfaced using Polar precision performance software version 4.0). Statistical Analysis One-way repeated-measures analyses of variance (ANOVA) were conducted to evaluate the influence of treatment (3 levels) on mean race heart rate. Two-way repeated-measures (treatment x time) ANOVA was conducted for 5min mean heart rates during the race. Significance was set at P < 0.05. When significant treatment effects were identified, related t -tests were conducted to allow pair-wise comparison between treatments, and the significance level was adjusted using the Bonferroni correction for the number of comparisons. All statistical procedures were performed using SPSS for Windows, version 11.5. Descriptive data are expressed as the mean +/- standard deviation (s). | ||
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 | Heart rate was recorded at 5 s intervals throughout the race (Polar team system, interfaced using Polar precision performance software version 4.0). | ||
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? | Adults | ||
What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.) | Subjects served as their own controls (placebo and no treatment) | ||
What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods) | None | ||
What conflicts of interest were reported? | No information provided | ||
Refid | 16492607 | ||
What were the sources of funding? | No information provided |
Results & Comparisons
No Results found.