Study Preview
Study Title and Description
Independent and combined effects of carbohydrate and caffeine ingestion on aerobic cycling performance in the fed state.
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 | Independent and combined effects of carbohydrate and caffeine ingestion on aerobic cycling performance in the fed state. |
Author | TL Acker-Hewitt,BM Shafer,MJ Saunders,Q Goh,ND Luden, |
Country | |
Year | 2012 |
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 this study was to examine the independent and combined effects of carbohydrate and caffeine ingestion on performance and various physiological parameters during aerobic cycling (about 1 hour). | ||
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) | The 4 treatments were (i) placebo (PLA) trial: placebo pill administered 60 min prior to exercise, and artificially sweetened water (250 mL) administered at the following 3 time points during the exercise trial: immediately prior to exercise, following the 20-min SS (steady state), and 20 min into the TT (time trial); (ii) carbohydrate- only (CHO) trial: placebo pill administered 60 min prior to exercise, and a carbohydrate solution (20 g carbohydrate, 8% solution, 250 mL fluid) administered at the 3 aforementioned time points; (iii) caffeine-only (CAF) trial: 6-mg/kg body weight dose of commercially available anhydrous caffeine (TerraVita; in pill form) administered 60 min prior to exercise, and a placebo solution containing artificially sweetened water (250 mL) administered at the 3 time points; and (iv) caffeine and carbohydrate (CAF-CHO) trial: 6-mg·kg–1 body weight caffeine pill administered 60 min prior to exercise, and a carbohydrate solution (20 g carbohydrate, 8% solution, 250 mL fluid) administered at the 3 time points. Heart rate (HR) (Polar, Lake Success, N.Y., USA) and rating of perceived exertion (RPE) (Borg scale) were recorded in the eighth minute of the 20-min SS segment and with 0.05 km remaining in the 20-km TT. | ||
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? | NCT | ||
What were the diagnostics or methods used to measure the outcome? | Objective | ||
Optional: Name of Method or short description | Heart rate (HR) (Polar, Lake Success, N.Y., USA) and rating of perceived exertion (RPE) (Borg scale) were recorded in the eighth minute of the 20-min SS (steady state) segment and with 0.05 km remaining in the 20-km TT (time trial). | ||
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.) | placebo vs. caffeine treatment | ||
What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods) | Duration and mean power output (W) for the 20-km TT, HR, RPE, RER, blood glucose, decline in MVC (pre- to postexercise), and blood lactate were assessed using repeated- measures analyses of variance (ANOVA), with treatment as a within-subjects factor. A 2 x 4 (time x treatment) repeated-measures ANOVA was used to assess pre- and postexercise MVC. Further, planned comparisons for both TT performance and mean power output were identified a priori and included each treatment compared with PLA. All pairwise comparisons were performed using dependent t tests with a Bonferroni correction. Friedman tests were applied to the following parameters that were not normally distributed: V O2, VE, RPE, post-TT glucose, and lactate. Pairwise comparisons were performed using Wilcoxon’s signed Rank Tests. The a priori level of significance was set at p < 0.05. All data are reported as means +/- SD. | ||
What conflicts of interest were reported? | Not discussed. | ||
Refid | 22436075 | ||
What were the sources of funding? | Not discussed. |
Results & Comparisons
No Results found.