Welcome to CDC Stacks | Caffeine and diuresis during rest and exercise: A meta-analysis - 37638 | CDC Public Access
Stacks Logo
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.
 
 
Help
Clear All Simple Search
Advanced Search
Caffeine and diuresis during rest and exercise: A meta-analysis
Filetype[PDF - 187.46 KB]


Details:
  • Pubmed ID:
    25154702
  • Pubmed Central ID:
    PMC4725310
  • Funding:
    CC999999/Intramural CDC HHS/United States
  • Document Type:
  • Collection(s):
  • Description:
    Objectives

    Although ergogenic, acute caffeine ingestion may increase urine volume, prompting concerns about fluid balance during exercise and sport events. This meta-analysis evaluated caffeine induced diuresis in adults during rest and exercise.

    Design

    Meta-analysis.

    Methods

    A search of three databases was completed on November 1, 2013. Only studies that involved healthy adults and provided sufficient information concerning the effect size (ES) of caffeine ingestion on urine volume were included. Sixteen studies met the inclusion criteria, providing a total of 28 ESs for the meta-analysis. Heterogeneity was assessed using a random-effects model.

    Results

    The median caffeine dosage was 300 mg. The overall ES of 0.29 (95% confidence interval (CI) = 0.11-0.48, p = 0.001) corresponds to an increase in urine volume of 109 ± 195 mL or 16.0 ± 19.2% for caffeine ingestion vs. non-caffeine conditions. Subgroup meta-analysis confirmed exercise as a strong moderator: active ES = 0.10, 95% CI = −0.07 to 0.27, p = 0.248 vs. resting ES = 0.54, 95% CI = 0.22–0.85, p = 0.001 (Cochran's Q, p = 0.019). Females (ES = 0.75,95% CI = 0.38–1.13, p< 0.001) were more susceptible to diuretic effects than males (ES = 0.13,95% CI = −0.05 to 0.31, p = 0.158) (Cochran's Q, p = 0.003).

    Conclusions

    Caffeine exerted a minor diuretic effect which was negated by exercise. Concerns regarding unwanted fluid loss associated with caffeine consumption are unwarranted particularly when ingestion precedes exercise.