Fluid, electrolyte, and renal indices of hydration during 11 days of controlled caffeine consumption
journal contribution
posted on 2023-05-17, 12:43authored byArmstrong, LE, Pumerantz, AC, Roti, MW, Judelson, DA, Greig Watson, Dias, G, Sokmen, B, Casa, DJ, Maresh, CM
This investigation determined if 3 levels of controlled caffeine consumption affected fluid-electrolyte balance and renal function differently. Healthy males (mean +/- standard deviation; age, 21.6 +/- 3.3 y) consumed 3 mg caffeine . kg(-1) . d(-1). on days 1 to 6 (equilibration phase). On days 7 to 11 (treatment phase), subjects consumed either 0 mg (C0; placebo; n= 20), 3 mg (C3; n = 20), or 6 mg (C6; n = 19) caffeine . kg(-1) . d(-1) in capsules, with no other dietary caffeine intake. The following variables were unaffected (P > 0.05) by different caffeine doses on days 1, 3, 6, 9, and 11 and were within normal clinical ranges: body mass, urine osmolality, urine specific gravity, urine color, 24-h urine volume, 24-h Na+ and K+ excretion, 24-h creatinine, blood urea nitrogen, serum Na+ and K+, serum osmolality, hematocrit, and total plasma protein. Therefore, C0, C3, and C6 exhibited no evidence of hypohydration. These findings question the widely accepted notion that caffeine consumption acts chronically as a diuretic.
History
Publication title
International Journal of Sport Nutrition and Exercise Metabolism
Volume
2005 Jun
Issue
15(3)
Pagination
252-65
ISSN
1526-484X
Department/School
School of Health Sciences
Publisher
Champaign, IL : Human Kinetics Publishers, c2000
Place of publication
United States
Repository Status
Restricted
Socio-economic Objectives
Evaluation of health and support services not elsewhere classified