Rehydration with a caffeinated beverage during the nonexercise periods of 3 consecutive days of 2-a-day practices.
The purpose of this study was to assess the influence of rehydration with a caffeinated beverage during nonexercise periods on hydration status throughout consecutive practices in the heat. Ten (7 women, 3 men) partially heat- acclimated athletes (age 24 +/-1y, body fat 19.2 +/- 2 %, weight 68.4 +/- 4.0 kg, height 170 +/- 3 cm) completed 3 successive days of 2-a-day practices (2 h/practice, 4 h/d) in mild heat (WBGT = 23 C). The 2 trials (double-blind, random, cross-over design) included; 1) caffeine (CAF) rehydrated with Coca-Cola and 2) caffeine-free (CF) rehydrated with Caffeine-Free Coca-Cola. Urine and psychological measures were determined before and after each 2-h practice. A significant difference was found for urine color for the post-AM time point, F = 5.526, P = 0.031. No differences were found among other variables (P > 0.05). In summary, there is little evidence to suggest that the use of beverages containing caffeine during nonexercise might hinder hydration status.
Fiala
Kelly A
KA
Department of Kinesiology in the Neag School of Education at the University of Connecticut, Storrs, CT 06269, USA.
Casa
Douglas J
DJ
Roti
Melissa W
MW
D000328:Adult; D000704:Analysis of Variance; D002110:Caffeine / Q000008:administration & dosage* / Q000009:adverse effects / Q000378:metabolism / Q000652:urine; D002253:Carbonated Beverages; D000697:Central Nervous System Stimulants / Q000008:administration & dosage* / Q000009:adverse effects / Q000378:metabolism / Q000652:urine; D018592:Cross-Over Studies; D003681:Dehydration / Q000139:chemically induced / Q000209:etiology / Q000517:prevention & control*; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000187:drug effects; D013046:Specific Gravity; D013997:Time Factors; D016482:Urinalysis
D000697:Central Nervous System Stimulants; D002110:Caffeine