Effects of Caffeine Ingestion on Sodium-Aided Hyperhydration

First Name: 
Nina
Last Name: 
Laughlin
Major Department: 
Exercise Science
Thesis Director: 
David Morris
Date of Thesis: 
May 2014

Volume of urine excreted, volume of fluid retained, and percent of fluid retained was analyzed in four male subjects (24 ± 3 yrs., 70 ± 3.5 kg) who consumed four different treatment strategies during an investigation of the effects of caffeine consumption on sodium-aided hyperhydration. Treatments included: 1. Consumption of 60 mg/kg body mass of NaCl + placebo (aspartame), 2. Consumption of 5 mg/kg body mass of caffeine + placebo, 3. Consumption of 60 mg/kg body mass of NaCl + 5 mg/kg body mass of caffeine, or 4. Consumption of placebos. Each treatment was consumed with 20 mL water/kg body mass and 2 energy bars in a span of thirty minutes, followed by a two hour period in which a bladder void was performed every fifteen minutes. Volume of urine and urine specific gravity (USG) was measured after each void. One-way repeated measures ANOVA were performed to detect differences in total volume of urine excreted and the volume of fluid retained between trials. Analyses revealed a significant difference only between the placebo + placebo treatment and the NaCl + caffeine treatment (p = 0.032, Observed Power = 0.319). Analyses of the percent of fluid retained revealed a significant difference between the placebo + placebo treatment and the sodium + caffeine treatment (p = 0.033, Observed Power = 0.335). Although significant differences were found between certain treatments, Observed Powers of 0.319 and 0.335 suggest that these findings may be due to random chance.