Effects of Acute Caffeine Consumption on Sodium-Aided Hyperhydration

Abstract

When utilized separately, pre-exercise hyperhydration or consumption of caffeine have both been shown to be ergogenic. Acute caffeine consumption has also been shown to promote diuresis in some situations, but this effect has not been studied when caffeine is used in conjunction with sodium-aided hyperhydration. We measured urine production during hyperhydration strategies performed with and without caffeine. Fifteen euhydrated subjects performed five strategies by consuming 20 mL water/kg bm alone (NT), or with a placebo (PL), 5 mg/kg bm caffeine (Caf), 110 mg/kg bm NaCl (Na), or 5 mg caffeine +110 mg NaCl/kg bm (CafNa). Total urine excretion was measured for 2 h following treatment consumption and expressed as a percentage of the total water consumed. Total twohour urine excretion values were 103 16% (NT), 102 15% (PL), 116 18% (Caf), 68 14% (Na) and 85 14% (CafNa) of water consumed. No significant difference in urine excretion was detected between NT and PL. Caf resulted in significantly more, and Na in significantly less, urine excretion compared to all other strategies. CafNa resulted in significantly less urine excretion than NT, PL, and Caf, but significantly more excretion than Na. The results suggest that hyperhydration can be achieved when an acute caffeine dose is consumed in conjunction with sodium-aided hyperhydration; however, the level of hyperhydration is significantly less than attained when an equal dose of water and sodium are consumed without caffeine.