Comparative effects of selected non-caffeinated rehydration sports drinks on short-term performance following moderate dehydration

Background: the effect of moderate dehydration and consequent fluid replenishment on short-duration maximal treadmill performance was studied in eight healthy,fit (vo2max= 49.7 ± 8.7 ml kg-1min-1) males aged 28 ± 7.5 yrs.methods: the study involved a within subject,blinded,crossover,placebo design. initially,all subjects performed a baseline exercise test using an individualized treadmill protocol structured to induce exhaustion in 7 to 10 min. on each of the three subsequent testing days,the subjects exercised at 70-75% vo2maxfor 60 min at 29-33°c,resulting in a dehydration weight loss of 1.8-2.1% body weight. after 60 min of rest and recovery at 22 c,subjects performed the same treadmill test to voluntary exhaustion,which resulted in a small reduction in vo2maxand a decline in treadmill performance by 3% relative to the baseline results. following another 60 min rest and recovery,subjects ingested the same amount of fluid lost in the form of one of three lemon-flavored,randomly assigned commercial drinks,namely crystal light (placebo control),gatorade®and rehydrate electrolyte replacement drink,and then repeated the treadmill test to voluntary exhaustion.results: vo2maxreturned to baseline levels with rehydrate,while there was only a slight improvement with gatorade and crystal light. there were no changes in heart rate or ventilation with all three different replacement drinks. relative to the dehydrated state,a 6.5% decrease in treadmill performance time occurred with crystal light,while replenishment with gatorade,which contains fructose,glucose,sodium and potassium,resulted in a 2.1% decrease. in contrast,treatment with rehydrate,which comprises fructose,glucose polymer,calcium,magnesium,sodium,potassium,amino acids,thiols and vitamins,resulted in a 7.3% increase in treadmill time relative to that of the dehydrated state.conclusions: the results indicate that constituents other than water,simple transportable monosaccharides and sodium are important for maximal exercise performance and effective recovery associated with endurance exercise-induced dehydration. © 2010 snell et al; licensee biomed central ltd.