The importance of water in the normal functioning of our bodies is no understatement. Proper hydration is required to be happy and healthy. Athlete’s have a larger demand for fluid intake – not just for thermo- and salt regulation; but evidently, also for performance.
In a 2007 study, participants were either euhydrated, or dehydrated by either 2.5% or 5% body weight using exercise-heat stress and manipulating fluid intake. Following dehydration, participants conducted numerous physical tasks to measure strength, power and resistance exercise performance.
Interestingly, it appeared that levels of dehydration did not modulate vertical height jump, jump squat power, isometric squat force or measured capacity to activate quadriceps (i.e. central activation ratio (CAR)). However, what was impaired, was the subjects capacity to conduct the same amount of reps compared to baseline during a back squat protocol.
There were significant decrements in relative number of repetitions during sets 2 and 3 in both groups of dehydrated participants compared to euhydrated participants. Moreover, there was a significant decrement in relative repetitions during sets 4-5 between 5% dehydrated and euhydrated participants.
Taken together, these data indicate that in order to maintain workload volume and exercise intensity during bouts of resistance training, it is essential to sustain optimal levels of hydration.
Cheuvront S. N., et al. Fluid banace and endurance exercise performance. Curr. Sports. Med. Rep.:2003:2(4):202-8.
Judelson D. A., et al. Effect of Hydration State on Strength, Power, and Resistance Exercise Performance. Med. Sci. Sports Exerc.:2007:39(10):1817-1824.