The purpose of this study was to investigate whether the consumption of an ion supply drink is effective for improving the recovery of the plasma volume following exercise-induced dehydration.

A randomized cross-over intervention trial was performed in nine healthy male subjects who were asked to consume an ion supply drink, water, or to not to consume any fluid. The subjects were asked to perform a bicycle exercise in a hot environment with an ambient temperature of 45℃ and a relative humidity of 50% to produce dehydration of 4% of the body mass. During a four-hour recovery period, the subjects were asked to consume the test beverage every 15 minutes 13 separate times, to consume a total amount equal to their body mass loss. Their blood properties were measured over time.

When the ion supply drink was consumed, the recovery of the plasma volume which had decreased due to exercise-induced dehydration recovered significantly faster during the recovery period, namely at 1.5 and 2.5 hours, compared to water, and at 1.5, 2.5, and 4 hours for those who did not consume anything.

The ion supply drink intake contributed to the rapid recovery of the plasma volume following exercise-induced dehydration, thus suggesting that an ion supply drink is useful for ameliorating body fluid loss after sweating during exercise.

Change in plasma volume during the experiment