Pre-exercise hyperhydration appears to acutely increase plasma volume which may reduce heart rate and core temperature during constant work rate exercise to exhaustion compared with control.

Implementing pre-exercise hyperhydration may induce gastrointestinal symptoms during exercise in some individuals, with the severity of symptoms potentially associated with the dose, timing and ingestion rate of the hyperhydration strategy.

The effect of hyperhydration on time-trial performance is equivocal and provides an area for future research.