Guidelines for glycerol use in hyperhydration and rehydration associated with exercise
Simon Piet van Rosendal1, Mark Andrew Osborne, Robert Gordon Fassett
1School of Human Movement Studies, The University of Queensland, Brisbane, Queensland, Australia. svanrosendal@hms.uq.edu.au
Sports Medicine (Auckland, N.Z.)
|January 23, 2010
Summary
Glycerol supplementation can help athletes improve hydration status by increasing body water before, during, and after exercise. This enhances endurance capacity and thermoregulation, with minimal side effects.
Area of Science:
- Sports Science
- Human Physiology
- Nutritional Biochemistry
Background:
- Dehydration negatively impacts athletic performance by affecting cardiovascular and thermoregulatory functions.
- Fluid loss exceeding 2% of bodyweight (BW) can inhibit endurance exercise capacity.
- Hyperhydration, or consuming extra fluid before exercise, can mitigate dehydration effects and improve thermoregulation.
Purpose of the Study:
- To analyze the evidence for glycerol's efficacy in facilitating hyperhydration and rehydration in athletes.
- To provide practical guidelines for athletes using glycerol for hydration management.
- To assess the impact of glycerol on body water, exercise capacity, and thermoregulation.
Main Methods:
- Systematic review and analysis of existing studies on glycerol for hyperhydration and rehydration.
- Examination of recommended dosages and timing for glycerol ingestion before, during, and after exercise.
- Evaluation of reported side effects associated with glycerol consumption.
Main Results:
- Glycerol hyperhydration (1.2 g/kg BW in 26 mL/kg BW fluid, 60 min prior to exercise) effectively increases body water and enhances fluid retention.
- Glycerol ingestion during exercise (0.125 g/kg BW in 5 mL/kg BW fluid) can delay dehydration.
- Post-exercise glycerol (1.0 g/kg BW per 1.5 L fluid) aids in accelerating plasma volume restoration.
Conclusions:
- Glycerol supplementation is a viable strategy for endurance athletes to improve hydration status before, during, and after exercise.
- Adherence to specific ingestion protocols can optimize the benefits of glycerol for performance and recovery.
- Potential side effects are rare and generally mild, making glycerol a safe ergogenic aid for hydration.
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