Physiological and performance effects of glycerol hyperhydration and rehydration.
Studies have shown that beverages containing glycerol can enhance and maintain hydration status and may improve endurance exercise performance by attenuating adverse physiological changes associated with dehydration. Improvements to performance include increased endurance time to exhaustion by up to 24%, or a 5% increase in power or work. However, some studies have found no performance benefits during either prolonged exercise or specific skill and agility tests. In studies that have shown benefits, the improvements have been associated with thermoregulatory and cardiovascular changes. These include increased plasma volume and sweat rates, as well as reduced core temperature and ratings of perceived exertion. In a very small number of subjects, glycerol consumption has been associated with side-effects including nausea, gastrointestinal discomfort, dizziness, and headaches. In summary, while glycerol and fluid ingestion results in hyperhydration, the documented benefits to exercise performance remain inconsistent.
van Rosendal
Simon P
SP
The University of Queensland, School of Human Movement Studies, Brisbane, Queensland, Australia. svanrosendal@hms.uq.edu.au
Osborne
Mark A
MA
Fassett
Robert G
RG
Coombes
Jeff S
JS
D001833:Body Temperature Regulation / Q000187:drug effects / Q000502:physiology; D001834:Body Water / Q000378:metabolism / Q000502:physiology; D003681:Dehydration / Q000378:metabolism; D005990:Glycerol / Q000009:adverse effects / Q000494:pharmacology*; D006801:Humans; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology; D014882:Water-Electrolyte Balance / Q000187:drug effects / Q000502:physiology
D005990:Glycerol