The Muscle Mag
The research, recently published in the Journal of the International Society of Sports Nutrition, yielded no significant impact of pre-exercise glycerol on various variables such as dehydration, metabolism, kinematics, and thermography, including blood lactate levels, relative oxygen uptake, and heart rate in international race walkers. Even in the case of body mass loss post-exercise, which is a measure of dehydration, glycerol was found to be outperformed by a water placebo.
Francisco Javier Martínez-Noguera of the Catholic University of Murcia, Spain, along with colleagues, noted the need to find solutions for athletes competing in high-temperature and high-humidity conditions, especially considering global warming trends and the timing of major competitions in August, the hottest month of the year.
Lack of Effect
The study involved eight experienced race walkers with specific criteria for participation, including a mean age of 28 years, mean body mass of 65.6 kg, and mean height of 180 cm. The athletes underwent medical evaluations and then consumed glycerol or a flavored water placebo in a crossover design. The results of the study did not show significant improvements in dehydration factors or exercise performance.
Although there was a notable difference in body mass loss between the glycerol and placebo groups during the exercise test, other dehydration factors showed no substantial variations. Additionally, there was no significant impact of glycerol on perceived exertion or other exercise performance metrics.
It was suggested that the chosen temperature and humidity levels during the test may not have been extreme enough to elicit significant differences in the evaluated variables.
‘Equivocal’ Evidence
Susan Kleiner, Chief Science Officer at Electrolyte Boost, commented on the study, noting that historical research on glycerol has yielded mixed results. The findings of this study may support the argument that glycerol is not effective in combating dehydration and enhancing performance in warm climates.
Similarly, Chris Mohr, Fitness and Nutrition Advisor at Fortune Recommends Health, cautioned against the overhyping of glycerol for exercise performance and emphasized the importance of hydration and acclimatization for athletes in high-temperature conditions.
Source: Journal of the International Society of Sports Nutrition 2024, 21(1)
doi: 10.1080/15502783.2024.2346563
“Effects of Pre-exercise Glycerol Supplementation on Dehydration, Metabolic, Kinematic, and Thermographic Variables in International Race Walkers”
Authors: Francisco Javier Martínez-Noguera et al.
