Glycerol
Glycerol, most commonly provided in the form of glycerol monostearate has been a popular athletic performance enhancer for quite a long time. Over the past few years, newer and more concentrated forms of glycerol have hit the market, sparking resurgence into its popularity.
While many bodybuilders swear by the pump enhancing benefits of this ingredient, there is little clinical science to back up these claims. There is however, solid evidence showing the benefits of glycerol for improving hydration in athletes, although not at a dosage many average gym goers might expect.
What it does
Glycerol has been shown to “hyperhydrate” the body, or allow it to hold more water than it would be normally capable of. This can be a great benefit to endurance athletes who have the potential for dehydration during their training or competing.
By increasing the amount of water held in the body, an athlete would be able to train longer without the threat of dehydration, and therefore not succumb to the performance lowering threats associated with dehydration.
How it works
The mechanism of action for glycerol increasing water retention is not well understood. A leading theory is that it increases plasma osmolality which can decrease the antidiuretic hormone concentrations typically found in the body when excess fluids are consumed. Simply put, glycerol may help us hyperhydrate by lowering the concentration of hormones which tells our body to eliminate water when we take in more than normal[1].
Dosing
While most dietary supplements offer 1-3g per serving of a 10%-65% glycerol substance, the science shows us that this is woefully inadequate to provide hyperhydration of athletic performance enhancement. A major study performed on athletes used dosed of .5g/kg, 1g/kg, and 1.5g/kg(45g, 90g, 136g for a 200lbs athlete) and saw hyperhydration. Similar doses have been provided and tested for athletic performance, and the same style of results have been seen[1].
In short, glycerol can be beneficial for the athlete, however doses must be consumed at much higher amounts than traditionally provided by the dietary supplement industry.