What effect does pre-exercise ingestion of glycerol have on the body?

Pre-exercise ingestion of glycerol has been shown to be beneficial for hydrating the body, which is primarily reflected in the increase of plasma volume. When glycerol is consumed prior to exercise, it can help draw water into the bloodstream, leading to an expansion of blood volume. This expansion can enhance circulatory efficiency, improve thermoregulation, and support sustained endurance performance by decreasing the risk of dehydration during prolonged physical activities.

The increased plasma volume helps maintain blood pressure and improves cardiac output, which are essential for optimal performance, especially during endurance events. Enhanced plasma volume can also aid in delivering nutrients and oxygen to working muscles while assisting in the removal of metabolic waste products, thus potentially improving overall exercise performance and endurance.

Additionally, while glycerol has some effects on fat oxidation and may have negligible effects on muscle glycogen stores, its primary role in the context of pre-exercise supplementation revolves around the increase in plasma volume, making it a vital factor for athletes, particularly those participating in endurance sports.