Why is glycerin gaining attention as a sports supplement ingredient?

Why is glycerin gaining attention as a sports supplement ingredient?
Beyond cosmetics and industrial uses, glycerin is recognized internationally as a Class A sports supplement with solid evidence. It serves as a gluconeogenic substrate and a powerful water-binding agent—1 gram can hold about 3 grams of water. Studies show endurance athletes taking glycerin before training improved endurance by roughly 21% and reduced urine output by 670 ml while increasing body fluid by 730 grams. Another trial found cycling endurance improved by 24%. Historically, glycerin was used by militaries for long marches and was even on the IOC banned list until September 1997. Its dual role in hydration retention and energy metabolism makes it attractive for endurance sports, though it is not yet mainstream in China's supplement market.