Osmolality

Osmolality measures how concentrated the dissolved particles in a drink are, which influences how quickly fluid leaves the stomach and is absorbed. "Hypotonic" mixes — less concentrated than body fluids — market on faster absorption during exercise, while sugary sports drinks sit higher. It is a real physiology concept, and also a marketing hook, so we report it as a factual property when a brand discloses it and keep the absorption claims framed as general information rather than a performance promise.