Hypotonic

Hypotonic solutions have a lower concentration of salts and sugars than body fluids, which means they deliver fluid more quickly than higher-concentration drinks.

Low‑Solute Solutions

A hypotonic solution contains fewer dissolved, non‑permeating particles than the fluid inside our cells. Because water moves from areas of low solute concentration to high, drinking a hypotonic beverage encourages water to cross the gut lining and enter the bloodstream rapidly. In terms of osmolality or tonicity, hypotonic drinks are below the range of human blood plasma (roughly under 275 mOsm/kg). They typically contain a modest amount of sodium and potassium to replace electrolytes lost in sweat, but they deliberately keep carbohydrate content low. This reduces the risk of gastrointestinal discomfort and promotes faster gastric emptying, which is essential during long, hot training sessions when sweat losses are high.

Rapid‑Rehydration Drinks

Examples of hypotonic sports beverages include plain water fortified with a pinch of salt, lightly sweetened electrolyte waters, diluted sports drink concentrates, and oral rehydration solutions formulated for illnesses. Some coconut waters and mineral waters also fall into this category because their natural sugar and mineral content is lower than that of typical sports drinks. Athletes often prepare their own hypotonic mix by combining a small amount of powder or concentrate with a larger volume of water to suit high‑heat or ultra‑endurance events.

Hypotonic drinks quench thirst quickly and keep the body hydrated without delivering large amounts of sugar. They are best used when rapid fluid replacement is the priority.

Related Terms: Isotonic, Hypertonic, Tonicity, Osmolality, Osmolarity