GLOSSARY

Chloride Ion (Cl⁻) is the electrically charged form acting as an ion in body fluids, distinct from the free element.

Distinguish the cellular role of chloride from supplement outcomes; a transporter or enzyme does not prove extra intake improves sport.

Chloride is the main extracellular anion, contributing to charge, fluid and acid-base balance and forming part of gastric acid. Although often consumed with sodium, blood chloride and sodium do not measure exactly the same phenomenon. Gastric acid's importance is not a reason to add chloride or acid for every athlete's digestion. Normal function differs from untargeted extra supplementation.

Sodium is mainly the extracellular cation and potassium mainly intracellular; chloride and other anions contribute to charge balance. Selective membranes, transporters and energy expenditure maintain these distributions. Blood concentration does not directly report muscle content. Movement between compartments may occur faster than changes in total stores and can affect a sample even without a corresponding dietary change.

Ions move under both concentration and electrical forces; the electrochemical gradient combines these components. Membrane potential describes voltage across a membrane, not the muscle's food energy. Selective permeability and ion distribution both matter. This helps explain muscle excitation, but the existence of a gradient does not establish that an electrolyte supplement accelerates nerve signaling in an athlete already adequately supplied.