Sodium is one of the body’s electrolytes — minerals that can carry an electric charge when dissolved in fluids, such as your blood. Electrolytes are involved in many processes in the body, including regulating body fluids. When someone loses a substantial amount of fluid (sweating), which can be caused by prolonged strenuous exercise or when doing prolonged physical work in the heat, they will also lose more electrolytes — mainly sodium. To make up for the loss of sodium, some people — for example, some endurance athletes — may need to consume more sodium than the guidelines suggest.