Sodium bicarbonate

Sodium bicarbonate is a salt composed of sodium ions and bicarbonate ions, widely known as baking soda. In sports hydration it acts as an alkaline buffer and provides sodium to replace losses.

Physiological effects and hydration role

Sodium bicarbonate dissociates into sodium (Na⁺) and bicarbonate (HCO₃⁻) when dissolved. The sodium is one of the body’s principal extracellular cations and helps maintain fluid balance and nerve function, while the bicarbonate acts as a base that neutralises hydrogen ions and maintains blood pH. Oral sodium bicarbonate is commonly used to relieve heartburn and treat metabolic acidosis. In intravenous form it dissociates completely and raises serum bicarbonate, which buffers excess hydrogen ions. One gram of sodium bicarbonate supplies around 11.9 milliequivalents of sodium, making supplementation a significant sodium load. Large doses can create a hyperosmolar state and lead to fluid retention and tissue oedema. In sports, high-intensity exercise generates acids that contribute to fatigue. Supplementation with 0.3 g/kg sodium bicarbonate can temporarily raise blood bicarbonate levels, buffer acids and expand plasma volume, but benefits vary between individuals. Rapid administration or excessive intake may increase intravascular fluid volume and risk of alkalosis.

Uses and practical notes

Sodium bicarbonate is best known as the leavening agent in baking and as an over‑the‑counter antacid. Food manufacturers add it to effervescent drinks and some processed foods to control acidity. In sports nutrition, it is not a standard ingredient in electrolyte drinks because it imparts a strong alkaline taste and delivers a very high sodium load. Athletes sometimes take sodium bicarbonate capsules to buffer lactic acid during short, high‑intensity events, but this practice can cause bloating, nausea and diarrhea if the dose is too high. The fluid‑retention effect of sodium bicarbonate has prompted research into its use as a hyperhydrating agent, yet any plasma volume expansion is accompanied by a rise in sodium load and potential gastrointestinal discomfort. People with hypertension, heart or kidney conditions should avoid large doses. Most athletes can meet their sodium needs through balanced diets and standard sports drinks without resorting to baking soda.

Sodium bicarbonate is an accessible compound that neutralises acids and supplies sodium, but its benefits for hydration are limited and its side effects significant. When used judiciously under professional guidance it may aid short‑term performance, but it is not necessary for routine hydration strategies.

Related Terms: sodium citrate, sodium chloride, potassium citrate, magnesium citrate, hydration