Performance: 0.2–0.3 g/kg about 60–90 min beforehand, split to avoid digestive upset. Acidosis/CKD: 0.3–0.5 mEq/kg/day orally, adjusted by nephrology to keep serum bicarbonate between 22 and 26 mmol/L. Do NOT self-medicate.
Corrects low serum bicarbonate in moderate-to-advanced CKD and slows the decline in glomerular filtration rate in controlled trials.
View the study (clinical trials) →In CKD with acidosis, it delays progression to dialysis and improves nutritional status.
View the study (clinical trials) →⏱ 3 min read
Sodium bicarbonate (NaHCO₃) is an alkaline salt widely used in the home, in cooking, in pharmacy, and in sports; it has the chemical property of , a characteristic that is the basis of practically all of its clinical applications: digestive antacid, neutralizer of severe metabolic acidosis, urinary alkalinizer in some specific kidney conditions, and, in sports, an ergogenic aid with solid scientific support for lactic anaerobic efforts of short to medium duration.
Unlike many ergogenic supplements with heterogeneous data, sodium bicarbonate is in specific disciplines, recognized by the International Olympic Committee and the International Society of Sports Nutrition as a proven ergogenic aid for high-intensity lactic anaerobic efforts lasting between 1 and 7 minutes, alongside creatine, caffeine, beta-alanine, and nitrates.
The indication with the strongest clinical support is performance in (typically disciplines such as 2,000 m rowing, 200-400 m swimming, track cycling, middle-distance running, repeated sprints in team sports, combat sports); several meta-analyses have documented in performance with acute supplementation at doses of 0.3 g/kg of body weight taken 60-180 minutes before the effort.
The mechanism of action is clear: bicarbonate generated during lactic anaerobic metabolism, delaying the drop in muscle pH and making it possible to maintain power and strength during repeated high-intensity efforts; this effect is complementary to that of beta-alanine (which acts at the intracellular level via carnosine), and the combination of both supplements appears to provide additive benefits in some disciplines.
In uric acid kidney stones (and in refractory gout with high uric acid levels), urinary alkalinization with oral sodium bicarbonate , an established clinical indication supported by nephrology guidelines; the doses used are specific and require medical supervision to keep urinary pH in the therapeutic range without producing systemic alkalosis.
In metabolic acidosis associated with advanced chronic kidney disease, oral sodium bicarbonate at adjusted doses and reduces some complications (sarcopenia, bone, metabolic complications); it is a recognized clinical indication and one that is frequently used in nephrology.
As a household digestive antacid, sodium bicarbonate produces through direct neutralization of gastric hydrochloric acid; the effects are immediate but brief, and frequent or prolonged use is not recommended because of the associated sodium load and the rebound effect (rapid neutralization of gastric acid stimulates compensatory secretions afterward); modern antacids (calcium, magnesium, and aluminum salts) and proton pump inhibitors have more favorable pharmacological profiles for sustained use.
For athletic performance, the dose studied is , spread over several small doses with plenty of water; commercial products in capsules or chewable tablets with an enteric coating are significantly better tolerated gastrointestinally than powder dissolved in water; alternatively, lower doses (0.1-0.2 g/kg) over several days before the event may produce similar benefits with better gastrointestinal tolerance.
The most important safety consideration in ergogenic use is gastrointestinal tolerance: high acute doses frequently produce in a significant proportion of people, which limits practical usefulness and makes individual trials necessary to find the optimal dose and formulation; people with high blood pressure, heart failure, kidney failure, or any condition that requires sodium restriction should avoid ergogenic use (doses of 20-25 g provide 5-7 g of sodium, equal to or greater than the total recommended daily intake); those who take lithium, quinolone antibiotics, tetracyclines, thyroid hormones, ketoconazole, or iron salts should separate doses because bicarbonate can alter their absorption; in pregnancy and breastfeeding, ergogenic doses should be avoided, although dietary doses and small antacid doses are perfectly safe; excessive doses can produce metabolic alkalosis with cramps, paresthesias, and tetany.
Information, not medical advice. Scientific evidence reflects the quality of the studies.