Sodium Bicarbonate: The Cheapest Legal Ergogenic in Sport

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Sodium bicarbonate — the same baking soda that's in most kitchens — is not the first supplement most athletes think of, but it's one of the most thoroughly studied. The Australian Institute of Sport rates it an "A" supplement (strong evidence in specific situations), and the International Society of Sports Nutrition issued a position stand in 2021 endorsing it for high-intensity exercise.

How it works

During hard anaerobic work, hydrogen ion (H+) accumulates inside muscle, dropping intracellular pH and slowing key glycolytic enzymes. Bicarbonate raises blood buffering capacity, which helps muscle dump H+ and lactate into the blood and keeps the muscle pH from falling as far. A meta-analysis in Sports Medicine covering 38 studies and 137 performance estimates found a mean 1.7% increase in performance with single doses of 0.3 g/kg body mass in short maximal efforts (Carr 2011; PMID 21923200; DOI 10.2165/11591440-000000000-00000). An umbrella review of meta-analyses on the topic concluded that the evidence for bicarbonate is moderate-quality for ergogenic effects on Wingate-style anaerobic power, Yo-Yo intermittent running performance, and 30-second to 8-minute high-intensity exercise (Grgic 2021; PMID 34794476; DOI 10.1186/s12970-021-00469-7).

Dose, timing, and protocol

The ISSN position stand recommends 0.2–0.5 g/kg body mass, with 0.3 g/kg as the optimal single dose; higher doses don't add benefit but do worsen side effects. Standard timing is 60–180 minutes before exercise, adjusted to the individual's GI response. Multi-day protocols, where 0.4–0.5 g/kg/day is split across three meals for 3–7 days before competition, can be effective and reduce same-day GI risk (Grgic 2021 ISSN; PMID 34503527; DOI 10.1186/s12970-021-00458-w).

Who benefits most

The biggest gains are seen in events that are hard, short, and limited by anaerobic glycolysis: 400–1,500 m running, 100–400 m swimming, 1–4 km cycling time trials, rowing 2,000 m, combat sports, and repeated sprints in team sports. Effects on muscle strength and pure repeated-sprint ability are less consistent, and there's little benefit for marathon-paced efforts — the bottleneck there isn't H+ accumulation.

The GI problem

The single biggest practical limitation is gut distress: belching, bloating, nausea, abdominal pain, and urgent diarrhoea, particularly with the 0.3 g/kg single dose. The position stand suggests using lower doses (0.2 g/kg), splitting across 30–60 minutes, taking it with a carbohydrate-rich meal, using enteric-coated or gelatin capsules, or switching to multi-day loading. Always test the protocol in training, never first on race day.

Stacking

The ISSN review concludes that combining bicarbonate with creatine or beta-alanine may produce additive effects. Beta-alanine raises intracellular carnosine (an intramuscular buffer); bicarbonate raises extracellular buffering, so the two operate at different sites. Whether bicarbonate combined with caffeine or nitrate adds extra benefit is still unclear.

Safety

For healthy athletes, single-dose acute use at ergogenic doses is well tolerated. The sodium load is non-trivial — a 0.3 g/kg dose in a 70 kg athlete delivers about 1,600 mg of sodium — so it's not appropriate for people with uncontrolled hypertension, heart failure, severe kidney disease, or low-sodium-restricted diets. Long-term daily megadoses can cause metabolic alkalosis and hypokalaemia.