Sodium bicarbonate, commonly known as baking soda, is used by athletes to enhance performance. High-intensity exercise often leads to a decline in muscular function, which limits the ability to sustain effort over time. Supplementing with sodium bicarbonate is a strategy intended to counteract this performance decline.
How Sodium Bicarbonate Buffers Exercise-Induced Acidosis
Intense physical activity relies heavily on the anaerobic energy system, which results in a rapid metabolic process inside the muscle cells. This process generates a high concentration of hydrogen ions (H+), causing the muscle cell environment to become more acidic. The resulting drop in pH, known as metabolic acidosis, contributes to muscular fatigue and the inability to maintain high power output.
The physiological issue is the accumulation of hydrogen ions. Lactate, which is produced alongside H+ ions, is actually a fuel source and a temporary buffer. Sodium bicarbonate works by increasing the concentration of bicarbonate ions (HCO3-) in the bloodstream, which serves as an extracellular buffer.
These circulating bicarbonate ions neutralize the H+ ions that move out of the muscle cells and into the blood. By increasing the blood’s capacity to neutralize these acidic compounds, the supplement helps to maintain a more favorable pH balance. This extracellular buffering action facilitates the continued efflux of H+ from the working muscle, delaying the onset of fatigue and allowing the athlete to sustain high-intensity effort for a longer duration.
Determining the Effective Performance Dose
Scientific consensus points to an optimal acute dose of 0.3 grams per kilogram of body weight (0.3 g/kg BW) taken before exercise. This dose is consistently shown to be the most effective in raising the blood’s bicarbonate levels to enhance buffering capacity.
Dosing below this amount, such as 0.2 g/kg BW, may still elicit a performance improvement, particularly for individuals sensitive to the supplement. Consuming higher doses, such as 0.4 g/kg or 0.5 g/kg BW, does not provide additional performance advantages. Instead, these higher quantities significantly increase the risk and severity of gastrointestinal side effects.
To calculate the required dose, an athlete must multiply their body weight in kilograms by 0.3. For example, a 70-kilogram athlete would require 21 grams of sodium bicarbonate (70 kg x 0.3 g/kg). For athletes who find acute dosing challenging, a chronic loading protocol can be used, involving 0.4 to 0.5 g/kg BW split into multiple smaller doses consumed daily for three to seven days leading up to an event. This strategy aims to elevate baseline bicarbonate levels more gradually, which may improve tolerance.
Timing Protocols and Managing Gastrointestinal Distress
The timing of sodium bicarbonate ingestion is important for maximizing its effectiveness and minimizing discomfort. For a single, acute dose, the supplement should be consumed between 60 and 180 minutes before exercise. This window allows the bicarbonate to be absorbed from the gut and reach peak concentration in the bloodstream, ensuring maximum extracellular buffering capacity is available during the high-intensity effort.
Gastrointestinal (GI) distress is the most common limiting factor for athletes using this supplement, such as nausea, bloating, abdominal cramping, or diarrhea. These symptoms occur when sodium bicarbonate reacts with stomach acid, producing a large volume of carbon dioxide gas. To reduce adverse effects, athletes can divide the total dose into two or three smaller portions, consuming them every 15 to 30 minutes within the pre-exercise window.
Athletes can also consume the dose with a large volume of fluid (0.5 to 1.0 liter of water) and alongside a low-fat, moderate-carbohydrate meal. The meal helps slow gastric emptying, while the fluid helps dilute the concentration of the solution. Some athletes find relief by using commercially available enteric-coated capsules, which are designed to bypass the stomach and dissolve later in the small intestine.
Athletes should test their preferred protocol during training sessions before any competition to assess individual tolerance and efficacy. Individuals with pre-existing conditions, particularly those related to hypertension or kidney function, should consult a healthcare professional before beginning sodium bicarbonate supplementation due to the supplement’s high sodium content.