Investigating sodium bicarbonate for better endurance performance

The ability of skeletal muscle to keep functioning during high-intensity endurance exercise is dependent, in part, on the body’s ability to limit decreases in pH. This phenomenon, also called exercise-induced acidosis, occurs both inside and outside of cells and is believed to be one of the major causes^[1] of muscle fatigue during exercise.

The onset of muscle fatigue is, in part, determined by the ability of the body to buffer decreases in pH. This means alkalizing agents like sodium bicarbonate (BICA) are attractive as potential performance enhancers (on paper, at least) since BICA can potentially buffer acid production and keep pH levels stable, as shown in Figure 1. Since BICA is the main buffer in the body for controlling pH outside of cells, supplementation to increase its levels (and therefore buffering capacity in the blood) can potentially delay muscle fatigue during exercise—if sufficient bicarbonate levels are achieved in the bloodstream.

Because high-intensity, short-duration exercise tends to produce the most lactate, most studies evaluating the effects of BICA on exercise performance involve this mode of exercise. Moreover, most studies use cycling as the type of exercise, which may not be applicable to other sports, such as endurance running. The study under review sought to evaluate the ergogenic effects of BICA supplementation on high-intensity endurance performance in runners.

Muscle fatigue during high-intensity exercise is caused in part by decreased pH in the blood and working muscles. Supplementation with sodium bicarbonate (BICA), a natural buffer, has shown some promise to help the body resist decreases in pH during high-intensity exercise of short duration. The present study examined the effects of BICA on longer-duration, high-intensity running.