This is adapted from the book, Eat Smart, Play Hard, by RW USA Nutrition Editor Liz Applegate.
There may be something here if youre a sprinter. Taking a few spoonfuls of sodium bicarbonate (commonly known as baking soda) several hours before a brief but intense bout of exercise may improve your staying power. Thats because sodium bicarbonate acts as a buffer in the body, so it decreases lactic acid levels.
Heres how it works. During high-intensity (anaerobic) exercise such as sprinting, your body uses pure carbohydrate no fat as a fuel source. A by-product of anaerobic exercise is lactic acid, which is normally cleared away and subsequently used as an energy source itself. If your body produces lactic acid faster than it clears it, the acid begins to hamper muscle contractions, and you get that heavy feeling in your legs.
Several studies have shown that a dose of sodium bicarbonate can delay that feeling, improving performance during short bouts of exercise. But would a shot of sodium bicarbonate before a longer, yet still intense, session of exercise a 5-K run, for instance give you an edge?
Researchers from the University of Kansas in Lawrence tested this hypothesis on runners. Each was given 20 grams of sodium bicarbonate 2 hours before an intense 30-minute treadmill run. At the end of the run, the runners sprinted to exhaustion, simulating a finishing kick in a race. The runners gained no benefit from the supplementation, as they sprinted for the same length of time as did a placebo group. One thing this experiment did show is that something other than lactic acid buildup contributes to end-of-race fatigue.
My recommendation: Sodium bicarbonates fatigue-busting powers come into play only for short-duration, high-intensity exercise, such as sprinting. And beware: Large doses (20 grams or more) of sodium bicarbonate may cause severe intestinal cramping, bloating, and diarrhea, so use it sparingly and only for sprint-type exercise.