If you run or cycle as hard as you can, you start to breathe hard, and suddenly your leg muscles start to burn because your muscles have become acidic. It’s the burning in your muscles that forces you to slow down. Muscles get the energy to move your body from the food that you eat. Carbohydrates are broken down step by step in a chain of reactions to release energy for your muscles. Each step requires oxygen. If you have enough oxygen, the carbohydrates are eventually broken down to carbon dioxide and water that you can blow off from your lungs. However, if you can’t get all the oxygen that you need, the series of reactions stops and lactic acid accumulates in your muscles and spills over into your bloodstream. The acidity in muscles caused by the accumulation of lactic acid is what makes your muscles burn.
When acid is exposed to an alkaline or base, it combines with it to neutralize the acid and form water. What would happen when an athlete takes the base, sodium bicarbonate, before he competes? He would be able to exercise longer if the bicarbonate got into the muscle and neutralized the burning caused by the acid. The authors of this study showed that higher doses of sodium bicarbonate were more effective in preventing burning. This exercise aid is still experimental, so we will have to wait for further research to see if it really works.