Lactic acid buildup is a result of low levels of oxygen in your blood, and when there is a low concentration oxidative phosphorylation cannot occur. Without oxidative phosphorylation, the product of glycolysis (pyruvate) does not go through the krebs cycle, but goes through lactic acid fermentation, which creates lactic acid, ATP, and substrates for glycolysis to continue. So stop feeding yourself baking soda and breath while you're riding your bike..