ABSTRACT
Metabolic acidosis represents an area of confusion with regard to exercise fatigue. This chapter discusses acidosis from the perspective of lactic acid, lactate, and hydrogen production. It describes the links between these factors and fatigue, and discusses recent research that challenges these links. Based on current research evidence, it appears that metabolic acidosis stemming from H+ production has a much smaller influence on fatigue during exercise than previously thought. In fact, there is evidence that a reduced pH can actually increase muscle force production and help to maintain muscle excitability. However, the small direct influence of H+ on muscle performance may still be sufficient to contribute to performance impairment during whole body exercise, particularly at the elite performance level. Furthermore, H+ production may impact performance in ways other than direct muscle impairment, such as by reducing central nervous system drive and increasing effort perception.
