Respiratory limitations to exercise

This chapter introduces the concept of respiratory limitation and discusses the importance of understanding differences between demand and/or capacity issues. Traditionally, the respiratory system in healthy individuals has been described as ‘overbuilt’ for the demands placed on it during intense muscular exercise. It describes the normal adaptations that occur in response to athletic training. The chapter introduces the concept that airflow limitation may impact athletic performance. It explains how exercise-induced arterial hypoxaemia may occur and its impact on exercise performance. The chapter discusses how respiratory muscle function may contribute to respiratory limitation. Oxygen delivery to the active locomotor muscles is thus impaired, which enhances the perception of exertion and catalyses the onset of quadriceps muscle fatigue. Operating lung volumes during exercise leads to augmented respiratory neural drive and a high energetic work of breathing, which may be linked with earlier onset of respiratory muscle fatigue.