Oxygen, a stable di-radical, is critical for aerobic life, and a mismatch between its supply and demand during exercise decreases performance and precipitates fatigue. In this chapter, we highlight the critical redox components (i.e., signaling as well as structural and functional modifications mediated by reactive oxygen and nitrogen species) at each step of the oxygen pathway from atmospheric air to muscle mitochondria. We split the oxygen pathway into five major “stages”: (1) lungs, (2) erythrocytes, (3) microcirculation, (4) muscle and (5) mitochondria. We present evidence that redox mechanisms regulate oxygen transport throughout. Thus, oxygen transport can no longer be considered a redox neutral area. Following a quantitative approach, we emphasize the need to implement more spatiotemporally refined redox interventions to increase oxygen delivery and improve exercise performance. The architectural and numerical basis of oxygen transport can inform experimentally testable predictions in redox biology, exercise physiology and sports nutrition.