The inverse linear relationship between respiritory muscle blood flow and extremity muscle deoxygenation shows that the work of breathing is increasing in proportion to extremity muscle work. Additionally, there is significant deoxygenation in the respirotry muscles (not displayed in this picture) and a significant reduction in extremity muscle blood volume (also not featured). The latter indicates a redistribution of cardiac output from the extremity muscles to the respiritory muscles (steal phenomenon / respiritory metaboreflex) and the former is a sign of respirotory muscle oxygen extraction supeceding oxygen supply. Collectively this suggest the prescence of a respiritory limitation (significant reductions in SpO2 corroborate this as well meaning that a pulmonary diffusion limitation may be present)