The effect of increasing work rate amplitudes from a common metabolic baseline on the kinetic response of Vo2p, blood flow, and muscle deoxygenation

A step increase in work rate produces a monoexponential increase in V̇o 2p and blood flow to a new steady-state. We found that step transitions from a common metabolic baseline to increasing work rate amplitudes produced a slowing of V̇o 2p kinetics, no change in blood flow kinetics, and a speeding of muscle deoxygenation kinetics. As work rate amplitude increased, the ratio of blood flow to V̇o 2p became smaller, while the amplitude of muscle deoxygenation became greater. The gain in vascular conductance became smaller, while kinetics tended to become slower at higher work rate amplitudes.