Respiration and heat in contracting and non-contracting dissipative muscle.

The oxygen consumption-heat relationship is analyzed using a scheme of reactions underlying muscle aerobic metabolism. The enzymatic chemical reactions of the scheme are considered near equilibrium during a contraction, and far from equilibrium during energy dissipation in a non-contracting state. Implications show that for two different metabolic rates, the proportionality between oxygen consumption and heat is a very specific case, because of restricting necessary conditions.