Lactate after exercise in Man: II. Mathematical model.

A mathematical model of lactate kinetics after exercise has been constructed from the application of the mass conservation law and the following assumptions: 1. The total lactate distribution space is composed of two compartments, i.e., (M) the previously working muscles and (S) the remaining lactate space; 2. The rates of lactate release and utilization in (M) and (S) are proportional to the lactate contents of these compartments; 3. The post-exercise lactate production rates in (M) and (S) are constants; 4. Arterial lactate concentration can represent the average lactate concentration in (S). Consideration of experimental facts reported in the literature shows these assumptions to be reasonable. The relationships obtained express the compatibility of parameters and time functions concerning lactate concentrations, as well as rates of production, uptake, release, and utilization. They open the way to various applications, especially those involving numerical fits to observed time courses of lactate concentrations.