Abstract des Autors

The dynamic change of the phophorylation state of the high energy phosphate system as well as the activity of oxydative phosphorylation and glycolysis as function of mechanical power and time including lactate distribution and elimination can be calculated by numerically solving a set of differential equations in a computer program. The model exhibits two different stages of the metabolic behaviour, the stage of a metabolic steady state and the non-steady state. 1. The metabolic steady state is maintained by the equilibrium of the ATP dephosphorylating and rephosphorylating reactions, including the establishment of a lactate steady state at a low level of concentration below a certain range of power, known as anaerobic threshold (AT). 2. The state of the non-steady state is obtained, when a net lactate production leads to a continous lactate accumulation during dynamic exercise, at a level of power, which exceeds the power relating to AT. Lactate distribution is calculated in a two compartment model, where the volume of the lactate space (i.e. active and passive space) is estimated to about 35% to 45% of body mass. Active muscle mass in running is about 27% to 35% of body mass. By variation of active mass, the maximal rate of oxidative phosphorylation (VO2max) and glycolysis (VLamax) fitted with the real measured values an athlete can obtain. This allows a more precise evaluation of the individual aerobic and anaerobic metabolic capacity. Verf.-Referat