This work describes the interaction in the conditions of the aerobic and anaerobic energy mechanisms for short-term endurance sports, in particular in the athletic discipline of 400m. The examinations were carried out on treadmill, during training and after 400m competitions. In the combination of the lactate thresholds, the results of treadmill tests were used as base for evaluation. Ascertained was the speed V with a lactate concentration of 4mmol/l (VL4) and constant „b“, following the rising of the lactate result. The examinations showed that during 400m competitions, 55% of the energy performance came from the aerobic energy mechanism. The relation between height (VL4) and constant „b“ from the lactate results can therefore be identified and explain the energetic process flow during muscular activities. The anaerobic energy supply is distinct between performance (mobilisation) and capacity (accumulation). The definition of energetic processes and cellular performances during the training in short-term endurance sports, as well as after 400m competitions, can be established in the term of short and intermediate training controls with the biochemical parameters of lactate and creatine kinase (CK).