Conclusions
Using sets of machine exercises in combination with high intensity training load contribute to the growth of strength capabilities and muscle mass of bodybuilders at the stage of specialized basic training in the shortest possible time. The absence of additional involvement of stabilizer muscles in the process of performing machine exercises allows to reduce energy consumption in most cases, and using high intensity training load in the conditions of anaerobic-alactate energy supply mode will allow to increase the reserves of the creatine phosphokinase mechanism of ATP resynthesis and thus the efficiency of the long-term adaptation process as a whole. The implementation of the study results in the training activity will help to find effective ways of optimizing training load taking into account the adaptation potential of the body, the peculiarities of the training stages and muscle activity.The studied blood biochemical markers were used for evaluating adaptive changes in bodybuilders in response to high and medium intensity training load while using machine and free weight exercises. A clear distinction of changes in LDH activity and creatinine concentration in the blood serum in response to this stress stimulus allows to determine the level of involvement of certain energy supply modes and energy recovery mechanisms during muscle activity, which in the perspective will help with developing innovative systems for load correction and optimization of the training process as a whole.