Purpose: to study the features of the influence of training loads in bodybuilding with the sequential use of basic and isolation exercises on the nature of adaptive body changes in athletes. Methods. 60 bodybuilders aged 18 ± 0.23 were divided into 3 groups, which used different combinations of basic and isolation exercises at the stage of specialized basic training during 4 months. To determine the effectiveness of the proposed training programs on the nature of adaptive changes in the body of athletes we used morphometric parameters, indicators of bioimpedansometry and biochemical analysis of cortisol concentration and lactate dehydrogenase activity in the blood. Results. The pronounced adaptive changes for the period of research were observed mainly in athletes of the third group due to increase in the circumferential sizes by 7.7% (p <0.05) and increase in fat-free mass by 8.5% (p <0.05) and decrease in body fat by 9.1% (p <0.05). Representatives of groups 1 and 2 also had positive dynamics in circumferential sizes and body composition, but with a less pronounced progression over the same period. At the same time, the results of biochemical blood control indicated the manifestation of compensatory reactions in response to physical stimuli in bodybuilders of group 1, especially at the beginning of the study. Thus, group 1 athletes had a decrease in the cortisol concentration by 26.8% (p <0.05) on the background of a significant increase in LDH activity by 37.4% (p <0.05) in the blood almost to the upper limit of the norm. Athletes of groups 2 and 3 showed a safe increase in cortisol concentration and LDH activity in response to a stress stimulus. At the end of the study, we observed the effect of long-term adaptation mainly in group 3 athletes on the background of no significant changes in cortisol concentration and LDH activity in the blood serum in response to exercise, which indicated increasing the body resistance to the physical stimuli. Conclusion. Using the proposed mechanism of the training process correction at the stage of special basic training in bodybuilding allows to optimize the training load parameters as well as achieve pronounced adaptive changes in the body of athletes and their muscle growth.