Participants
±
A total of 64 athletes aged 18–20 years were examined. Their experience of training in bodybuilding is 4.2 ± 0.4 years. A series of studies was conducted over 12 weeks in 2021 on the basis of fitness centers Gold Gym, Fight House, Septem Fitness, and Gym Style (Ukraine). The research participants were randomly divided into four groups, 16 athletes in each group. Athletes of groups 1 and 3 used a complex training regime which included free weight exercises. Participants of groups 2 and 4 used machine exercises for all training. However, bodybuilders of groups 1 and 2 trained in conditions of medium intensity training load (The algorithm, structure and methods of the study were approved by the ethical committee for biomedical research of Lesya Ukrainka Volyn National University (ecbr18.08.2022) in accordance with the ethical standards of the Declaration of Helsinki. Participants gave written informed consent for the research in accordance with the recommendations of the biomedical research ethics committees (Diagnostic equipment of the university medical and biological laboratory was used for conducting medical examination, assessment of functional status, indicators of body composition and biochemical control of creatinine concentration and LDH activity in the blood serum of the participants of the examined groups.