Muscle fatigue and muscle damage in strength training

Background and Study Aim The aim of this study is to investigate the effects of different types of contractions on muscle damage and muscle fatigue in sedentary individuals. Material and Methods Thirty healthy male sedentary individuals participated in the study. Strength training in different types of contractions applied in the study was applied 3 times a week for 8 weeks. Before the study, the training loads were determined by making maximal force measurements of all subjects. The 30 subjects participating in the study were divided into 3 groups: isometric (n = 10), concentric (n = 10) and eccentric (n = 10) contraction group. Appropriate amount of blood samples was taken from the elbow vein 2 times from all subjects, before the studies and at the end of the 8-week strength training. Results It was observed that eight-week strength training did not cause muscle fatigue in all groups and did not create a statistically significant difference (P> 0.05). Strength training with isometric and concentric contractions for eight weeks significantly increased serum lactate dehydrogenase (LDH), C-reactive protein (CRP), myoglobin (Mb), interleukin 6 (IL-6) levels, while concentric strength training significantly reduced serum aspartate amino transferase (AST) levels. Strength training with eccentric contractions significantly increased serum LDH, CRP, AST, Mb and IL-6 levels, while significantly reducing serum tumor necrosis factor alpha (TNF-alpha) levels. Strength training with eccentric contractions significantly increased serum creatine kinase (CK), CRP, AST, IL-6 and Mb levels compared to strength training with isometric and concentric contractions at the end of the eight-week study period, but did not show the same significant effect in other parameters. Conclusions As a result, it can be said that eccentric strength training performed in sedentary individuals leads to more muscle damage than isometric and concentric strength training.