Background & Aims: The purpose of this study was to investigate the effects of resistance and endurance concurrent training combined with ingested of L-Carnitine supplementation on hormonal changes, lipid profile, and body composition in obese men.

Materials & Methods: Twenty four young obese men (age: 23.6±2.4 years and BMI: 32.4±1.6 kg/m²) volunteered to participate in this study and were randomly divided into two groups of 12 people taking the supplement and placebo. Both groups performed the same concurrent resistance and endurance training program (3 times a week for 8 weeks). The supplement group consumed daily 3g of L-carnitine and the placebo group ingested the same amount of maltodextrin. Blood samples were collected before and 36h after completion of the training course in the fasting state. The paired sample t-test was used to determine differences within a group, and differences between groups were analyzed using independent t-test.

Results: In both supplement and placebo groups a significant decrease were seen in body weight, fat mass, body fat percentage, cholesterol, TG and LDL-c after 8 weeks of concurrent training. Moreover, a significant increase was observed in HDL-c (p≤0.05). After more, a significant increase in cortisol (in both groups) and testosterone (only in the supplement group) were observed (p≤0.05). However, in all the variables mentioned, there were significant differences between groups in favor of the group receiving carnitine at the post-test. In other words, the rate of improvement was significantly greater in the supplement group compared to the placebo group (p≤0.05).

Conclusion: Although the implementation of a combination of resistance and endurance training for 8 weeks improves body composition, lipid profile and hormonal changes in obese subjects, but the rate of progress was significantly improved with supplementation of L-carnitine.