Background & Objective: Narcotics abuse can induce liver disorders; nevertheless, exercises improve liver disorders. The present research aimed to review the effect of eight weeks forced swimming training with methadone supplementation on liver enzymes of rats.

Material & Method: In this experimental research, 48 rats were selected, and after one week adaptation to lab environment, they were randomly divided into four groups of 12 rats including (1) forced swimming training, (2) methadone supplementation, (3) forced swimming training with methadone supplementation, and (4) control. Groups 2 and 3 used 2 mg/kg methadone daily for 8 weeks. Also, groups 1 and 3 swam for 8 weeks, three sessions per week and each session for 30 minutes. For statistical analysis of data, one way ANOVA and Tukey post hoc tests were used (α≤0.05).

Results: Findings showed that forced swimming training, methadone supplementation, and forced swimming training with methadone supplementation had no significant effect on AST (P=0.90) and ALT (P=0.99) enzymes; forced swimming training had significant effect on increase of ALP (P=0.001); also, forced swimming training, compared with methadone supplementation and combination of forced swimming training with methadone supplementation, had significant effect on increase of ALP (P=0.001).

Conclusion: Accordingly, 8 weeks of forced swimming training with methadone has possibly no significant effect on liver enzymes.