Introduction: Sports activity increases the expression of PGC-1α, the regulatory factor of mitochondrial biogenesis. This study aimed to investigate the effect of eight weeks of Moderate-intensity Continuous Training (MICT) and High-intensity Intermittent Training (HIIT), along with sodium citrate supplementation, on PGC-1α expression in male Wistar rats. Method: Forty rats were placed in the following five groups: Control, MICT, MICT+sodium citrate, HIIT, and HIIT+sodium citrate. The continuous training group ran for eight weeks and five sessions per week with an average intensity of 70% of the maximum running speed for 15-30 minutes. The interval training group ran for 12 minutes with an intensity range of 50% and 90%. In addition to exercise, the exercise+supplement groups received 15 mmol/l sodium citrate supplement daily. The expression of PGC-1α in the soleus muscle was measured by the western blot method. Data analysis was done using one-way analysis of variance and Tukey's post hoc test. Results: The PGC-1α protein expression increased in both the training groups and the training+supplement groups compared to the control group (P=0.001). Furthermore, adding sodium citrate could significantly increase the PGC-1α expression in the MICTgroup+supplement compared to the MICT group (P=0.005). However, the HIIT had a higher effect on PGC-1α expression than the MICT group. Conclusion: Despite the effectiveness of both training methods, sodium citrate supplementation before HIIT could have more synergistic effects in increasing the expression of PGC-1α.