Background: One of the important adaptations that occurs after exercise is increased capillary density or angiogenesis. Vascular endothelial growth factor, has a mitogenic role for endothelial cells and acts as an important intermediator in the process of angiogenesis. The aim of this study was to compare the effects of two kind of endurance training on vascular endothelial growth factor gene expression in healthy male rats.

Materials and Methods: In this laboratory experimental study, 18 male Wistar rats at the age of eight weeks, with an average weight of 210/5± 9/77g were  selected and randomely divided into three groups (control (n=6), ET (n=6) and HIIT (n=6)). Aerobic continuous training was performed 5 days a week, totally in eight weeks for 30 minutes with 70-75% VO2max and high intensity interval training consisted of three periods (four minutes with 90 to100% VO2max and two minutes with 50 to 60% VO2max). Vascular endothelial growth factor gene expression was measured by real time-PCR technique. To determine the significance of variables between these groups, one-way ANOVA and Tukey's post hoc tests were used.

Results: The results showed that the gene expression levels of vascular endothelial growth factor were increased significantly (p=0/006, F=7/243) in intense aerobic continuous and interval training groups compared to control group. Changes in exercise groups compared with each other were not significant.

Conclusion: According to the results of this study, increased levels of vascular endothelial growth factor gene expression in both training groups caused pro-angiogenic function in endothelial cells and an increase in ratsVO2max following eight weeks training may be due to increased angiogenesis process. High intensity interval training may cause faster adaptations in the body of organism than aerobic continuous training.