en Physical medicine Physical medicine پژوهشي Research <div style="text-align: justify;"><span style="font-size:9pt"><span minion="" pro="" style="font-family:"><b>Introduction</b>: Angiogenesis, the formation of new capillaries from pre-existing vessels, crucially involves activation of the hypoxia-inducible factor 1 (<i>HIF-1</i>) and vascular endothelial growth factor (<i>VEGF</i>) genes. This study investigates the impact of exercise intensity on the expression of angiogenic genes in the hearts of male rats.</span></span><br> <span style="font-size:9pt"><span minion="" pro="" style="font-family:"><b>Materials & Methods</b>: Eighteen male Wistar rats were randomly assigned to three groups: High-Intensity Interval Training (HIIT), Continuous Training (CT), and control (C). Both HIIT and CT groups underwent 8 weeks of training with five sessions per week. Anesthesia and blood sampling occurred 48 hours post final training session. Gene levels of <i>HIF-1</i> and <i>VEGF</i> were measured in the left ventricle. Data analysis employed ANOVA and LSD post hoc tests (P&le;0.05).</span></span><br> <span style="font-size:9pt"><span minion="" pro="" style="font-family:"><b>Results</b>: <i>VEGF</i> gene expression significantly increased in both HIIT and CT groups compared to the control group (P = 0.001), with a more pronounced elevation in the HIIT group than the CT group (P = 0.004). Furthermore, <i>HIF-1</i> levels exhibited a significant reduction in both HIIT (P = 0.001) and CT (P = 0.001) groups compared to the control group, with the HIIT-induced decrease surpassing that of the CT group (P = 0.049).</span></span><br> <span style="font-size:9pt"><span minion="" pro="" style="font-family:"><b>Conclusion</b><b><span style="font-size:11.0pt"><span new="" roman="" style="font-family:" times="">: </span></span></b>The noteworthy elevation in <i>VEGF</i> and decrease in <i>HIF-1</i> gene expression levels in trained rats imply that exercise training enhances angiogenesis. Importantly, the extent of this enhancement is contingent upon exercise intensity, with HIIT demonstrating more pronounced positive effects on <i>VEGF</i> levels.<span lang="FA" dir="RTL" style="font-family:"Times New Roman",serif"></span></span></span></div> Exercise Intensity, Continuous Training, High-Intensity Interval Training, Heart Tissue 43 53 http://jbrms.medilam.ac.ir/browse.php?a_code=A-10-483-1&slc_lang=en&sid=1 Shokoufeh Kheradmand shokofe_bahar1990@yahoo.com 10031947532846006442 10031947532846006442 No Faculty of Sport Sciences, University of Mazandaran, Babolsar, Iran Mohammad Reza Asad m_r_asad@yahoo.com 10031947532846006443 10031947532846006443 No Department of Physical Education and Sport Sciences, Payame Noor University of Karaj, Alborz, Iran , Reza Mir Javadi reza_schon@yahoo.com 10031947532846006444 10031947532846006444 No Department of Sport Physiology, Karaj Branch, Islamic Azad University, Karaj, Iran Narges Kheradmand pnu.kheradmand@gmail.com 10031947532846006445 10031947532846006445 No Department of Physical Education and Sport Sciences, Payame Noor University, Garmsar, Iran Mohamad Fashi m_fashi@sbu.ac.ir 10031947532846006446 10031947532846006446 Yes Department of Exercise Physiology, Faculty of Physical Education and Health Sciences, Shahid- Beheshti University, Tehran, Iran