en پزشکي فيزيکي و توانبخشي Physical Medicine and Rehabilitation پژوهشي Research <div style="text-align: justify;"><strong>Background</strong>: Dyslipidemia, marked by abnormal levels of total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides (TG), is a key risk factor for cardiovascular diseases. Radiotherapy (RT), while effective in cancer treatment, may induce adverse metabolic effects, including dyslipidemia. High-intensity interval training (HIIT) has shown potential in improving lipid metabolism. This study investigated the effects of HIIT on lipid profiles and body weight in rats undergoing RT.&nbsp;<br> <strong>Materials and Methods</strong>: This study was an experimental, randomized controlled trial conducted over 10 weeks. Twenty-four male Wistar rats (aged 8 weeks) were randomly divided into four groups (n=6 per group): Control, HIIT, RT, and HIIT + RT. The HIIT protocol consisted of 6 sessions per week on a treadmill, including familiarization (week 1), progressive overload (weeks 2&ndash;4), and stabilization phases (weeks 5&ndash;10). RT was administered as a single 11 Gy dose using a linear accelerator. Blood samples were collected post-intervention, and lipid profiles (TG, TC, LDL, and HDL) were analyzed using enzymatic assays and a spectrophotometer. Data were analyzed by SPSS software,version 26 using one-way ANOVA and Bonferroni post-hoc test; significance was set at P<0.05.&nbsp;<br> <strong>Results</strong>: Compared to controls, RT significantly increased TC (69.3&plusmn;3.1 mg/dL vs 59.5&plusmn;6.3 mg/dL, P=0.002), LDL (14.3&plusmn;1.2 mg/dL vs 11.5&plusmn;1 mg/dL, P=0.001), and TG (83.7&plusmn;3.5 mg/dL vs 75.7&plusmn;6.3 mg/dL, P=0.13) while decreasing HDL (21.7&plusmn;1.4 mg/dL vs 30&plusmn;3.3 mg/dL, P=0.001). HIIT significantly improved all parameters compared to RT alone: TC (52.0&plusmn;2.8 mg/dL vs 69.3&plusmn;3.1 mg/dL, P<0.001), LDL (9.5&plusmn;1 mg/dL vs 14.3&plusmn;1.2 mg/dL, P<0.001), TG (50.7&plusmn;6.3 mg/dL vs 83.7&plusmn;3.5 mg/dL, P<0.001), and HDL (36&plusmn;3 mg/dL vs 21.7&plusmn;1.4 mg/dL, P<0.001). No significant weight changes occurred (270.4&plusmn;28.7 g vs 274&plusmn;18.7 g, P=0.65). HIIT may counteract RT-induced dyslipidemia.<br> <strong>Conclusion</strong>: These findings suggest that HIIT may counteract RT-induced dyslipidemia, highlighting its potential as a therapeutic intervention. Further studies are needed to validate these results and explore underlying mechanisms.</div> Dyslipidemia, High-intensity interval training (HIIT), Radiotherapy (RT), Lipid profile 67 74 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-1352-2&slc_lang=en&sid=1 Mohammad Parastesh M-parastesh@araku.ac.ir 100319475328460012976 100319475328460012976 No Department of Sports Physiology, Faculty of Sports Sciences, Arak University, Arak, Iran. Behzad Aria b.aria@yazd.ac.ir 100319475328460012977 100319475328460012977 Yes Department of Sport Sciences, Faculty of Psychology and Educational Sciences, Yazd University, Yazd, Iran. Zahra Torkashvand z.torkashvand10@gmail.com 100319475328460012978 100319475328460012978 No Student Research Committee, School of Paramedicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Amir Hossein Sadeghian Shahi amirshahi7344@gmail.com 100319475328460012979 100319475328460012979 No School of Paramedical Sciences, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.