Vesnu Publications (Farzanegan Radandish) Journal of Exercise & Organ Cross Talk 2783-2074 Articles in Press 2026 09 01 Effects of eight weeks of resistance training and vitamin D supplementation on insulin resistance, glycemic control, and inflammatory markers in men with type 2 diabetes: A single blind randomized controlled trial 147 155 245165 10.22122/jeoct.2026.583128.1205 EN Sepideh Salimi Department of Physical Education and Sport Sciences, SR.C., Islamic Azad university, Tehran, Iran. SeyedSepehr Mousavi Department of Physical Education and Sport Sciences, SR.C., Islamic Azad university, Tehran, Iran. 0009-0000-0989-8484 Asal Mohammadi Department of Physical Education and Sport Sciences, SR.C., Islamic Azad university, Tehran, Iran. 0009-0006-9527-1410 Mohammad Hadi Pourramezan Department of Exercise Physiology, Sport Sciences Research Institute, Tehran, Iran. 0009-0005-5453-6323 Sara Yazdan Mehr Department of Physical Education and Sport Sciences, SR.C., Islamic Azad university, Tehran, Iran. Anahita Sarrafpour Habibi Department of Physical Education and Sport Sciences, SR.C., Islamic Azad university, Tehran, Iran. 0009-0007-2854-4252 Journal Article 2026 04 24 This study aimed to investigate the effects of eight weeks of resistance training (Ex), vitamin D supplementation (VD), and their combination (VD+Ex) on insulin resistance (HOMA IR), glycemic control (HbA1c, fasting glucose), inflammatory markers (interleukin 6 [IL 6] and C reactive protein [CRP]), and anthropometric measures in men with T2DM. In this single blind randomized controlled trial, 40 men with T2DM (aged 40–55 years) were randomly allocated into four groups (n=10 each): placebo control (PI), vitamin D supplementation (2000 IU/day, VD), resistance training (three sessions/week, 60–70% of 1RM, progressive overload, Ex), and combined VD+Ex. All participants maintained their usual diet, lifestyle, and anti-diabetic medications. Fasting blood samples were collected pre and post intervention to measure serum glucose, insulin, 25 hydroxy vitamin D, IL 6, and CRP. HOMA IR was calculated. Post hoc analysis showed that the Ex group had significantly lower HOMA IR than the placebo group (p=0.002), and the VD+Ex group had significantly lower HOMA IR compared to both placebo (p<0.001) and VD alone (p=0.001). The comparison between VD+Ex and Ex was not statistically significant (p>0.05). No significant difference in HbA1c was observed (p=0.210). For body fat percentage, both Ex (p=0.043) and VD+Ex (p<0.001 vs. placebo;p=0.009 vs. VD) showed significant reductions. IL 6 levels were significantly lower in the Ex and VD+Ex groups compared to placebo and VD groups (p<0.001 for both). No significant changes were found in CRP levels (p=0.078). The combination of resistance training and vitamin D did not provide additional statistically significant benefits over resistance training alone for any outcome, including HOMA IR, body fat percentage, or IL 6.