Sport Physiology & Management Investigations 1735.5354 17 1 2025 05 22 Comparison of two models of high-intensity interval training and moderate-intensity continuous training on genes related to autophagy in heart muscle of elderly rats Comparison of two models of high-intensity interval training and moderate-intensity continuous training on genes related to autophagy in heart muscle of elderly rats 25 37 226506 10.22034/spmi.2025.414278.2515 FA Azadeh Taheri PhD student, Department of Exercise Physiology, Faculty of Literature, Humanities and Social Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran 0000-0002-3609-3996 Mandana Gholami Associate Professor, Department of Physical Education and Sport Sciences, Faculty of Literature, Humanities and Social Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran 0000-0001-8960-4123 Behzad Bazgir Exercise Physiology Research Center, Lifestyle Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran. Hosein Abednatanzi Assistant Professor, Department of Professional Physical Education and Sport Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran 0000-0001-6638-1131 Journal Article 2023 08 31 Aging populations experience increased cardiomyocyte death due to a decline in autophagy, a crucial anti-aging mechanism for cardiac cells. This study compared the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on autophagy-related gene expression in the cardiac muscle of elderly rats. Twenty-four aged male Wistar rats (~20 months old; 350 ± 50 g) were randomized into three groups: control (n=8), MICT (n=8), and HIIT (n=8). The 4-week exercise protocols were as follows: MICT: 5-minute warm-up (30–40% VO₂max), 30-minute continuous running (60–65% VO₂max), and cooldown. HIIT: 30-minute sessions comprising a 5-minute warm-up (30–40% VO₂max), 8 × 3-minute high-intensity intervals (85–90% VO₂max) interspersed with 2-minute active recovery (30–35% VO₂max). Gene expression (FOXO3a, Beclin-1, LC3-II) was quantified via real-time PCR. One-way ANOVA (α = 0.05) revealed: FOXO3a: HIIT significantly upregulated expression vs. control (*p* < 0.05) and MICT; no difference between MICT and control. Beclin-1: Both HIIT and MICT groups exhibited higher expression than control (*p* < 0.05), with no intergroup difference. LC3-II: Both exercise groups surpassed control levels, with HIIT showing greater elevation than MICT. Both HIIT and MICT enhance autophagy-related gene expression in aged rats, suggesting exercise-induced autophagy activation. HIIT demonstrated superior efficacy, particularly in upregulating FOXO3a and LC3-II, implicating its potential advantage for mitigating age-related cardiac autophagy decline. Aging populations experience increased cardiomyocyte death due to a decline in autophagy, a crucial anti-aging mechanism for cardiac cells. This study compared the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on autophagy-related gene expression in the cardiac muscle of elderly rats. Twenty-four aged male Wistar rats (~20 months old; 350 ± 50 g) were randomized into three groups: control (n=8), MICT (n=8), and HIIT (n=8). The 4-week exercise protocols were as follows: MICT: 5-minute warm-up (30–40% VO₂max), 30-minute continuous running (60–65% VO₂max), and cooldown. HIIT: 30-minute sessions comprising a 5-minute warm-up (30–40% VO₂max), 8 × 3-minute high-intensity intervals (85–90% VO₂max) interspersed with 2-minute active recovery (30–35% VO₂max). Gene expression (FOXO3a, Beclin-1, LC3-II) was quantified via real-time PCR. One-way ANOVA (α = 0.05) revealed: FOXO3a: HIIT significantly upregulated expression vs. control (*p* < 0.05) and MICT; no difference between MICT and control. Beclin-1: Both HIIT and MICT groups exhibited higher expression than control (*p* < 0.05), with no intergroup difference. LC3-II: Both exercise groups surpassed control levels, with HIIT showing greater elevation than MICT. Both HIIT and MICT enhance autophagy-related gene expression in aged rats, suggesting exercise-induced autophagy activation. HIIT demonstrated superior efficacy, particularly in upregulating FOXO3a and LC3-II, implicating its potential advantage for mitigating age-related cardiac autophagy decline. https://www.sportrc.ir/article_226506_8a3e03202fb19e568b56f1f855911e27.pdf