Background and Aim: Aging and the progressive effects of sarcopenia on muscle tissue, coupled with its synergy with obesity, highlight the increasing role of myostatin as a key factor in muscle atrophy and inter-tissue interactions. Physical exercise may influence these pathways. This study aimed to evaluate the impact of eight weeks of resistance training and high-intensity interval training (HIIT) on the strength of the lower limb muscles and myostatin levels in the visceral fat, soleus muscle, and serum of obese, aged male rats. Methods: This experimental study involved 40 male Wistar rats (mean age: 15 months, weight: 320–350 grams). Ten rats were designated as the control group, while the remaining 30 underwent a high-fat diet for 12 weeks to induce obesity. Obese rats, with a Lee Index greater than 310, were divided into three groups: obese control, HIIT, and resistance training. The training regimen lasted eight weeks with three weekly sessions. The resistance training group performed exercises with weights corresponding to 25%, 50%, 75%, and 100% of body weight on a ladder. The HIIT group performed treadmill intervals at 85% (high intensity) and 50% (low intensity) of maximum speed in 2-minute intervals. Forty-eight hours after the final training session, tissue samples from the soleus muscle, serum, and visceral fat were collected. Results: Significant differences in myostatin protein levels in the soleus muscle, visceral fat, and serum were observed between the control and exercise groups (P<0.05). Post-hoc analysis revealed that myostatin levels in the obese control group were significantly higher than those in the exercise and non-obese control groups across all measured tissues (P<0.05). While myostatin levels were lower in the resistance training group compared to the HIIT group, this difference was not statistically significant. Both training modalities reduced myostatin levels relative to the obese control group, although the reduction was not sufficient to bring levels closer to those of the non-obese control group. Conclusion: Both resistance training and high-intensity interval training, through distinct mechanical and metabolic stressors, significantly reduced myostatin expression in various tissues. These findings suggest that physical exercise, regardless of modality, represents an effective approach to mitigate the rate of muscle atrophy associated with aging and sarcopenic obesity.

Background: The most common causes of mortality in patients with diabetes mellitus are cardiovascular disorders; and one of their reasons is inflammatory factors. Given that physical activity can reduce inflammation, the present study aimed to investigate the effects of two types of progressive resistance training (RT) and high-intensity interval training (HIIT) on the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κ B) gene and serum levels of tumor necrosis factor-alpha (TNF-α ) in male diabetic rats. Methods: In this experimental study, 72 male rats were divided into 6 groups of 12 diabetic rats, control, diabetic + intensity interval training (DIIT), HIIT, diabetic + resistance training (DRT), and RT. Progressive resistance training was performed in 6 week, 3 sessions per week, as climbing a vertical ladder with additional weights of 50%, 75%, 90%, and 100% the body weight of the animals. After successful completion, 30 grams were added to the weights, to the extent that the rats could not carry the ladder. HIIT were also performed at in 6 week, 3 sessions per week, with an intensity of 50% to 110% of the VO2max. 24 hours after the completion of the training, the hand grip and time to exhaustion functional test was taken, and the animals were autopsied 48 hours after the test. Finally, the expression of NF-κ B gene was evaluated using real-time polymerase chain reaction (real-time PCR) technique and ANOVA statistical test. Findings: The expression of NF-κ B gene in HIIT group increased more than RT group (P = 0. 0007), and serum TNF-α decreased significantly after both types of exercise in HIIT group (6/13) which was more obvious. Conclusion: 6 weeks of HIIT and RT training can play an important role in significantly reducing inflammation, and adapting to strength and endurance.

Background and Objective: Exercise has many effects on human health, one of which is to help angiogenesis and prevent cardiovascular disease. The aim of this study was to investigate the effect of three training methods Moderate-Intensity Aerobic Exercise Training (MIT), High Intensity Training (HIT) and High-intensity interval training (HIIT) on the expression of HGF and PlGF genes, which are important factors involved in angiogenesis. Materials and Methods: In this study, 32 male Wistar rats with an average weight of 300 grams were randomly divided into four groups including control, MIT, HIT and HIIT (n=8) and underwent exercise for an eight-week period. 48 hours after the last training session, samples were taken from adipose tissue of rat and the expression of HGF and PlGF genes in them was determined using Real time PCR. Statistical analysis of data was performed using SPSS and Kruskal-Wallis and Hodges-Holmes tests software. Results: The results showed that all three training methods MIT, HIT and HIIT increase the expression of HGF and PlGF genes (P <0. 05). However, there is no significant difference between the three exercise methods (P> 0. 05). Conclusion: MIT, HIT and HIIT exercises have favorable effects in increasing the expression of HGF and PlGF genes.

Background: Moderate intensity continuous training (MICT) has been reported as an effective exercise on bone metabolism. However, very few studies have focused on high-intensity interval training (HIIT). The aim of this study was to investigate and compare the effects of HIIT and MICT training on bone density in middle-aged rats. Methods: 30 male Wistar rats (16 weeks old) were randomly divided into three groups: control, MICT and HIIT. Both test groups completed 8 weeks (5 sessions per week) of treadmill training in which the HIIT group performed 10 sessions of running at a speed of 35-47 m/min with a 2-minute active recovery, and the HIIT group ran continuously for 10-45 minutes at a speed of 15-20 meters per minute. The body composition and bone mineral density in the whole body were evaluated through Dual Xray absorptiometry (DXA) at the beginning and after the intervention. The data was analyzed using SPSS software and one-way analysis of variance and Tukey's post hoc tests. Results: After 8 weeks of intervention, BMD of the whole body and femur increased significantly in both groups (p0≥, 0. 05), although the observed change was greater in the HIIT group (p≥, 0. 05). In addition, in the case of BMD of the lumbar vertebra, no significant difference was observed between all three groups after the intervention (p≤, 0. 05). Conclusion: These findings show that a period of HIIT and MICT training can improve bone density in middle-aged rats and compared to MICT, HIIT had more benefits on bone density.