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Introdaction: Lipid metabolism disorders, especially raised levels of cholesterol and triglycerides increases the risk of atherosclerosis. This study aimed to investigate the effect of training type including submaximal continuous and high-intensity interval training on hepatic gene expression of Apolipoprotein A‐I, and Apolipoprotein A‐II in male Wistar rats.
 
Materials & Methods: This experimental study conducted on 24 male Wistar rats with 8 weeks of age and weight range of 200-250 g. They were randomly assigned into three groups of control (n=8), high-intensity interval training (n=8), and continuous submaximal training (n=8). High-intensity interval training protocol included 30-min interval running 3 days a week for 8 weeks (each interval took 4 min with 85-90% of VO2max and 2-min active recovery with 50-60% of VO2max).  In addition, submaximal continuous training group (30-60 min) was subjected to 50-55% intensity activity with maximum oxygen consumption. Finally, gene expressions of Apolipoprotein A‐I and Apolipoprotein A‐II were measured in this study.
Ethics code: IR.SSRI.REC. 1396, 134.
 
Findings: The findings of this study showed an increase in the gene expressions of Apolipoprotein A‐I in the high-intensity interval (P=0.034) and continuous submaximal training groups (P=0.047), compared to the control group. Moreover, the results of the Bonferroni post-hoc test showed that there was no difference between high-intensity interval and continuous submaximal training groups (P=0.9). In addition, the results of this study showed that there was no significant difference among the three groups in terms of the gene expression of Apolipoprotein A‐II.
 
Discussion & Conclusions: High-intensity interval and continuous submaximal training can play important roles in reducing cardiovascular disease risks, such as atherosclerosis. This is done by increasing hepatic gene expression of Apolipoprotein A‐I and the main factor taking cholesterol from the liver and ultimately the high-density lipoprotein receptor.

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Introduction: Experimental and clinical studies have shown that exercise training is one of the most effective strategies for reducing the progression of cardiomyopathy and decreasing the incidence of cardiovascular complications and mortality due to myocardial ischemia. This study aimed to investigate the role of high-intensity interval training (HIIT) in the expression of Hand2 and Phosphatidylinositol-3-kinase (PI3K) genes in cardiac ischemia rats.
 
Materials & Methods: In this study, 28 male Wistar rats (200-250 g) were randomly divided into four groups of sham, ischemia, exercise, and exercise-ischemia. Myocardial infarction was performed by the closure of the left anterior descending artery for 30 min. In total, 40-min HIIT (each interval consisted of 4-min very high intensity running with approximately 85% to 90% maximum rate of oxygen consumption [VO2_max] followed by 2-min active recovery with approximately 50% to 60% VO2_max) were performed three days a week for eight weeks.
 Ethics code: IR.SSRI.REC.1396.134
 
Findings: The results showed that the expression level of the Hand2 gene in the ischemia-training group was significantly increased, compared to the sham (P=0.001) and ischemia (P=0.001) groups. Furthermore, the concentration of PI3K in the exercise and exercise-ischemia groups was significantly increased, compared to the sham (P=0.001) and ischemia (P=0.001) groups. However, there was a decrease in the ischemia group, compared to the other groups (P<0.05).
 
Discussions & Conclusions: The findings of the present study showed that HIIT leads to increased expression of the Hand2 gene and PI3K. Furthermore, the HIIT results in physiological hypertrophy. On the other hand, the pathological hypertrophy of these variables is reduced in this study.