moderate intensity continuous training (mict)

Aging is a physiological process that affects heart function. Training is known as a factor accelerating heart output, especially in aged individuals. In the present experimental study, the authors aimed to evaluate how high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) affect autophagy, cardiac remodeling, and cardiac function. 

Twenty-four male Wistar rats, approximately 20 months old, were divided into three groups of control, HIIT, and MICT. The training programs lasted for eight weeks. Aerobic power and training capacity were also assessed. Two-dimensional echocardiography was also applied to assess cardiac indices. At the end of the experiment, tissue sampling of cardiac tissue was applied, and gene expression was assessed using the qRT-PCR technique. Data were analyzed using SPSS software, version 19.

After HIIT and MICT, no significant changes were detected regarding the animal weight. Also, mTORC1, Atg16, and Atg7 gene expression and ejection fraction (EF) and fractional shortening (FS) were accelerated in HIIT and MICT groups compared to control animals. Besides, the collagen type 3 (COLIII) gene expression, left ventricular end-diastolic diameter (LVEDD), and left ventricular end-systolic diameter (LVESD) showed a significant increase (p<0.05) in HIIT and MICT animals than control.

Training can potentially improve cardiac output in older adults. Besides, HIIT seems more effective than MICT.

Aging affects cardiac function and heart output. Regular exercise can improve heart function in old age. This experimental study evaluated the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on cardiomyocyte autophagy and cardiac function.

In this study, 24 older male Wistar rats (>20 months) were divided into three groups of Control, HIIT, and MICT. The animals in the control group received no training, while the HIIT and MICT groups performed high and moderate training intensities at different intervals. Aerobic power and training capacity (VO2max) were also assessed before the training. After eight weeks of training (5 days/week), two-dimensional echocardiography was used for the sonographic assessment of the heart, and the tissue samples of the left ventricle were dissected for assessing gene expression (PGC-1α and FOXO-3α). Data were analyzed using SPSS software, version 19 and presented using Mean±SD. P<0.05 was considered as statistically significant.

The expression of the PGC-1α gene significantly increased, while the FOXO-3α gene expression significantly decreased in the HIIT and MICT groups compared to the control animals (p<0.05). Left ventricle end-systolic dimension decreased (p<0.05), while the left ventricular end-diastolic diameter, ejection fraction, and fractional shortening increased (p<0.05) in the training groups compared to the control animals. These changes were also significant in the HIIT group compared to the MICT group (p<0.05)

HIIT can reduce the expression of autophagy genes and improve cardiac function in aged heart more than MICT.

Hepatokines secreted by the liver play a pivotal role in the pathogenesis of type 2 diabetes, directly influencing glucose and lipid metabolism. Exercise training is recognized as an effective treatment strategy for type 2 diabetes. This study aims to investigate the impact of moderate intensity continuous training (MICT) on the levels of Fetuin-A and tumor necrosis factor-alpha (TNF-α) in type 2 diabetic rats.

Fifteen male Wistar rats aged between 8 and 10 weeks were randomly assigned to three groups (5 rats in each group): healthy control, diabetic, and training diabetic. Diabetes was induced through intraperitoneal injection of nicotinamide and streptozotocin (STZ). The MICT protocol involved eight weeks of continuous running, five days per week, at 55-60% of maximal oxygen consumption. Blood samples were collected 48 hours after the last training session, and serum levels of TNF-α and Fetuin-A were measured.

The observed reductions in Fetuin-A, TNF-α, and glucose levels were not statistically significant in the trained group compared to the diabetic group. However, a significant decrease in insulin levels (p=0.002) and insulin resistance (p=0.01) was observed in the trained group compared to the diabetic group.

In conclusion, moderate intensity continuous training, as a non-pharmacological intervention, appears to play an effective role in the management of type 2 diabetes by improving insulin resistance and reducing insulin levels.