The Effect of High-intensity Interval Training and Moderate-intensity Continuous Training on Oxidative Stress Markers in Left Ventricular Tissue of Male Rats

The present study aimed to assess and compare the effects of high-intensity interval training and moderate-intensity continuous training on oxidative stress-related markers in the left ventricular tissue of the heart muscle in healthy male rats.

Fifteen male Wistar rats, aged 50-70 days, were randomly divided into 3 groups: Control group (CON), high-intensity interval training (HIIT), and moderate-intensity continuous training (MICT). After determining the maximum speed of VO2max, the training program of HIIT (six 2-min periods with 85%-90% VO2max and five 2-min with 50%-60% VO2max intensity) and MICT (same distance of running as HIIT with 70% VO2max intensity) groups were performed for 8 weeks, 5 days per week. Forty-eight hours after the last intervention session, the animals were anesthetized, and their heart tissue was removed and stored at -80°C. Then, the expression rates of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), AMP-activated protein kinase (AMPK), and superoxide dismutase (SOD) genes were measured by real-time PCR, and the concentration of malondialdehyde (MDA) in left ventricular tissue of heart was measured by colorimetry method. One-way analysis of variance and Tukey post hoc test were used for data analysis at the significance level of P<0.05.

There were significant differences between the groups’ expression rates of AMPK, PGC-1α, and SOD (P<0.05). The expression rates of AMPK and PGC-1α were higher in the MICT group than in the CON group (P<0.05). No significant difference was observed between HIIT and MICT groups regarding AMPK and PGC-1α (P>0.05). SOD expression was significantly higher in the HIIT group than CON and MICT groups (P<0.05). SOD expression was also higher in the MICT group compared to the CON group (P<0.05). MDA concentration was not significantly different between the studied groups (P>0.05).

HIIT and MICT induce positive adaptations in the expression of AMPK, PGC-1α, and SOD in the heart tissue of healthy male rats. However, HIIT stimulates SOD gene expression more than MICT.