effect of high-intensity interval training on apoptotic gene expression in rat myocardial tissue

Background: excessive apoptosis in the myocardium contributes to the pathogenesis of heart disease. evidence indicates that high-intensity interval training (hiit) can alter myocardial apoptosis-related signaling. objectives: the purpose of the study was to investigate the effect of 12 weeks of hiit on some indices of apoptosis, including bcl-2, bax, and caspase-3 in the myocardial tissue of male rats. methods: thirty male wistar rats (age range: 8 - 10 weeks) were randomized into three groups, including sham (n = 10), control (n = 10), and hiit (n = 10). the experimental group underwent hiit consisting of 2 - 8 repetitions of 4-min high-intensity intervals (85% - 90% peak speed) interspersed with low-intensity intervals (45% - 50% peak speed), performed five times/week over 12 weeks. forty-eight hours after the last training session, animals’ hearts were removed. the gene expressions of bcl-2, bax, and caspase-3 were analyzed by the rt-pcr method. the independent t-test was used for statistical analysis (p < 0.05). results: the gene expressions of bcl-2 and bcl-2/bax ratio were higher in the training group than in the control group (p = 0.001 and p = 0.002, respectively). regarding bax and caspase-3 gene expression, although the mean levels were lower in the exercise group than in the control group, the differences were statistically insignificant (p = 0.57 and p = 0.27, respectively). conclusions: overall, it seems that hiit significantly increases the expression of anti-apoptotic indicator bcl-2 and the ratio of bcl-2/bax in the myocardium of male rats. however, further studies are needed to show the effects of hiit on myocardial apoptosis.