Journal of Knowledge & Health1735-577X13220180912The Effect of 8 Weeks Continuous Endurance and High Intensity Interval Training on Cardiac Tissue foxO1 and foxO3a Expression Levels in Male Rats627010.22100/jkh.v13i2.1892FASadafORCID: 0000-0003-3628-5485Kara’i 1Exercise Physiology MSc, Alborz Payam Noor University, Karaj Branch, Iran.. 100af.kara@gmail.comAli AsgharRavasi 2MajidGholipour 3201803032018070820180514 Introduction: The purpose of this study was to investigate the effect of continuous endurance training (CET) and high intensity interval training (HIIT) on the gene expression of foxO1 and foxO3 a in male rats’cardiac tissue.Methods: 18 rats were studied under standard condition. CET protocol was performed 5 sessions per week at 70% VO2 max and HIIT protocolwas performed 3 sessionsper week at 90% VO2 max for two minutes in the first and second weeks and then 110% VO2 max for the rest of the training period. Low intensity intervals were performed at 40% VO2 max for two minutes since the first week to the end of the third week and 30% VO2 max for the rest of the training period. Finally, foxO1 and foxO3a gene expression level were assessed by Real time - PCR and using the formula 2-ΔΔct. The results were evaluated using Kruskal-Wallis test with a significance level of P < 0.05.Results: The results show that compared to control group, CET caused a significant reduction in foxO1 and foxO3a gene expression (both P=0.004). HIIT caused a significant reduction in foxO3a gene expression (P=0.004) but had no significant effect on reduction of foxO1 gene expression level(P=0.055). The levels of genes expression were significantly differed in the two experimental groups (P=0.002).Conclusion: According to the results, both training protocols of the presentstudy may lead to effective training adaptations.