Background: Telomerase activity plays a key role in preserving telomere length which is important in cellular aging. There is evidence showing the link between sirt6, irisin, and telomerase activity. Aim : The aim of this study was to compare the effect of 8 weeks of high-intensity interval training (HIIT) and aerobic continuous training (ACT) on telomerase activity, sirt6, and irisin levels of healthy older adults. Materials and Methods: Thirty healthy males (age: 60-70 years, weight: 68-72 kg) participated voluntarily to follow the 8-week program including 3 sessions per week. Rest ratio in HIIT training was 1:2 and the intensity corresponded to 90% of HRR. ACT intensity was progressive starting with 50% of HRR and finishing with 70% of HRR. Blood samples were taken in a 12-hour fasting situation, before and after the program. Results: Results showed a significant effect of training on serum telomerase and sirt6 in training groups, not the control group. Also, in comparison to ACT and the control group, serum irisin was significantly higher in the HIIT group. Conclusion: We concluded HIIT training is safe and efficient for older adults in terms of telomerase activity, sirt6, and irisin level and can be followed as a time-efficient training protocol.