The Effect of 6 Weeks of High Intensity Interval Training (HIIT) on Plasma Levels of Apelin and Nitric Oxide in Inactive middle Aged Men

Vasodilators are one of the key regulators of blood pressure and cardiovascular system. The aim of this study was to evaluate the effect of high intensity interval training on apelin and nitric oxide changes as vasodilators and regulators of blood pressure. In this study, apelin and nitric oxide were measured before and after 6 weeks of interval training. For this purpose, 2 groups: experimental (n=10) and control (n=10) of middle aged men (age range 45-55) in Tehran city were randomly selected. High intensity interval training protocol consisted of 10 intervals (45 seconds with 85-90% of heart rate reserve and 2 minutes of recovery) which was performed by the experimental group in 6 weeks. At the end of the third week, intensity of training increased to 12 training intervals and 90 seconds of recovery. 48 hours after the last training session, blood samples and anthropometric measures and body composition were taken. The results showed that 6 weeks of high intensity interval training intervention significantly increased apelin (P=0.001) and nitric oxide (P=0.001) while it significantly reduced systolic (P=0.001) and diastolic (P=0.002) blood pressures in the experimental group. The results indicated the beneficial effect of exercise on apelinergic system and blood pressure and also showed that those with high blood pressure may have high intensity interval activity. However, this idea requires further research on the role of high intensity interval training and its relationship with blood pressure.