Effects of L-citrulline on Oxidative Stress Markers Following High Intensity Interval Exercises in Hypertensive Patients

Background and Objectives: High blood pressure affects nearly 30% of adults. Inactivity and low intake of antioxidants are associated with increased risks of high blood pressure and cardiovascular diseases. High intensity interval exercise increases blood pressure and oxidative stress. The purpose of this study was to investigate effects of L-citrulline consumption on oxidative stress and antioxidant indices after high intensity intervals of hypertensive patients.  Materials & Methods: Subjects of this study included 12 hypertensive men (age 46.54 y ±5.05) who after six d of L-citrulline (6 g) or placebo (6.2 g) intake carried out high intensity interval exercise in crossover manners. High intensity interval exercise sessions consisted eight intervals of 1-min exercise with 80, 85, 90, 95, 100, 105, 110 and 115% of reserve heart rate and active recoveries of 1 min with 35, 40, 45 and 50, respectively. Moreover, 55, 60, 65, 70% of the reserve heart rates were on the bicycle ergometer. Blood samples were collected immediately after exercises and within 90 min of recovery. Results: High intensity interval exercises included significant effects on glutathine peroxidase (p = 0.001), superoxide dismutase (p = 0.001), total antioxidant capacity (p = 0.002) and malondialdehyde (p = 0.001) plasma levels. However, these changes were not significant after placebo and supplement consumptions. Conclusion: Exercise regardless of L-citrulline and placebo intakes decreases oxidative stress and increases antioxidant in hypertensive patients.