The Effect of Acute and Chronic Moderate and High Intensity Aerobic Exercise on Serum Nitric Oxide in Untrained Overweight Males

Background: The present study aimed at comparing the serum concentration of nitric oxide (NO) after 4 weeks of aerobic activity at 2 different intensities in overweight males. Methods: For this purpose, 20 inactive obese males between 25 and 35 years old were randomly selected as subjects. Their body mass index (BMI) was 29.9  3.04. They were randomly divided to 2 moderate (n = 10) and high (n = 9) intensity groups. They exercised in accordance of specific instructions and were observed by the researcher. Blood samples were collected 3 times: first, in the morning after an overnight fast, second, after the first session, and third, immediately after 4 weeks of exercise. Concentration of nitric oxide serum was measured using the enzyme linked immunosorbent assay (ELISA). Impedance analysis (Body state) was used to determine the body composition. The collected data were analyzed by statistical analysis using dependent t-test and independent t-test analysis. The level of statistical significance was set at P < 0.05. Values were expressed as meanstandard deviation (SD). Results: There was no difference in concentration of nitric oxide serum in the moderate intensity group, after exercise for 4 weeks (P = 1.0). Concentration of nitric oxide serum in the high intensity group was significantly higher after 4 weeks (P = 0.004) and in comparison with the moderate intensity group (P = 0.004). Conclusions: It seems that short-term aerobic activity with moderate intensity does not induce a concentration of nitric oxide serum in overweight males while nitric oxide increases during a similar period at high intensity.