Effect of Acute Dietary Nitrate Supplementation on the Post-Exercise Ambulatory Blood Pressure in Obese Males: A Randomized, Controlled, Crossover Trial.

This study aimed to verify the effect of beetroot juice on post-exercise ambulatory blood pressure (BP) in obese individuals. Fourteen non-hypertensive obese males were randomly assigned to three experimental sessions: 1) Beetroot juice with exercise (BJE, 200ml with ≈ 800mg nitrate and 40 minutes of moderate-intensity aerobic exercise at an intensity of 50% of the heart rate reserve), 2) fruit soda with exercise (FSE, 200ml of a low-nitrate drink and the same exercise session) and 3) control (CON, 200ml of water, an insignificant nitrate drink without exercise). The concentration of total nitrites and nitrates in plasma (NOx) after the drinks and the 24-hour ambulatory BP were evaluated. A two-way (condition vs. time) ANOVA for repeated measures, with a Bonferroni post hoc was used to analyze variables. The plasma NOx concentration increased significantly after ingestion of beetroot juice (from 9.9 ± 8.4 μM to 47.0 ± 16.9 μM, p < 0.001) and remained elevated until 1 hour post-intervention (54.7 ± 10.1 μM, p < 0.001), while it did not change in FSE and CON groups. The BJE session decreased ambulatory systolic BP in 5.3 mmHg (IC95%, -10.1 to -0.6, p = 0.025) in the period of 1-6 h after the BJE session compared to the CON session and reduction of 3.8 mmHg (IC95%, -7.5 to -0.007, p = 0.05) compared to the FSE session. No significant changes were observed for ambulatory diastolic BP (p > 0.05). BJE enhanced the reduction of systolic ambulatory BP up to 6 hours following a moderate-intensity aerobic exercise in obese individuals with an elevated cardiovascular risk profile.