New Zealand Blackcurrant Increases Post-Exercise Hypotension Following Sustained Moderate Intensity Exercise

Previous observations demonstrate New Zealand blackcurrant (NZBC) extract to alter cardiovascular responses at rest without prior exercise. However, the prolonged effects of NZBC on blood pressure and heart rate variability (HRV) following exercise are not known. Participants (n15 [5 women], age:31±9 yrs, V̇O2max: 44±9 mL·kg-1·min-1) undertook a control condition of 2-hours of laying supine rest. Subsequently, in a double-blind, placebo controlled, randomised cross-over design participants completed 1-hour of treadmill exercise at 50% V̇O2max followed by 2-hour supine rest with blood pressure and HRV measurement following a 7-day intake of NZBC and placebo (PLA). With NZBC, there was an increase in average fat oxidation (NZBC: 0.24±0.11 vs. PLA: 0.17±0.11 g·min-1, P=0.005), and larger high frequency relative power during the exercise (P=0.037). In the 2-hour rest period, delta change for systolic pressure was larger with NZBC than placebo (Control vs NZBC: -5.6±6.4, Control vs PLA: -3.5±6.0 mmHg, P=0.033), but was not different for diastolic or mean arterial pressure. There were no alterations in HRV variabilities during the 2-hours following the exercise with NZBC. A 7-day intake of NZBC causes a larger post-exercise hypotension response in young, physically active men and women following 1-hour of treadmill exercise at 50% V̇O2max.