Short-term effects of nitrate-rich beetroot extract supplementation on blood pressure indices and intense intermittent exercise performance in healthy males

The effects of nitrate-rich beetroot extract (BRE) on blood pressure (BP) indices and intense intermittent exercise performance have yet to be examined. To investigate the short-term (5-day) effects of BRE supplementation on resting blood pressure (BP), nitric oxide (NO) bioavailability, blood hemoglobin, blood glucose, cognitive task (Stroop test), and intense intermittent exercise performance (Yo-Yo Intermittent Recovery Level 1 test; YYIRTL1) performance. In a double-blind, randomized, crossover manner, 18 healthy males received beetroot extract (BRE; 500 mg·kg"1·day"1) and placebo (PLA) for 5 days, with a washout period of 10 days separating each trial. The total length covered in the YYIRTL1 was not statistically different during the BRE (783 ± 388 m) compared to the PLA (737 ± 357 m) trial (P > 0.05). Systolic blood pressure was lower in the beetroot extract condition (BRE: 113 ± 12 mmHg) compared to the placebo (PLA: 122 ± 12 mmHg) and control (CON: 123 ± 12 mmHg) conditions (P < 0.05), with no significant main effect for supplementation for diastolic blood pressure (P > 0.05). Mean arterial pressure was reduced in the BRE condition (88 ± 3 mmHg) compared to the placebo (PLA: 92 ± 2 mmHg). Performance in the Stroop test was ~9.53% and ~ 8.45% faster at rest and during YYIRTL1 with BRE compared to PLA, respectively. The current results indicate short-term nitrate-rich supplements, in a form of beetroot extract, may not be ergogenic for intense intermittent exercise as the supplementation failed to improve intense intermittent exercise performance. Nevertheless, short-term BRE intake can be a highly practical blood pressure management strategy.