The Effects of Beetroot Juice on VO₂max and Blood Pressure during Submaximal Exercise

Beetroot juice (BR) has been shown to reduce blood pressure (BP) at rest and improve several performance parameters during exercise. However, the effect of BR on BP during submaximal exercise has not been investigated and its effects on VO₂max are inconclusive. The purpose of this study was to investigate the effects of BR on VO₂max and BP during submaximal exercise. 20 healthy, recreationally trained volunteers (age 21.8±2.35 years, weight 75.10±10.62 kg, height 177.4±6.39 cm) participated in this study, which had a double-blind placebo controlled randomized crossover design. Participants supplemented with either 237 ml servings of placebo or 70 ml BR servings (nitrate concentration of 6.4 mmol/day) for 7 days. Participants completed a ramp treadmill protocol to determine VO₂max. BP was taken at 70% max heart rate calculated using the Karvonen method. There was no significant change in VO₂max after BR supplementation (51.07±6.12 ml/kg/min) versus placebo (50.46±6.06 ml/kg/min), t(19)=1.41, p=0.17. There was no significant change in either systolic BP after BR supplementation (180.65±23.37 mm Hg) versus placebo (177.65±22.07 mm Hg), t(19)=0.49, p=0.63, or in diastolic BP after BR (92.90±18.89 mm Hg) versus placebo (90.75±17.73 mm Hg), t(19)=0.51, p=0.62. BR did not affect VO₂max, nor did it affect BP during submaximal exercise.