A: Yes! Research has continued to link beets and beetroot juice to performance benefits.
Why beets? Beets and beet juice deliver inorganic nitrate (NO3−), which is then converted in the body to NO. In the body, NO serves many functions related to: increased blood flow, gas exchange, mitochondrial efficiency, and strengthening of muscle contractions. The erogenic (work producing) benefits from beetroot juice are likely related to the functionality of NO in the body.
Studies have concluded that short-term supplementation (three to six days) of beetroot juice supplementation may reduce VO2* at less than or equal to maximum intensity. This may make it possible to increase time-to-exhaustion at less than or equal to maximum (VO2 max) intensity.
Additionally longer-term supplementation (six days or more) with beetroot juice may improve cardiorespiratory performance at the anaerobic threshold and VO2max intensities.
A recent study of trained soccer players showed that six days of beetroot juice resulted in a 3.4% increase in intermittent type exercise performance text.
What about timing? Peak concentration in blood has been found within 2–3 hours of supplementation, with the and the beneficial effects of supplementation with beetroot juice observed at 150 minutes after ingestion. Given the peak concentration timing intake of beetroot juice should be initiated about 90 minutes before the athletic event, workout, or practice.
How much? Research shows about 500 mL of beet root juice to be the beneficial dose of nitrates (6–8 mmol of NO3−). Keep in mind some products are concentrated beet root juice, which means you maybe able to take in small volumes while gaining a similar nitrate dose.
*VO2 is the milliliters of oxygen per your body weight per minute that you can move or utilize
Domínguez, et al. Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review. Journal of Nutrients, January 2017.
Nyakayiru, et al. Beetroot Juice Supplementation Improves High-Intensity Intermittent Type Exercise Performance in Trained Soccer Players. Journal of Nutrients, March 2017.