# Beetroot in sport: why the decisive step happens in your mouth

> Nitrate from beetroot is among the best-studied substances in sports nutrition. How the enterosalivary circuit works, who actually benefits - and why mouthwash destroys the effect.

For decades nitrate was treated as a contaminant in drinking water. Today nitrate from vegetables is one of the best-evidenced compounds in sports nutrition. The decisive step happens neither in the muscle nor in the liver - it happens on your tongue.

## The enterosalivary circuit

Beetroot is among the most nitrate-rich vegetables there is. After drinking, nitrate is absorbed in the small intestine, and roughly a quarter is actively transported into the salivary glands and concentrated there. In the mouth, facultative anaerobic bacteria on the back of the tongue - mainly Veillonella and Actinomyces - do the work: they reduce nitrate to **nitrite**. Humans have no enzyme of their own for this step.

Once swallowed, nitrite meets stomach acid and is further reduced to **nitric oxide (NO)**. This pathway works independently of nitric oxide synthase - and better when oxygen is scarce and pH is low, exactly the situation inside a working muscle.

## What that does, measurably

Larsen et al. (2007) gave healthy subjects nitrate for three days: oxygen cost during submaximal exercise fell by around 5 percent - at identical power output.

Bailey et al. (2009) repeated this with beetroot juice: lower O2 cost and a 16 percent longer time to exhaustion during high-intensity exercise. The proposed mechanisms are more efficient mitochondrial coupling and a lower ATP cost of calcium handling in the muscle.

## Who benefits - and who benefits less

Jones (2014) summarises it: effects are clearest in recreational and moderately trained people, while in elite athletes with very high VO2max they shrink or disappear - their baseline NO turnover is already high. Nitrate works most reliably for efforts of 5 to 30 minutes and under low oxygen availability, such as at altitude.

## Dose, timing - and the mouthwash mistake

Effective doses start at roughly 6 mmol of nitrate. Plasma nitrite peaks 2 to 3 hours after intake - so you take it two to three hours before the effort. Loading over several days works more reliably than a single dose.

Govoni et al. (2008) demonstrated the most common user error: an antibacterial mouthwash sharply blunted the rise in plasma nitrite. Chlorhexidine kills exactly the bacteria you need for the first reduction step.

## How WOO® Randenpulver puts this into practice

[WOO® Randenpulver](/en/shop/woo-beetroot-powder-bag) is 100 % freeze-dried Swiss organic beetroot, no additives. In freeze-drying, frozen water sublimates under vacuum at low temperature - up to 98 % of the nutrients are retained. That matters here because the red **betalains** are sensitive to heat and light: cooking degrades them measurably. Clifford et al. (2015) describe their antioxidant properties.

One scoop (8 g) in 200 ml of water, 30 servings per tin. The authorised claims here concern folate: it contributes to normal cell division and to the normal function of the immune system. For dietary nitrate and nitric oxide there are no EFSA-authorised claims - the evidence base and the regulatory status are two different things.

## Frequently asked questions

**My urine turned red - is that a problem?**
No. The phenomenon is called beeturia and affects 10 to 15 percent of people. It is caused by the pigment betanin, which is excreted unchanged.

**Is one serving before a race enough?**
A single dose 2 to 3 hours beforehand works, loading over three to six days is more reliable. Test both in training, never for the first time on race day.

**Why no mouthwash afterwards?**
Because it eliminates the nitrate-reducing bacteria on your tongue and interrupts the conversion to nitrite - which removes most of the effect.

## Sources

Larsen FJ et al. (2007), Acta Physiologica - Effects of dietary nitrate on oxygen cost during exercise.
Bailey SJ et al. (2009), Journal of Applied Physiology - Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise.
Jones AM (2014), Sports Medicine - Dietary nitrate supplementation and exercise performance.
Govoni M et al. (2008), Nitric Oxide - The increase in plasma nitrite after a dietary nitrate load is markedly attenuated by an antibacterial mouthwash.
Clifford T et al. (2015), Nutrients - The potential benefits of red beetroot supplementation in health and disease.

*WOO® Randenpulver - in the NEMAPO shop.*