Beetroot juice has been shown to improve stamina during exerciseWestend61/Getty Images
My friend Lizzie, a very athletic doctor, recently showed me some concentrated beetroot shots she was planning to take before an upcoming marathon. I never run anywhere, but she let me try one anyway. I could only manage slow sips of the intensely beetroot-tasting purple liquid, but she assured me it has a raft of benefits for athletes and non-athletes alike. I decided to look into it.
Most beetroot research, I discovered, has been led by Andy Jones, an exercise physiologist at the University of Exeter, UK. His team’s interest in the humble root vegetable arose because it is a natural source of nitrate. In the body, nitrate is converted to nitric oxide, an important signalling molecule that causes blood vessels to widen. This widening reduces blood pressure and allows more oxygen-rich blood to flow into working muscles.
In their first beetroot study, published in 2009, Jones and his colleagues asked eight recreational athletes to cycle hard for as long as possible. They lasted about a minute-and-a-half longer, on average, when they had consumed beetroot juice daily for six days beforehand, compared with when they had blackcurrant juice.
