Study
The researchers got 11 fit subjects to run a distance of 5 km on a treadmill on two occasions. On one occasion they did so 75 minutes after eating 200g cooked beets – representing 500 mg nitrate – on the other occasion they did so after eating a placebo containing the same amount of kcals but no nitrate.
Faster
And indeed: the subjects ran faster after eating beetroot. The performance enhancing effect was present over the whole course, but it was only statistically significant over the last 1800 m.
Conclusion
The researchers think that vegetables that are naturally high in nitrates are a good alternative for nitrate-rich supplements. "Although more isolated forms of dietary nitrates (e.g. sodium nitrate) also have ergogenic effects, their long-term safety is questionable", they write. "Although these findings should be confirmed in elite athletes and in exercise tasks of different durations (e.g. marathon running) and modes (e.g. rowing or swimming), they have obvious implications for food and nutrition practitioners in the area of sports nutrition and athletes."
"In addition, these findings might have relevance in clinical dietetics if the ergogenic effects of nitrate-rich vegetables also benefit individuals with compromised functional capacity such as patients with heart failure and frail elderly persons."
"From a practical perspective, evidence from our study suggests that for ergogenic effects, 200 g baked beetroot, or an equivalent nitrate dose from other vegetables, should be consumed approximately 60 minutes before exercise."