Ban the beets?
The hot new performance-enhancing drug is…beetroot juice!? (original paper)
Nitrates in food reduces the oxygen cost of some forms of exercise and improves high-intensity exercise tolerance. So the researchers gave half a litre of beetroot juice (which is rich in nitrate) or a nitrate depleted placebo to club-level competitive cyclists. The nitrate juice produced better cycling performance when compared to the placebo. On a 16.1 km race beet juice reduced the total time by 2.7% – not much, but presumably enough to matter in a competition.
In any case, this is fun for doping discussions. Should we ban athletes from quaffing beet juice?