The supplement nitrate is better known as beetroot juice. Beetroot is naturally rich in nitrate, while it’s far from the only plant source, it is the most practical to juice and takes in. The main benefit of sports performance is that reduces oxygen costs and can, therefore, prolong activity. It is found most beneficial for exercises 1-10min, but also longer aerobe exercises can benefit from this supplement.
Performance benefits seem to be more pronounced in rocky athletes and less visible in well-trained athletes.
High nitrate-containing foods are leafy green and root vegetables like spinach, rocket salad, celery, beetroot. You could start eating these plant sources more frequently, but it is much more convenient to just take a supplement. Usually, they come in the form of a highly concentrated juice. Acute performance benefits are seen within 2-3 hours after ingestion of 6.4-12.8mg/kg nitrate.
Apart from having a not so tasty flavor, there are very few side effects. However, there might be some gastrointestinal upset, therefore nitrate should first be trained in training.