Other products exist which utilise the above pathway, with nitrate supplements (typically in the form of beetroot) being the most prominent. Nitrate supplementation is able to increase serum nitrite levels, and this can in turn increase nitric oxide levels.
Nitrate supplementation (from beetroot) has been shown to improve performance in running, cycling and swimming, and nitrate supplementation in an isolated form has been shown to improve crossfit performance, making it something worth considering for continuous-effort baseda ctivities.