Effects of nitrate supplementation on running performance: a systematic review

Introduction: Nitrate supplementation has been shown to be effective in improving physical performance. Such results are mainly due to the vasodilating effect of nitric oxide, produced endogenously from dietary nitrate. However, the literature is still conflicting about the effects of this supplementation depending on the type of exercise tested. Objective: To analyze the effects of nitrate supplementation on performance in running exercises. Materials and Methods: Studies were identified and selected from PubMed and Google Scholar databases by March 30, 2022. Triage and eligibility of studies were performed by two independent evaluators, following the PICOS strategy. Eligible articles had their methodological quality assessed through the application of the PEDro scale and the risks of bias were identified by Risk of Bias 2.0. Results: Initially, 56 studies were identified, and, after qualitative analysis, ten studies were included. Of these, five verified the effects of nitrate supplementation in time trial races, four in races to exhaustion and one study in both protocols. According to the studies reviewed, nitrate supplementation determined positive effects in races to exhaustion and in short distances in time trial running, as well as increased mean velocity at maximal aerobic power in subjects with low or moderate aerobic fitness. Conclusion: Nitrate supplementation appears to be an alternative for healthy young men to practice short distance running, as well as to increase time to exhaustion.