Effect of acute and chronic nitrate supplementation on the performance of endurance athletes: a systematic review

Abstract

Evidence that dietary supplementation with nitrate-rich beet juice (NO3-) can improve endurance exercise performance. This paper aimed critically assess the effects of acute and chronic NO3- supplementation in the performance of trained healthy adult individuals and/or athletes. This systematic review analyzed 12 randomized, blinded, crossover clinical trials with control, which investigated the effect of acute and/or chronic supplementation of NO3- through juice or fresh beet on physical performance in endurance exercises. These studies involved 185 subjects. Four of the six acute studies in this review demonstrated improvements in sports performance in running and cycling. Among the eight chronic studies, only two showed no improvement in performance. Six studies with secondary supplementation yield favorable results. Of the six studies conducted with athletes, five demonstrated increases in VO2MAX. The current literature points to the positive effects of dietary supplementation of NO3- acute and chronic in trained and/or athletes. However, there are limitations regarding research on the results of NO3- supplementation in women and if there is an optimal time for observing effects on athletic performance.