PLoS ONE (Jan 2020)
A randomized controlled trial of nitrate supplementation in well-trained middle and older-aged adults.
Abstract
PurposeNitrate (NO3-), through its conversion to nitrite (NO2-) and nitric oxide, has been shown to increase exercise tolerance in healthy younger adults and older diseased patients. Nitrate's effect in well-trained middle to older-aged adults has not been studied. Therefore, the purpose of this investigation was to examine the effects of a NO3- rich beverage on submaximal constant work rate exercise time in well-trained middle to older-aged adults.MethodsThis was a randomized controlled cross-over trial with 15 well-trained middle to older-aged adults, 41-64 year-old, who received one of two treatments (NO3- rich beverage then placebo or placebo then NO3- rich beverage), after which an exercise test at 75 percent of the subject's maximal work rate was completed.ResultsThe NO3- rich beverage increased plasma NO3- and NO2- levels by 260 μM and 0.47 μM, respectively (pConclusionIn middle to older-aged well-trained adults, NO3- supplementation has non-significant, albeit highly variable, effects on exercise tolerance. ClinicalTrials.gov Identifier: NCT03371966.