Open AccessA randomized controlled trial of nitrate supplementation in well-trained middle and older-aged adults
Author(s) -
Michael J. Berry,
Gary D. Miller,
Daniel B. KimShapiro,
Macie S. Fletcher,
Caleb G. Jones,
Zachary D. Gauthier,
Summer L. Collins,
Swati Basu,
Timothy M. Heinrich
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0235047
Subject(s) - placebo , medicine , rating of perceived exertion , randomized controlled trial , nitrite , physical therapy , heart rate , nitrate , blood pressure , chemistry , alternative medicine , organic chemistry , pathology
Purpose Nitrate (NO 3 - ), through its conversion to nitrite (NO 2 - ) 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 NO 3 - rich beverage on submaximal constant work rate exercise time in well-trained middle to older-aged adults. Methods This 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 (NO 3 - rich beverage then placebo or placebo then NO 3 - rich beverage), after which an exercise test at 75 percent of the subject’s maximal work rate was completed. Results The NO 3 - rich beverage increased plasma NO 3 - and NO 2 - levels by 260 μM and 0.47 μM, respectively (p<0.001). Exercise time was not significantly different (p = 0.31) between the NO 3 - rich versus placebo conditions (1130±151 vs 1060±132 sec, respectively). Changes in exercise time between the two conditions ranged from a 55% improvement to a 40% decrease with the NO 3 - rich beverage. Oxygen consumption and rating of perceived exertion were not significantly different between the two conditions. Conclusion In middle to older-aged well-trained adults, NO 3 - supplementation has non-significant, albeit highly variable, effects on exercise tolerance. ClinicalTrials.gov Identifier: NCT03371966