Does nitrate improve exercise tolerance and exercise capacity in people with chronic obstructive pulmonary disease (COPD)?

Current evidence shows that nitrate supplementation can lower subjective perceptions of exertion during exercise in people with chronic obstructive pulmonary disease (COPD).^[1] Therefore, nitrate might improve exercise tolerance in this population. However, while some trials have found that nitrate/beetroot juice can increase the distance people with COPD can walk,^[2][3][4] all of the current evidence compiled in systematic reviews and meta-analyses shows large variability in the effect of nitrate on exercise capacity between studies.^[5][1][6] Consequently, while there is potential for nitrate supplementation to improve exercise capacity in people with COPD, further high-quality randomized controlled trials are needed to fully understand its efficacy.^[5][1][6]