Trial reportPloS one2015
Acute Dietary Nitrate Supplementation and Exercise Performance in COPD: A Double-Blind, Placebo-Controlled, Randomised Controlled Pilot Study.
Trial report in PloS one, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 24 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
24 citing papers in PubMed, 3 syntheses or guidelines pooled it, 54 citations in OpenAlex.
- Plasma nitrate, dietary nitrate, blood pressure, and vascular health biomarkers: a GRADE-Assessed systematic review and dose-response meta-analysis of randomized controlled trials.Nutrition journal · 2025Pooled it
- Ergogenic Effect of Nitrate Supplementation in Clinical Populations: A Systematic Review and Meta-Analysis.Nutrients · 2024Pooled it
- Impact of dietary nitrate supplementation on exercise capacity and cardiovascular parameters in chronic respiratory disease: a systematic review and meta-analysis.BMJ open respiratory research · 2021Pooled it
- Oral nitrate supplementation improves cardiovascular risk markers in COPD: ON-BC, a randomised controlled trial.The European respiratory journal · 2024Trial
- Trial
- A Single Dose of Beetroot Juice Does Not Change Blood Pressure Response Mediated by Acute Aerobic Exercise in Hypertensive Postmenopausal Women.Nutrients · 2019Trial
- Effect of Acute Dietary Nitrate Supplementation on the Post-Exercise Ambulatory Blood Pressure in Obese Males: A Randomized, Controlled, Crossover Trial.Journal of sports science & medicine · 2019Trial
- Dietary beetroot juice - effects on physical performance in COPD patients: a randomized controlled crossover trial.International journal of chronic obstructive pulmonary disease · 2017Trial
- Submaximal 2-day cardiopulmonary exercise testing to assess exercise capacity and post-exertional symptom exacerbation in people with long COVID.Experimental physiology · 2026Article
- Dietary Beetroot Juice - Effects in Patients with COPD: A Review.International journal of chronic obstructive pulmonary disease · 2024Review
- Effects of short-term dietary nitrate supplementation on exercise and coronary blood flow responses in patients with peripheral artery disease.Frontiers in nutrition · 2024Article
- Acute beetroot juice consumption does not alter cerebral autoregulation or cardiovagal baroreflex sensitivity during lower-body negative pressure in healthy adults.Frontiers in human neuroscience · 2023Article
- Dietary Inorganic Nitrate as an Ergogenic Aid: An Expert Consensus Derived via the Modified Delphi Technique.Sports medicine (Auckland, N.Z.) · 2022Article
- Nutritional Status and Body Composition in Patients Suffering From Chronic Respiratory Diseases and Its Correlation With Pulmonary Rehabilitation.Frontiers in rehabilitation sciences · 2021Review
- Functional properties of beetroot (Nutrition & metabolism · 2020Review
- Review
- A Narrative Review on the Potential of Red Beetroot as an Adjuvant Strategy to Counter Fatigue in Children with Cancer.Nutrients · 2019Review
- PPARα-independent effects of nitrate supplementation on skeletal muscle metabolism in hypoxia.Biochimica et biophysica acta. Molecular basis of disease · 2019Article
- Beetroot juice alleviates isoproterenol-induced myocardial damage by reducing oxidative stress, inflammation, and apoptosis in rats.3 Biotech · 2019Article
- Metabolomic and lipidomic plasma profile changes in human participants ascending to Everest Base Camp.Scientific reports · 2019Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
9 authors at 5 institutions in 1 country.
Funding
Abstract
backgroundDietary nitrate supplementation can enhance exercise performance in healthy people, but it is not clear if it is beneficial in COPD. We investigated the hypotheses that acute nitrate dosing would improve exercise performance and reduce the oxygen cost of submaximal exercise in people with COPD.
methodsWe performed a double-blind, placebo-controlled, cross-over single dose study. Subjects were randomised to consume either nitrate-rich beetroot juice (containing 12.9 mmoles nitrate) or placebo (nitrate-depleted beetroot juice) 3 hours prior to endurance cycle ergometry, performed at 70% of maximal workload assessed by a prior incremental exercise test. After a minimum washout period of 7 days the protocol was repeated with the crossover beverage.
results21 subjects successfully completed the study (age 68 ± 7 years; BMI 25.2 ± 5.5 kg/m2; FEV1 percentage predicted 50.1 ± 21.6%; peak VO2 18.0 ± 5.9 ml/min/kg). Resting diastolic blood pressure fell significantly with nitrate supplementation compared to placebo (-7 ± 8 mmHg nitrate vs. -1 ± 8 mmHg placebo; p = 0.008). Median endurance time did not differ significantly; nitrate 5.65 (3.90-10.40) minutes vs. placebo 6.40 (4.01-9.67) minutes (p = 0.50). However, isotime oxygen consumption (VO2) was lower following nitrate supplementation (16.6 ± 6.0 ml/min/kg nitrate vs. 17.2 ± 6.0 ml/min/kg placebo; p = 0.043), and consequently nitrate supplementation caused a significant lowering of the amplitude of the VO2-percentage isotime curve.
conclusionsAcute administration of oral nitrate did not enhance endurance exercise performance; however the observation that beetroot juice caused reduced oxygen consumption at isotime suggests that further investigation of this treatment approach is warranted, perhaps targeting a more hypoxic phenotype.
trial registrationISRCTN Registry ISRCTN66099139.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.