Supplements
quercetin improves exercise performance
In plain terms: Does quercetin improve endurance or athletic performance?
Part of: 🧪 quercetin
Only in a sense that doesn't matter. Pooled trials do show an effect, but it's about 1% and only in untrained people; in trained athletes it's flatly nothing. That's too small to feel, let alone race on.
📅 Last reviewed: 2026-07-26 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Human trials (RCT / n-of-1)
How the studies fall
What the evidence shows
Statistically detectable, practically irrelevant. Two quercetin-specific meta-analyses (11 and 7 RCTs) do find significant pooled effects — but the effect size is ES = 0.15, which the authors themselves call trivial, amounting to something like 0.15-2% on VO2max or endurance. The 2013 synthesis shows it plainly: significant in untrained subjects (0.83%, p=.02) and flatly null in trained ones (0.
The evidence (12)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Nieman DC et al 2010 · Medicine and science in sports and exercise | RCT | supports | low | RCT crossover, untrained young males (n=26, VO2max ~46 mL/kg/min), 1000 mg/d x 2 wk; 12-min treadmill TT distance change was +2.9% with quercetin vs -1.2% placebo (29.5±11.5 vs -11.9±16.0 m, p=.038), with only non-significant trends in mito |
| Kurtz JA et al 2024 · study_type: RCT | RCT | contradicts | high | RCT, 48 highly trained cyclists, quercetin 500mg/d and/or citrulline 3000mg/d BID for 28 days before a 20km cycling time trial; combined QCT+CIT gave no benefit on TT performance or other performance measures (power, RER, RPE). VO2 improved |
| Kressler J et al 2011 · Medicine and science in sports and exercise | meta-analysis | mixed | moderate | MA of 11 quercetin RCTs (n=254, dose ~1000 mg/d, ~11 d median); combined VO2max/endurance effect size ES=0.15 (p=.021, 95% CI 0.02-0.27), a ~2% improvement judged 'trivial to small', with no significant difference by outcome type or by base TEMPERED: the pooled effect is ES=0.15 — the authors' own word is 'trivial' — and it is null in trained people. A direction-only reading would overstate a ~1% change. |
| Bourdas DI et al 2024 · study_type: RCT | RCT | mixed | moderate | Double-blind crossover RCT, 38 high-level (trained) male basketball players, single pre-exercise dose of mangiferin 84mg + quercetin 140mg combo (not quercetin alone); improved mean circuit time (18.17 vs 20.31s POST vs PRE, p=0.013) and lo TEMPERED: quercetin co-administered with mangiferin — the effect cannot be attributed to quercetin. |
| Davis JM et al 2010 · International journal of sport nutrition and exercise metabolism | RCT | supports | low | RCT crossover, untrained adults (n=12), 500 mg BID x 7 d; VO2max rose 3.9% vs placebo (p<.05) and bike time-to-fatigue rose 13.2% (p<.05) — very small sample. |
| Dener B et al 2025 · study_type: observational | observational | mixed | low | Narrative review (no new data, no effect sizes) states quercetin's effects on athletic performance are 'contradictory' across studies while asserting overall positive effects on endurance performance and anti-inflammatory parameters. |
| Somerville V et al 2017 · Sports medicine (Auckland, N.Z.) | meta-analysis | mixed | moderate | MA of 14 polyphenol-performance RCTs (predominantly trained males, mean dose 688±478 mg/d); overall polyphenols improved performance 1.90% (95% CI 0.40-3.39), and a subgroup of 7 quercetin-only studies showed 2.82% (95% CI 2.05-3.58) improv TEMPERED: pools POLYPHENOLS as a class, not quercetin isolated. |
| Mazza OB et al 2025 · study_type: RCT | RCT | contradicts | moderate | RCT crossover, trained male cyclists (n=14, VO2peak ~63 mL/kg/min), combined mangiferin (14.6 mg/h) + quercetin (23.9 mg/h) during 4-h intermittent cycling; no difference vs control in sprint power decline or post-protocol 15-min TT power ( |
| Martin-Rincon M et al 2020 · study_type: RCT | RCT | mixed | low | RCT, recreational runners (n=57), 140 mg mangiferin + 140 mg quercetin around a 10 km race; competition (race) times were similar between groups, but the combo reduced 24h post-race jump-performance loss (9.4±11.5% vs 3.9±5.2%, p=.036) — co |
| Harlow J et al 2024 · study_type: observational | observational | contradicts | moderate | Systematic review of 16 RCTs/quasi-experimental trials in active-duty (trained) military personnel; of 4 studies testing phytonutrient extracts (oregano, beetroot juice, quercetin, resveratrol) for muscle performance, quercetin did not impr |
| Ruiz-Iglesias P et al 2021 · study_type: observational | observational | mixed | moderate | Systematic review of 51 clinical studies (54 articles, 1,288 subjects, mix of untrained and trained) since 2005; only 25% of quercetin-specific trials reported improved exercise performance vs 28% for flavanol-enriched extracts and 54% for |
| Pelletier DM et al 2013 · International journal of sport nutrition and exercise metabolism | meta-analysis | mixed | moderate | MA of 7 quercetin RCTs (n=288); endurance performance improved 0.74% overall (95% CI 0.10-1.39, p=.02) but only in untrained subjects (0.83%, p=.02; trained: 0.09%, p=.92), and VO2max rose 1.94% (95% CI 0.30-3.59, p=.02) — magnitude-based i |
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