Beetroot juice supplements fail to improve swimming performance or alter post-exercise blood lactate concentrations among competitive and recreational athletes, according to a systematic review and meta-analysis published in Scientific Reports by L. Vega-Monzó and colleagues. Researchers analyzed data across 12 studies, including nine quantitative trials involving 120 swimmers, to test whether the popular nitrate-rich supplement translates its reported running and cycling benefits to the pool.

Evaluating Dietary Nitrate Supplementation in Swimming Performance

Prior research demonstrates that beetroot juice and dietary nitrate supplements can improve exercise efficiency and recovery in land-based endurance sports by increasing nitric oxide bioavailability. Doses ranging from 5 to 16.8 mmol of nitrate taken two to three hours before exercise typically reduce submaximal oxygen consumption and improve energy efficiency in activities like cycling and running. However, researchers examining aquatic sports found a distinct lack of swimming-specific data.

To address this gap, the study evaluated randomized controlled trials using the PICOS criteria. Investigators compared acute and chronic beetroot juice or nitrate supplementation against placebo or no supplementation controls among swimmers of varying skill levels. The pooled quantitative analysis revealed no statistically significant difference in time-trial performance times between athletes taking the supplement and those given a placebo.

Physiological Responses and Perceived Exertion Outcomes

While speed remained unaffected, the meta-analysis identified a small but statistically significant reduction in rating of perceived exertion (RPE) across seven studies involving 100 swimmers using the Borg 6–20 and CR-10 scales. Athletes reported that swimming efforts felt marginally easier following supplementation. Researchers noted that the consistency and practical relevance of this perceptual effect remain uncertain, as it did not translate into measurable performance gains.

Post-exercise blood lactate concentrations showed no significant variation between supplemented groups and placebo groups across six studies covering 69 swimmers. According to the study authors, these parallel lactate responses reflect similar post-exercise metabolic demands rather than any performance-enhancing or detrimental physiological shift. Subgroup analyses sorting maximum sprints, prolonged sprints, and middle-distance races by energy systems confirmed that supplementation benefits did not vary by effort duration.

Frequently Asked Questions

Does beetroot juice improve swimming speed?

No. The meta-analysis found no statistically significant improvement in swimming time-trial performance among athletes who consumed beetroot juice or dietary nitrate supplements.

How does beetroot juice affect perceived exertion in swimmers?

Studies show a small reduction in the rating of perceived exertion, meaning swimming sessions may feel slightly easier, though this does not result in faster race times.

What is the recommended dose of dietary nitrate tested in these studies?

The research evaluated doses typically ranging from 5 to 16.8 mmol (300 to 1041 mg) of nitrate taken as a single dose prior to exercise.

Join the Discussion

Have you experimented with dietary nitrate supplements in your training routine? Share your experiences in the comments below, and subscribe to our newsletter for the latest updates on sports science research.