Beetroot juice and oxygen use during cycling in trained athletes
What it found
Seven days of high-dose beetroot juice did not change how efficiently well-trained cyclists used oxygen during moderate cycling.
This was tested in people exercising in normal air and in low-oxygen conditions.
What they found
Studies in people
Oxygen use during cycling
Beetroot juice made a tiny 2.1% drop in one measure of the oxygen response when starting to cycle. But it did not change overall oxygen use once cycling settled into a steady pace, in either normal or low-oxygen air.
Muscle oxygen levels
Sensors on the thigh showed that beetroot juice did not change how fast the muscles extracted oxygen. It also did not change the balance between oxygen delivered to the muscle and oxygen used by it.
Exercise efficiency
The amount of energy the cyclists got from each pedal stroke stayed about the same whether they drank beetroot juice or the placebo.
Blood pressure at rest
Resting blood pressure was about the same after seven days of beetroot juice compared to the placebo. Systolic pressure was 126 mm Hg with beetroot and 124.2 mm Hg with placebo.
Nitrate levels in blood
Drinking the beetroot juice raised blood nitrate levels sharply, from 34 to 713 µm. The placebo contained almost no nitrate.
What the authors conclude
- They conclude that seven days of high-dose beetroot juice did not improve oxygen use or exercise efficiency during moderate cycling in well-trained athletes.
- They suggest beetroot juice might still affect performance at harder exercise levels that rely more on fast-twitch muscle fibers.
How it was done
Past work suggested beetroot juice might help the body use oxygen more efficiently during exercise, especially when oxygen is scarce. Scientists wanted to see if a large daily dose over several days would help highly trained athletes, who already have naturally higher nitrate levels than less active people.
Twelve well-trained cyclists drank 140 ml of concentrated beetroot juice or a placebo with no nitrate every day for seven days. On two of those days they cycled at a moderate pace while researchers measured their oxygen use and muscle oxygen levels. They repeated the cycling tests breathing normal air and breathing air with reduced oxygen.
What it can’t tell you
- This trial only looked at moderate-intensity cycling, so it cannot show what happens during harder efforts or different sports.
- The study included only twelve well-trained male cyclists, so the results may not apply to casual exercisers or women.
Who paid
- Authors work at
- Aalborg University, Denmark; Karolinska Institutet, Sweden; Center for Robotics Research, United Kingdom
The paper
- Title
- Multiple-day high-dose beetroot juice supplementation does not improve pulmonary or muscle deoxygenation kinetics of well-trained cyclists in normoxia and hypoxia
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Rokkedal-Lausch T, Franch J, Poulsen MK, et al (2021). Multiple-day high-dose beetroot juice supplementation does not improve pulmonary or muscle deoxygenation kinetics of well-trained cyclists in normoxia and hypoxia. Nitric oxide. doi:10.1016/j.niox.2021.03.006Free full textPubMed 33831566DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error