Study · Nitric oxide · 2021

Beetroot juice and oxygen use in well-trained cyclists

What it found

In 12 well-trained cyclists, taking beetroot juice for seven days did not change how quickly their muscles or lungs used oxygen during moderate cycling, in normal air or low-oxygen air.

The authors say it also did not change exercise efficiency.

What they found

Studies in people

Oxygen uptake speed

Beetroot juice did not change how fast oxygen uptake rose at the start of moderate cycling, in normal air or low-oxygen air.

Muscle deoxygenation speed

Beetroot juice did not change how fast the thigh muscle became deoxygenated during the rides.

Exercise efficiency

Exercise efficiency during moderate cycling was about the same with beetroot juice and placebo.

Oxygen uptake amplitude

The size of the rise in oxygen uptake was slightly smaller with beetroot juice, by about 2.1%, but steady oxygen uptake and raw oxygen uptake did not differ.

Blood pressure

Resting blood pressure was unchanged with beetroot juice compared with placebo.

Low-oxygen air effects

Low-oxygen air slowed oxygen uptake and muscle deoxygenation and raised heart rate, but beetroot juice did not change these responses.

What the authors conclude

“Altogether, these results demonstrate that multiple-day, high-dose BR supplementation does not alter exercise efficiency or oxygen uptake kinetics during normoxia and hypoxia in well-trained athletes.”
Rokkedal-Lausch T, Franch J, Poulsen MK, et al, 2021

Also in their conclusions

  • They conclude that multiple-day, high-dose beetroot juice supplementation does not improve muscle oxygen or oxygen uptake kinetics or exercise efficiency during moderate-intensity cycling in well-trained athletes.
  • They suggest that beetroot juice may still have benefits during higher exercise intensities that use more fast-twitch muscle fibers.

How it was done

Beetroot juice has been reported to lower the oxygen cost of exercise and speed up oxygen uptake in untrained and moderately trained people, especially when oxygen is low. The authors wanted to see if several days of a high dose would do the same in well-trained athletes.

Twelve well-trained cyclists took beetroot juice or a nitrate-depleted placebo for seven days, then did three six-minute rides at moderate intensity in normal air and in low-oxygen air. The researchers measured oxygen uptake and muscle deoxygenation during the rides.

What it can’t tell you

  • The study only included 12 well-trained cyclists, so the results may not apply to other people or to other types of exercise.
  • The cyclists rode at a moderate intensity, so the findings do not show what happens at higher intensities.

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 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error