The Claim

Watermelon juice supplementation has no effect on time-to-exhaustion during severe-intensity exercise in healthy recreationally-active adult males, despite increasing plasma nitrite concentrations and muscle oxygenation during moderate-intensity exercise.

Source: Two weeks of watermelon juice supplementation improves nitric oxide bioavailability but not endurance exercise performance in humans.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
46score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

Drinking watermelon juice does not make healthy active men last longer during high-intensity exercise, even though it raises plasma nitrite levels and improves muscle oxygenation during moderate exercise.

See the scientific wording

Watermelon juice supplementation does not improve time-to-exhaustion during severe-intensity exercise in healthy recreationally-active adult males, despite increasing plasma nitrite and muscle oxygenation during moderate exercise.

Why this might work

Watermelon juice provides L-citrulline, which the body converts into arginine, then into nitric oxide. Nitric oxide opens blood vessels, increasing blood flow and oxygen delivery to muscles during moderate exercise. However, during intense exercise, muscles demand oxygen faster than blood flow can supply it, and the extra oxygen from nitric oxide does not help the muscles work longer before fatigue sets in.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Two weeks of watermelon juice supplementation improves nitric oxide bioavailability but not endurance exercise performance in humans.

    Drinking watermelon juice for two weeks didn't help healthy men last longer during intense workouts, even though it made their blood and muscles feel more oxygenated during easier exercise.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.