The Claim

Consumption of 710 mL/day of watermelon juice providing approximately 1.65 g of L-citrulline for 8 weeks in non-athlete men undergoing endurance training is associated with increased muscle thickness but no improvement in exercise performance.

Source: The Effects of Watermelon Juice on Muscle Hypertrophy, Exercise Performance, and Muscle Soreness in Non‐Athlete Men Undergoing Endurance Training: A Randomized Controlled Trial

What the research says

Supports is higher

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

Supports
74score
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.

Correlation
1 study reviewed
In plain English

In non-athlete men doing endurance training, drinking 710 mL of watermelon juice daily for 8 weeks is linked to greater muscle thickness but no change in exercise performance.

See the scientific wording

Watermelon juice consumption (710 mL/day, ~1.65 g L-citrulline) for 8 weeks in non-athlete men undergoing endurance training is associated with increased muscle thickness but not improved exercise performance, suggesting its primary benefit may lie in recovery and adaptation rather than acute ergogenic enhancement.

Why this might work

When someone drinks watermelon juice, the L-citrulline in it gets turned into arginine in the kidneys. Arginine is used to make nitric oxide, which opens up blood vessels in the muscles. This lets more blood flow through, bringing in oxygen and nutrients while removing waste products. The improved blood flow helps muscles repair themselves faster after exercise and grow thicker over time, even if performance doesn't improve right away.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: The Effects of Watermelon Juice on Muscle Hypertrophy, Exercise Performance, and Muscle Soreness in Non‐Athlete Men Undergoing Endurance Training: A Randomized Controlled Trial

    Drinking watermelon juice every day while training made men’s chest and thigh muscles slightly thicker over time, but didn’t help them run faster or lift heavier — so it helps muscles recover and grow, not boost performance right away.

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.