The Claim

In non-athlete men undergoing 8 weeks of endurance training, daily consumption of 710 mL of watermelon juice (containing approximately 1.65 g L-citrulline) is associated with a mean increase of 2.00 mm in pectoralis major muscle thickness and 1.70 mm in rectus femoris muscle thickness.

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

Non-athlete men who drank 710 mL of watermelon juice daily for 8 weeks while doing endurance training showed an average increase of 2.00 mm in pectoralis major muscle thickness and 1.70 mm in rectus femoris muscle thickness.

See the scientific wording

In non-athlete men undergoing 8 weeks of endurance training, daily consumption of 710 mL of watermelon juice (containing approximately 1.65 g L-citrulline) is associated with a mean increase of 2.00 mm in pectoralis major muscle thickness and 1.70 mm in rectus femoris muscle thickness, suggesting a potential role in enhancing muscle adaptation to endurance exercise.

Why this might work

L-citrulline from watermelon juice is converted into arginine, which the body uses to make nitric oxide. Nitric oxide opens up blood vessels, allowing more blood to flow into muscles during and after exercise. This brings more oxygen and nutrients while removing waste products, which helps muscles repair and grow thicker. Antioxidants in the juice protect nitric oxide from being destroyed, making this effect stronger.

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

    Men who drank watermelon juice before their workouts for 8 weeks ended up with slightly thicker chest and thigh muscles than those who drank a placebo, even though they did the same workouts. This suggests the juice might help muscles grow a bit more during training.

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.

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