The Claim

Acute supplementation with L-arginine and citrulline malate has no effect on performance during the CrossFit 'Cindy' workout in trained men, despite the presence of a learning effect across test sessions.

Source: Acute effects of combined supplementation of L-arginine and citrulline malate on aerobic, anaerobic, and CrossFit exercise performance

What the research says

Supports is higher

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

Supports
71score
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.

Description
1 study reviewed
In plain English

Taking L-arginine and citrulline malate before the CrossFit 'Cindy' workout does not change performance in trained men, even though performance improves over repeated test sessions due to practice.

See the scientific wording

Acute L-arginine and citrulline malate supplementation does not improve performance in the CrossFit 'Cindy' workout (pull-ups, push-ups, squats) in trained men, despite a learning effect observed across test sessions.

Why this might work

When someone takes L-arginine and citrulline malate, the body converts citrulline into arginine, which is then used to make nitric oxide. Nitric oxide opens up blood vessels, allowing more blood to flow to muscles. This should improve oxygen and nutrient delivery, but in this case, it does not lead to better performance in the CrossFit 'Cindy' workout.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Acute effects of combined supplementation of L-arginine and citrulline malate on aerobic, anaerobic, and CrossFit exercise performance

    The study gave trained men a common workout supplement before they did a CrossFit workout with pull-ups, push-ups, and squats, and found they didn’t do more rounds than when they took a placebo. So the supplement didn’t help.

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.