Analysis Version
v1
History
Back to Study: Oral L-citrulline supplementation enhances cycling...
causal
Analysis v1
66
Pro
0
Against

Taking a supplement called L-citrulline every day for a week, plus a little more right before riding a bike for 4 km, makes healthy, fit men feel less tired and more focused right after they finish the ride.

Claim Language

Language Strength

definitive

Uses definitive language (causes, prevents, cures)

The claim uses 'significantly improves', which implies a direct, measurable, and certain effect — a definitive causal language indicating the intervention produces a clear outcome without uncertainty.

Context Details

Domain

exercise_science

Population

human

Subject

healthy trained men

Action

significantly improves

Target

subjective ratings of muscle fatigue and concentration

Intervention Details

Type: supplement
Dosage: 2.4g/day for 7 days + 2.4g pre-exercise
Duration: 7 days plus single pre-exercise dose

Gold Standard Evidence Needed

According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.

Evidence from Studies

Supporting (1)

66
66

Oral L-citrulline supplementation enhances cycling time trial performance in healthy trained men: Double-blind randomized placebo-controlled 2-way crossover study

Randomized Controlled Trial
Human
2016

The study gave men the same L-citrulline pills as the claim describes, had them ride a stationary bike, and found they felt less tired and more focused afterward — exactly what the claim says.

Contradicting (0)

0
No contradicting evidence found

Source Study

Oral L-citrulline supplementation enhances cycling time trial performance in healthy trained men: Double-blind randomized placebo-controlled 2-way crossover study

Score: 66
DOI: 10.1186/s12970-016-0117-z

Similar Assertions

Taking a specific amino acid called L-citrulline every day for a week, plus a little more before a bike race, helps men who are already fit ride harder for 4 kilometers without getting more out of breath — meaning their bodies use energy more efficiently.

66
0
88%

Taking a specific amino acid supplement called L-citrulline every day for a week, then taking one more dose an hour before a short, intense bike ride, helps trained male cyclists finish the ride 1.5% faster.

66
0
87%

Taking a specific dose of L-citrulline for 10 days doesn’t change how your body uses sugar or handles lactic acid when you bike really hard, so it doesn’t help or hurt your energy or fatigue during intense exercise.

53
0
85%

Taking L-citrulline pills for 10 days doesn’t help healthy, moderately active young adults ride harder or longer on a bike at a tough pace.

53
0
85%

Taking a specific dose of L-citrulline for 10 days doesn’t make you bike harder, faster, or feel less tired—even though some people think it might help. Your heart, lungs, and muscles act the same as if you didn’t take it.

53
0
82%