Why this amino acid helps cyclists go faster
Oral L-citrulline supplementation enhances cycling time trial performance in healthy trained men: Double-blind randomized placebo-controlled 2-way crossover study
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
L-citrulline improved concentration and reduced mental fatigue—despite no change in VO2 or heart rate.
Most ergogenic aids boost physical output, but this one improved mental clarity during peak exertion—something rarely measured or reported in sports science.
Practical Takeaways
Take 2.4g of L-citrulline daily for 7 days, plus another 2.4g 1 hour before a high-intensity workout or race.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
L-citrulline improved concentration and reduced mental fatigue—despite no change in VO2 or heart rate.
Most ergogenic aids boost physical output, but this one improved mental clarity during peak exertion—something rarely measured or reported in sports science.
Practical Takeaways
Take 2.4g of L-citrulline daily for 7 days, plus another 2.4g 1 hour before a high-intensity workout or race.
Publication
Journal
Journal of the International Society of Sports Nutrition
Year
2016
Authors
Takashi Suzuki, M. Morita, Yoshinori Kobayashi, A. Kamimura
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Claims (6)
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.
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.
Taking a specific supplement called L-citrulline every day for a week, plus a little more before working out, can boost a key chemical in your blood by about three-quarters — and that chemical helps your body make nitric oxide, which is good for blood flow.
Taking L-citrulline by mouth raises your blood levels of L-arginine better than taking L-arginine directly, because your body processes L-citrulline more efficiently and doesn’t break it down too early in the liver.
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.