The Claim
Caffeine supplementation at 6 mg/kg body weight improves 3-km cycling time trial performance by 2.3% in the morning and by 1.4% in the evening for adult male cyclists, with a greater performance improvement observed in the morning, indicating that time of day modulates the ergogenic effect of caffeine in this population.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
For adult male cyclists, taking 6 mg of caffeine per kilogram of body weight improves 3-km cycling time trial performance by 2.3% in the morning and by 1.4% in the evening, with a larger improvement in the morning.
See the scientific wording
Caffeine supplementation at 6 mg/kg body weight likely improves 3-km cycling time trial performance by 2.3% in the morning and 1.4% in the evening for adult male cyclists, with greater benefits observed in the morning, suggesting time of day modulates caffeine's ergogenic effect in this population.
Caffeine blocks a natural chemical in the body that slows down muscle activity, especially in the slow-twitch muscle fibers that help with endurance. This allows more muscle fibers to fire during cycling, making the rider more efficient and able to maintain power longer, especially in the morning when the body's natural rhythm makes these fibers more responsive.
What the research says
1 studyThis study found that when male cyclists took a specific dose of caffeine before a short bike race, they rode faster in the morning than in the evening — just like the claim says. The numbers match: about 2.3% faster in the morning and 1.4% faster in the evening.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.