The Claim

The ergogenic effect of caffeine on cycling performance is not mediated by differences in serum caffeine concentration between morning and evening trials, as serum caffeine concentrations were statistically similar regardless of time of day.

Source: Time of Day and Training Status Both Impact the Efficacy of Caffeine for Short Duration Cycling Performance

What the research says

Supports is higher

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

Supports
64score
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.

How it works
1 study reviewed
In plain English

Caffeine improves cycling performance equally in the morning and evening, and this effect is not due to differences in how much caffeine is in the blood at those times.

See the scientific wording

Caffeine’s ergogenic effect on cycling performance is not explained by differences in serum caffeine concentration between morning and evening trials, as levels were similar regardless of time of day.

Why this might work

Caffeine blocks a natural chemical in the body that slows down muscle signaling, allowing muscles to contract more efficiently during prolonged cycling, especially when the effort is steady and not all-out.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Time of Day and Training Status Both Impact the Efficacy of Caffeine for Short Duration Cycling Performance

    The study gave people the same amount of caffeine in the morning and evening, and they performed better at different times — even though the caffeine in their blood was probably the same. So the difference in performance must be because of their body’s internal clock or how tired they were, not how much caffeine was in their system.

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.