The Claim

Six weeks of caffeine supplementation during resistance training has no significant effect on one-repetition maximum strength in the bench press or bench pull, or on muscular endurance at 60% of 1RM, in recreationally active men.

Source: Six weeks of caffeine supplementation enhances muscle thickness without augmenting strength gains—a randomized controlled trial

What the research says

Supports is higher

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

Supports
54score
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 caffeine supplements for six weeks while doing resistance training does not increase maximum strength in the bench press or bench pull, and does not improve the ability to perform repeated lifts at 60% of maximum capacity in recreationally active men.

See the scientific wording

Six weeks of caffeine supplementation during resistance training does not significantly improve one-repetition maximum strength in the bench press or bench pull, or muscular endurance at 60% of 1RM, in recreationally active men, indicating that any hypertrophic effect is not accompanied by enhanced strength or fatigue resistance.

Why this might work

Caffeine blocks adenosine receptors in the brain and muscles, but this does not increase how strongly nerves signal muscles to contract or how long muscles can keep working under load, so muscle size can grow without strength or endurance improving.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Six weeks of caffeine supplementation enhances muscle thickness without augmenting strength gains—a randomized controlled trial

    Taking caffeine for six weeks while lifting weights may make your arm muscles a little bigger, but it won’t make you stronger or let you do more reps before getting tired — and that’s exactly what this study found.

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.