The Claim

Acute ingestion of caffeine at a dosage of 5 mg/kg reduces pain perception during high-intensity resistance exercise performed at 90% of one-repetition maximum in young, healthy adults, with a more pronounced effect observed during the bench press exercise, indicating a modulatory influence on nociceptive signaling during maximal effort.

Source: Effects of acute caffeine ingestion on muscle strength, muscular endurance, rating of perceived exertion, and pain perception during strength exercise until the failure

What the research says

Supports is higher

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

Supports
48score
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

Taking 5 mg of caffeine per kilogram of body weight before intense weightlifting reduces the sensation of pain during maximal effort exercises, especially during the bench press, by altering how pain signals are processed.

See the scientific wording

Acute caffeine ingestion at 5 mg/kg reduces pain perception during high-intensity resistance exercise (90% 1RM) in young, healthy adults, particularly during the bench press, suggesting a modulatory effect on nociceptive signaling during maximal effort.

Why this might work

Caffeine stops a natural chemical in the brain from signaling fatigue and pain, so when muscles are pushed to their limit, the brain interprets the effort as less painful.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Effects of acute caffeine ingestion on muscle strength, muscular endurance, rating of perceived exertion, and pain perception during strength exercise until the failure

    Caffeine made people feel less pain when lifting their heaviest weights, especially during bench presses, compared to when they took a sugar pill. So yes, caffeine helps make heavy lifting feel a little less painful.

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.